DENTAL ERUPTION AND MINERALIZATION IN IRAQI KURDISTAN

By

DAVID Z.C. HINES

A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT

OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

UNIVERSITY OF FLORIDA

2016

© 2016 David Z.C. Hines

To my mother, who is here to see it

To my father, who is not To my wife, who got here first To my committee, who waited

To the RCLO and the ICMP, who took me to Iraq To the Iraqi people, who deserve better

And to MUT0002 EV094 C52, whose name is still unknown I owe a great debt to all of you.

4

ACKNOWLEDGMENTS

This dissertation would not have been possible without the kind assistance of the

KRG government and my Iraqi colleagues. To that end, I gratefully acknowledge the

official cooperation of Dr. Taher A. Hawramy, Minister of Health, Kurdistan Region, and

Dr. Yasin Karim, Director of the Medicolegal Institute in Erbil. Dr. Yasin’s deputy, Dr.

Hawre Dlzar, also head of Erbil’s Mass Graves department, provided assistance,

consultation, and friendship, and enabled the author to sit in on the Erbil age estimation

committee to observe firsthand the challenges faced by the committee. Dr. Faisal

Bilbas, a valued colleague and friend, was indispensible in arranging introductions and

in negotiating the KRG bureaucracy, and he was extraordinarily gracious in lending the

benefit of his long experience on Erbil’s age estimation committee.

I am especially grateful to the aid and forbearance of my chair Michael Warren

and my doctoral committee Jonathan Bloch, Jason Byrd, and John Krigbaum, without

whom I could not have finished. The value of their guidance cannot be underestimated,

and I am deeply thankful for their steadfast support at the university, which was

essential during my time in Iraq and the long period of production of this work.

From the International Commission on Missing Persons, I thank my supervisors

Thomas Parsons, Ian Hanson, Duncan Spinner, and Johnathan McCaskill, and

especially thank my close colleagues James Fenn and James Murphy. The production

assistance of Nihen Himdad Refiq was greatly appreciated during the initial phases of

data collection and consolidation.

Finally, I wish to extend my gratitude to Dr. Sonny Trimble and the staff of the

Regime Crimes Liaison Office Mass Graves Investigation Team (RCLO/MGIT), with

whom I first went to Iraq. I’d ride the river with you any time.

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TABLE OF CONTENTS

page

ACKNOWLEDGMENTS .................................................................................................. 4

LIST OF TABLES ............................................................................................................ 7

LIST OF FIGURES .......................................................................................................... 9

LIST OF ABBREVIATIONS ........................................................................................... 13

ABSTRACT ................................................................................................................... 14

CHAPTER

1 INTRODUCTION .................................................................................................... 15

Biological Profile: a Challenge ................................................................................ 15 Age Estimation in Iraq: the Living ........................................................................... 18 Age Estimation in Iraq – the Dead .......................................................................... 22

Age Estimation in Iraq – Solutions .......................................................................... 24

2 REVIEW OF THE LITERATURE, PART I: DENTAL AGE ESTIMATION .............. 26

Background ............................................................................................................. 26 Dental Eruption and Mineralization ......................................................................... 29

The Atlas-Based Approach ..................................................................................... 30 The Scoring Approach ............................................................................................ 37 Variability and Regional Studies ............................................................................. 40

3 REVIEW OF THE LITERATURE, PART II: PHYSICAL ANTHROPOLOGY OF IRAQ ....................................................................................................................... 47

Beginnings of Physical Anthropology in Iraq ........................................................... 47 Population Standards: Solutions ............................................................................. 49 Middle East ............................................................................................................. 52

4 METHODS .............................................................................................................. 54

Permissions and IRB Approval ............................................................................... 54 Dataset Preparation and Database Construction .................................................... 55 Analysis of Findings and Standard Construction .................................................... 59

Checking against Control ........................................................................................ 60 A Note on Error ....................................................................................................... 62

5 RESULTS ............................................................................................................... 64

6

Organization of this Chapter ................................................................................... 64

Experimental Group Results ................................................................................... 64 Dentition Overview ..................................................................................... 65

Dentition summary ..................................................................................... 91 The Kurdish Standard ........................................................................................... 102 Comparison .......................................................................................................... 108 Evaluation Against Control .................................................................................... 121 Comparison of Standards ..................................................................................... 123

6 CONCLUSIONS ................................................................................................... 147

LIST OF REFERENCES ............................................................................................. 148

BIOGRAPHICAL SKETCH .......................................................................................... 171

7

LIST OF TABLES

Table page 2-1 Correspondence between Moorees (1963) stages, Demirjian (1973) stages,

and Al-Qahtani et al. (2010) (after McVeigh, 1999). ........................................... 39

4-1 Numbers of individuals in experimental and control datasets. ............................ 56

4-2 Mineralization and eruption stages, with corresponding numeric values. ........... 60

4-3 Ages and corresponding error ranges in Ubelaker standard. ............................. 62

5-1 Significant difference in mineralization means, male left vs. male right. ............. 92

5-2 Significant difference in eruption means, male left vs. male right. ...................... 92

5-3 Significant difference in mineralization means, female left vs. female right. ....... 93

5-4 Significant difference in eruption means, female left vs. female right. ................ 93

5-5 Significant difference in mineralization means, pooled left vs. pooled right. ....... 93

5-6 Significant difference in eruption means, pooled left vs. right. ............................ 94

5-7 Significant difference in mineralization means, pooled left vs male left. ............. 94

5-8 Significant difference in eruption means, pooled left vs male left. ...................... 94

5-9 Significant difference in mineralization means, pooled right vs male right. ......... 95

5-10 Significant difference in eruption means, pooled right vs male right. .................. 95

5-11 Significant difference in mineralization means, pooled left vs female left. .......... 95

5-12 Significant difference in eruption means, pooled left vs female left. ................... 96

5-13 Significant difference in mineralization means, pooled right vs female right. ...... 96

5-14 Significant difference in eruption means, pooled right vs female right. ............... 96

5-15 Significant difference in mineralization means, female left vs. male left. ............ 98

5-16 Significant difference in eruption means, female left vs. male left. ..................... 99

5-17 Significant difference in mineralization means, female right vs. male right. ...... 100

5-18 Significant difference in eruption means, female right vs. male right. ............... 101

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5-19 The Kurdish Standard. Mineralization and Eruption are shown in alternating rows. ................................................................................................................. 103

5-20 Mineralization and eruption stages, with corresponding numeric values. ......... 124

5-21 Ubelaker standard, mineralization and eruption stages (sum method). ............ 126

5-22 AlQahtani standard, mineralization and eruption stages (sum method). .......... 126

5-23 Kurdish standard, mineralization and eruption stages (sum method). .............. 127

5-24 Kurdish standard aged within one year. ........................................................... 134

5-25 AlQahtani standard aged within one year. ........................................................ 135

5-26 Ubelaker standard aged within one year. ......................................................... 136

5-27 Kurdish standard aged exactly. ........................................................................ 137

5-28 AlQahtani standard aged exactly. ..................................................................... 138

5-29 Ubelaker standard aged exactly. ...................................................................... 139

5-30 Kurdish standard overestimate. ........................................................................ 140

5-31 AlQahtani standard overestimate. .................................................................... 141

5-32 Ubelaker standard overestimate. ...................................................................... 142

5-33 Kurdish standard underestimate. ...................................................................... 143

5-34 AlQahtani standard underestimate. .................................................................. 144

5-35 Ubelaker standard underestimate. .................................................................... 145

5-36 Comparison of standards’ mean differences between actual age and estimated age. .................................................................................................. 146

9

LIST OF FIGURES

Figure page 4-1 Experimental database, scoring view, showing dropdown menu........................ 57

4-2 Control database, chart view. ............................................................................. 58

5-1 Mean stages of mineralization, first maxillary deciduous incisor......................... 65

5-2 Mean stages of eruption, first maxillary deciduous incisor. ................................. 66

5-3 Mean stages of mineralization, second maxillary deciduous incisor. .................. 66

5-4 Mean stages of eruption, second maxillary deciduous incisor. ........................... 67

5-5 Mean stages of mineralization, maxillary deciduous canine. .............................. 67

5-6 Mean stages of eruption, maxillary deciduous canine. ....................................... 68

5-7 Mean stages of mineralization, maxillary deciduous first molar. ......................... 68

5-8 Mean stages of eruption, maxillary deciduous first molar. .................................. 69

5-9 Mean stages of mineralization, maxillary deciduous second molar. ................... 69

5-10 Mean stages of eruption, maxillary deciduous second molar. ............................ 70

5-11 Mean stages of mineralization, mandibular deciduous first incisor. .................... 70

5-12 Mean stages of mineralization, mandibular deciduous first incisor. .................... 71

5-13 Mean stages of mineralization, mandibular deciduous second incisor. .............. 71

5-14 Mean stages of eruption, mandibular deciduous second incisor. ....................... 72

5-15 Mean stages of mineralization, mandibular deciduous canine. .......................... 72

5-16 Mean stages of eruption, mandibular deciduous canine. .................................... 73

5-17 Mean stages of mineralization, mandibular deciduous first molar. ..................... 73

5-18 Mean stages of eruption, mandibular deciduous first molar. .............................. 74

5-19 Mean stages of mineralization, mandibular deciduous second molar. ................ 74

5-20 Mean stages of eruption, mandibular deciduous second molar. ......................... 75

5-21 Mean stages of mineralization, maxillary permanent first incisor. ....................... 75

10

5-22 Mean stages of mineralization, maxillary permanent first incisor. ....................... 76

5-23 Mean stages of mineralization, maxillary permanent second incisor. ................. 76

5-24 Mean stages of eruption, maxillary permanent second incisor. .......................... 77

5-25 Mean stages of mineralization, maxillary permanent canine. ............................. 77

5-26 Mean stages of eruption, maxillary permanent canine. ...................................... 78

5-27 Mean stages of mineralization, maxillary permanent first premolar. ................... 78

5-28 Mean stages of eruption, maxillary permanent first premolar. ............................ 79

5-29 Mean stages of mineralization, maxillary permanent second premolar. ............. 79

5-30 Mean stages of eruption, maxillary permanent second premolar. ...................... 80

5-31 Mean stages of mineralization, maxillary permanent first molar. ........................ 80

5-32 Mean stages of eruption, maxillary permanent first molar. ................................. 81

5-33 Mean stages of mineralization, maxillary permanent second molar. .................. 81

5-34 Mean stages of eruption, maxillary permanent second molar. ........................... 82

5-35 Mean stages of mineralization, maxillary permanent third molar. ....................... 82

5-36 Mean stages of mineralization, maxillary permanent third molar. ....................... 83

5-37 Mean stages of mineralization, mandibular permanent first incisor. ................... 83

5-38 Mean stages of eruption, mandibular permanent first incisor. ............................ 84

5-39 Mean stages of mineralization, mandibular permanent second incisor. ............. 84

5-40 Mean stages of eruption, mandibular permanent second incisor........................ 85

5-41 Mean stages of mineralization, mandibular permanent canine. .......................... 85

5-42 Mean stages of eruption, mandibular permanent canine. ................................... 86

5-43 Mean stages of mineralization, mandibular first premolar. ................................. 86

5-44 Mean stages of eruption, mandibular first premolar. ........................................... 87

5-45 Mean stages of mineralization, mandibular second premolar. ............................ 87

5-46 Mean stages of eruption, mandibular second premolar. ..................................... 88

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5-47 Mean stages of mineralization, permanent mandibular first molar. ..................... 88

5-48 Mean stages of eruption, permanent mandibular first molar. .............................. 89

5-49 Mean stages of mineralization, permanent mandibular second molar. ............... 89

5-50 Mean stages of eruption, permanent mandibular second molar. ........................ 90

5-51 Mean stages of mineralization, permanent mandibular third molar. ................... 90

5-52 Mean stages of eruption, permanent mandibular third molar. ............................ 91

5-53 Mineralization of maxillary deciduous dentition, Kurdish standard.................... 109

5-54 Mineralization of maxillary deciduous dentition, AlQahtani standard. ............... 109

5-55 Mineralization of maxillary deciduous dentition, Ubelaker standard. ................ 110

5-56 Mineralization of mandibular deciduous dentition, Kurdish standard. ............... 110

5-57 Mineralization of maxillary deciduous dentition, AlQahtani standard. ............... 111

5-58 Mineralization of mandibular deciduous dentition, Ubelaker standard. ............. 111

5-59 Mineralization of maxillary permanent dentition, Kurdish standard. .................. 112

5-60 Mineralization of maxillary permanent dentition, AlQahtani standard. .............. 112

5-61 Mineralization of maxillary permanent dentition, Ubelaker standard. ................ 113

5-62 Mineralization of mandibular permanent dentition, Kurdish standard. .............. 113

5-63 Mineralization of mandibular permanent dentition, AlQahtani standard. ........... 114

5-64 Mineralization of mandibular permanent dentition, Ubelaker standard. ............ 114

5-65 Eruption of maxillary deciduous dentition, Kurdish standard. ........................... 115

5-66 Eruption of maxillary deciduous dentition, AlQahtani standard. ........................ 116

5-67 Eruption of maxillary deciduous dentition, Ubelaker standard. ......................... 116

5-68 Eruption of mandibular deciduous dentition, Kurdish standard. ........................ 117

5-69 Eruption of mandibular deciduous dentition, AlQahtani standard. .................... 117

5-70 Eruption of mandibular deciduous dentition, Ubelaker standard....................... 118

5-71 Eruption of maxillary permanent dentition, Kurdish standard. .......................... 118

12

5-72 Eruption of maxillary permanent dentition, AlQahtani standard. ....................... 119

5-73 Eruption of maxillary permanent dentition, Ubelaker standard. ........................ 119

5-74 Eruption of mandibular permanent dentition, Kurdish standard. ....................... 120

5-75 Eruption of mandibular permanent dentition, AlQahtani standard. ................... 120

5-76 Eruption of mandibular permanent dentition, Ubelaker standard. ..................... 121

5-77 Actual age vs. estimated age, using Kurdish standard atlas. ........................... 122

5-78 Actual age vs. difference between actual and estimated age, using Kurdish standard atlas. .................................................................................................. 123

5-79 Comparison of median scores for each age of left, right, male, female, and pooled individuals of both sexes. ...................................................................... 125

5-80 Midpoints of scores at prescribed age for AlQahtani, Ubelaker, and Kurdish standards. ......................................................................................................... 128

5-81 Actual age (X) vs. estimated age (Y) for all standards. ..................................... 129

5-82 Actual age (X) vs. estimated age (Y) for Kurdish standard, contrasting atlas and scoring methods. ....................................................................................... 129

5-83 Actual age (X) vs. difference between estimated age and actual age (Y) for all standards. .................................................................................................... 130

5-84 Actual age (X) vs. difference from estimated age (Y) for AlQahtani standard. . 131

5-85 Actual age (X) vs. difference from estimated age (Y) for Ubelaker standard. ... 132

5-86 Actual age (X) vs. difference from estimated age (Y) for Kurdish standard (using automated scoring). ............................................................................... 132

5-87 Actual age (X) vs. difference from estimated age (Y) for Kurdish standard (atlas reference image scoring). ....................................................................... 133

13

LIST OF ABBREVIATIONS

ICMP International Commission on Missing Persons.

KRG Kurdish Regional Government (or Governorate). The semi-autonomous Kurdish provinces of Iraq.

MGIT Mass Graves Investigation Team

RCLO Regime Crimes Liaison Office

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Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy

DENTAL ERUPTION AND MINERALIZATION

IN IRAQI KURDISTAN

By

David Z.C. Hines

December 2016

Chair: Michael Warren Major: Anthropology

The use of standards derived from one population to assess the biological profile

of unknown individuals from another population has long been an issue of concern for

anthropologists. In Iraq, as in many nations in the Middle East, study of physical

anthropology has languished for political, cultural, and safety reasons. In the absence of

population-specific standards, Iraq must still devote considerable resources to the

estimation of age in the living and the dead. Iraq faces a growing refugee problem, a

rural populace that often lacks birth certificates, and enormous numbers of mass graves

and missing persons cases. No studies have focused on the Iraqi Kurds, of whom an

estimated 180,000 men, women, and children were killed by the Baathist Iraqi state

during the Anfal Campaign following the Iran-Iraq War.

This work provides timings of dental eruption and mineralization for Iraqi

Kurdistan, based on anonymized panoramic radiographs of 1,222 Iraqi Kurdish

individuals of known age and sex. The model was verified using a control of 195

anonymized panoramic radiographs reserved from the same population. Comparison of

the derived model with existing models shows the Kurdish standard slightly superior at

aging the Kurdish population.

15

CHAPTER 1 INTRODUCTION

Biological Profile: a Challenge

The use of standards derived from one population to assess the biological profile

of unknown individuals from another population has long been an issue of concern for

anthropologists. As the demand for forensic anthropology increases in diverse parts of

the world, many of which have little indigenous experience with physical anthropology,

anthropologists necessarily find themselves applying their methods to populations

different from the populations from which those methods were derived.

The effectiveness of such applications varies considerably. While population

differences are known to exist, many populations have yet to be adequately assessed.

While some diagnostic features show relatively little variation, others exhibit so much

population variation as to render them ineffective. For example, given that women tend

to be shorter than men and exhibit broader pelvises, the bicondylar angle of the femur

should in theory be sexually dimorphic (Heiple and Lovejoy, 1971). Yet while such

dimorphism appears to manifest clinically in higher rates of patellar subluxation in

women (Heiple and Lovejoy, 1971), a study across thirty populations showed few

exhibited statistically significant sexual dimorphism, and that likely related to societal

activity levels (Anderson and Trinkaus, 1997). Even more stable features may exhibit

notable differences. Phenice (1969), for example, reported 96% accuracy in classifying

an American skeletal collection by sex based on morphological traits of the os coxa. An

inexperienced researcher trained by a forensic anthropologist (Ubelaker and Volk,

2002) was able to reproduce these results, successfully determining sex of os coxae

from that same American skeletal collection to 88.4% accuracy using the Phenice

16

technique alone and to 96% when augmenting Phenice with other, more widely

represented traits (e.g., Steyn and Patriquin, 2009). Other researchers, applying the

technique to English, Dutch, and Scottish skeletons, found the accuracy of the

technique much lessened: 83%, 68%, and 59%, respectively (MacLaughlin and Bruce,

1990).

In many cases, the degree of difference between the basis population and the

population being examined may be pronounced yet go undetected (Martrille et al.,

2007). With regard to age estimation, for example, a review of age estimates made by

anthropologists working in Kosovo against the actual ages of the deceased following

positive identification by DNA showed an accuracy of only 42%: that is, only 42% of the

time did the anthropologists’ estimated ranges for age include the true age of the

individual (Komar, 2003). That figure represents the use of American standards to

estimate age for Bosnian skeletons; when Bosnian standards were developed and

employed, the accuracy level rose to 75% (Kimmerle et al., 2008). The limited

applicability of Western anthropological standards to populations of concern has arisen

as an issue in at least two different criminal trials in the Balkans (Kimmerle et al., 2008),

and gave rise to a research project to better understand the differences involved.1

Such findings has led some anthropologists (e.g., Steyn and Patriquin, 2009) to

argue that more attention should be paid to methods that are more likely to be universal,

and others to focus on developing standards for populations of interest. Indeed, a go-to

paper subject for anthropologists is the investigation of applicability of a particular

method to a little-studied population. Despite this, however, no comprehensive atlas of

1 A contributing factor may also include the limited training and inexperience of anthropologists performing the early work in the Balkans.

17

population differences yet exists, and cultural, historical, legal, and methodological

issues often drastically limit the literature and material on which anthropologists may

draw. Many regions, the Middle East among them, are little served.

This dissertation represents the first stages of an ongoing effort to develop

population standards for Iraqi populations and to assess the applicability to those

populations of existing standards. Local efforts to develop modern population standards

for the Middle East have been unfortunately few, in part because cultural norms create

extreme difficulties in creating and maintaining skeletal collections for research. In

conversation with Iraqi colleagues, this author has learned Iraqi archaeologists often

elect to quietly discard pre-Islamic skeletons found during excavation rather than incur

the personal and professional risk associated with being accused of disturbing Muslim

graves. In Suleimaniyah, generally regarded as the most cosmopolitan city in Iraqi

Kurdistan, the mortuary has been shot at by individuals who were upset that their family

members were undergoing legally-mandated autopsy.

Forensic communities in Egypt and Lebanon, in particular, have attempted to

circumvent such difficulties by using medical imaging studies of living people to develop

and evaluate some metrics for their respective populations (e.g., Ayoub et al., 2009;

Kharoshah et al., 2010), but in general the populations are notably underserved.

Despite ancient Mesopotamia’s tremendous historical significance and Iraq’s long

culture of learning, the physical anthropology of Iraq, like that of most of the region as a

whole, has been comparatively neglected (Sołtysiak, 2006). The development of

applicable Iraqi standards will prove useful to forensic practitioners throughout the

18

region, as standards for Iraqi Arabs are likely to be more effective for other regional

Arab populations than are those derived from American and Western European groups.

The author has worked in Iraq for several years: between 2005 and 2007, as

osteoarchaeologist and chief report editor for the Regime Crimes Liaison Office Mass

Graves Investigation Team (RCLO/MGIT), and from 2010 through the end of 2014 as

forensic anthropology trainer for the International Commission on Missing Persons

(ICMP). In these capacities, the lack of local and regional standards, and the need for

them, have been apparent (Steele et al., 2005). Not only does the nature of the Anfal

campaign against the Kurds mean that large numbers of children await recovery from

Iraqi mass graves, but lack of government documentation and a continuing refugee

problem throughout the region mean that the Iraqi government is regularly tasked with

estimating the ages of living people. Many Iraqi children, particularly those born in rural

areas, lack birth certificates, and so a medicolegal determination of age is made when

the child’s age must be certified for educational placement or (in criminal cases) into the

adult or juvenile justice system (Bilbas, personal communication, 2011). Accordingly,

age estimation in Iraq is necessary to serve both the living and the dead.

Age Estimation in Iraq: the Living

In the semi-autonomous Kurdish Regional Governate (KRG), where Erbil is

located, the most important age is eighteen. At that age, a citizen may vote, apply for a

driver’s license, get married, take a job with the government, or join the peshmerga (the

KRG military). Eighteen is also the age at which criminals are subject to the adult, rather

than juvenile, justice system, although the age at which criminals may legally be

executed is 28. As there are no government payments that go out specifically to minor

children, except for the payments to the children of victims of the Anfal, the chief benefit

19

to being under age 18 is having criminal offenses adjudicated in the juvenile justice

system. Even adults, however, may seek to revise their ages, often due to age limits on

access to education, in both public and private institutions. The KRG resident aged

above thirty who desires to renew education is typically told to forget it, so some

individuals running out the clock on their eligibility will attempt to fudge a few more

years.

Moreover, the relative security of Iraqi Kurdistan and the contrasting

destabilization of Syria, in particular, has resulted in the return of an increasing number

of refugees, some of them returnees. This new flood has created new demands on the

age estimation committees. Many who fled KRG in the 1990s threw away their original

Iraqi documentation and received new documents as refugees; now, as they return,

they require KRG identity papers, and age estimation becomes part of this process. As

many people who are not from KRG also desire to move to KRG for security and

economic reasons, there are likely some fraudulent documents employed.

The procedure for age estimation is similar throughout Iraq, but standards may

vary considerably as the matter is left up to local control. The frequency of the

committee meetings may also vary; the age estimation committee in Baghdad is

ongoing, due to greater demand, whereas that in Erbil meets for three hours once a

week. Even in Erbil, however, the demand is high; the three to four members of the

committee are tasked with estimating the ages of between fifty and one hundred cases

per week.

At a typical age estimation committee meeting, there are three committee

members: a radiologist, a dentist, and a forensic doctor (this last is a local qualification,

20

defined under the Iraqi Forensic Law 57 of 1987 as an MD who has taken a degree in

forensics or who has a legally-stipulated amount of experience; forensic pathology as a

specialty is quite rare in Iraq). A session of the age estimation committee in Erbil runs

between nine A.M. and noon. People wishing to receive an estimation wait along a

hallway, and gradually are admitted to the room where the committee operates. The

examinees bring court forms asking for a ruling from the committee. Each patient is

examined by one committee member; there is no peer review unless it is specifically

requested by the individual examiner or unless the examiner is in training. The other

members sign on to the examiner’s findings afterward, as a formality, but unless there

has been a specific request none of them have reviewed the material or the patient.

The ruling is determined either on the spot, based on a brief examination, or the

individuals are referred to radiography. Children are generally handled by dental

examination, to avoid radiography if possible; in Erbil, this examination follows the

standards reproduced in Knight’s Forensic Pathology (Saukko and Knight, 2005), or

whatever other reference text is readily available. Some juveniles are referred to a hand

radiograph, which is evaluated against Greulich and Pyle (1959) standards. The dentist

and radiologist typically focus on juveniles while the forensic doctor takes the adult or

older adolescent cases. Late adolescents are referred to hand or chest radiograph. In

some cases, the individual’s claimed age is given the benefit of the doubt; this is

particularly true in the case of a woman who wishes to get married.

To attend an Age Estimation Committee meeting in Erbil is to vividly realize the

importance of aging not only to mass grave investigations but to the daily lives of Iraqi

21

citizens. Some sample cases from a committee meeting in September 2012 will serve to

illustrate the diversity of problems:

A woman whose identification said she was born in 1991 stated that the identification was incorrect, and she was actually born in 1989. The verification was granted based on her testimony.

A woman born outside KRG provided a foreign passport to correct her DOB on KRG paperwork. The verification was granted.

A young male requested an age estimation that would increase his age in order to allow him to be married. A radiograph was requested and showed his hand to be skeletally mature, but his government identification listed his age as 17. The age revision was not granted and the young man was told he must wait another year to marry.

A woman born in 1990 wished to have her birth year revised to 1993. She was referred to radiography.

A teenage girl’s father stated that his daughter had been born in KRG but had no birth certificate and no identification. She was referred to radiography.

A couple returning to KRG from Iran brought UN refugee paperwork and requested confirmation of their ages so they could receive KRG identification.

A Kurdish woman who had married an Iranian man and had been living in Iran prior to returning to KRG with her children (but sans husband) needed age estimations for her children as part of her efforts to obtain KRG identification and enroll them in school. A complication was that Iran follows the Persian calendar, so birthdates needed some translation.

A woman born in 1985 who had left school in the eighth grade requested her birth year be changed to 1988 in order that she could reapply for education.

A woman came in requesting an age estimate. Her ID stated she was born in 2001; she claimed to be 16, and she physically appeared much older. Her provided hand radiography appeared skeletally mature. The forensic doctor advised the author that misrepresentation of identity was not the legal responsibility of the committee.

A woman born 1991 wished to revise her birth year to 1989. There did not appear to be a legal benefit to this revision. Although a hand radiograph would be of no use, she was referred to radiography anyway. (This is fairly typical of such cases, as the committee prefers to have something they can point to in making their decision.)

22

A child exhibited a dental age of six but a radiographic development (admittedly, on a poorly contrasted radiograph) of perhaps 3.5 years. A brief physical examination showed the boy to be malnourished.

A man requested his son’s age be re-estimated. He said the boy is younger than six but looks older dentally. The desired practical effect is unclear.

A man wanted to have his son estimated as older than his current age so that the boy would be eligible to join the peshmerga. The boy was referred to radiography.

It may thus be seen that age estimation among the living makes a great impact in

many Iraqis’ lives. It determines when people may marry, when they may take up

employment to support themselves and their families. It determines when people may

get a driver’s license to improve their ability to work and travel. It determines when

people may be eligible for an education, and when they are not. It contributes to the

issuing of new documents for refugees. It is a constant need, and a tremendous one.

Age Estimation in Iraq – the Dead

Age estimation is also of considerable importance in identifying the dead. The

scale of Iraq’s mass grave problem is immense. Whereas most countries that contain

mass graves tend to feature graves confined to one temporal period and a relatively

common signature, Iraqi mass graves exhibit a diversity of signatures, temporal period,

and victims. There are anonymous, numbered political cemeteries containing the bodies

of the disappeared; there are mass graves on military bases used for executing

prisoners; there are mass graves containing soldiers from the Gulf War and the Iran-

Iraq War; there are mass graves containing Kurdish peshmerga killed in fights with the

Iraqi army, and Kurdish partisans from their fights with each other during the Braw

Kuzhi, or “Brothers’ War;” there are graves from the 1988 Anfal Campaign of the

Baathist military against the Kurds (Fenn et al., 2014). Additional existing graves are

23

constantly being discovered, and new graves were being created by terrorists and

criminal gangs even before the arrival of ISIS in Iraqi geopolitics (e.g., Schmidt, 2011).

Existing mass graves teams are often called to deal with newer mass graves, as well.

The Iraqi government closely holds the number of known mass graves. In

January 2013, ICMP’s incomplete record of excavations showed 229 known mass

graves sites, of which 130 had been investigated and 44 were scheduled for

investigation. Fifty-four of the 130 sites investigated were found to contain no relevant

material and were cancelled; the rest had varying numbers of human remains, except

for one that was found to contain only clothing. These figures were certainly incomplete.

In 2007, the Regime Crimes Liaison Office’s Mass Graves Investigation Team, on which

the author served, had two sets of records of designated mass grave sites. One,

belonging to the Coalition Provisional Authority (CPA), contained 278 entries; the

RCLO’s own records, which originated with the investigations by the I Marine

Expeditionary Force’s Task Force Justice, under then Major Alvin Schmidt, contained

201 entries (Smith, personal communication, 2012). While some overlap existed and

not all duplicates had been weeded out, it is safe to say that as of 2007 over 300

potential or actual mass grave sites were known in Iraq, and there was a strong

likelihood that the number was over 400. Many Iraqi mass grave sites consist of

complexes containing multiple graves.

Estimates of the number of missing people in Iraq ranges from 300,000 (Human

Rights Watch, 2004) to over one million; approximately 180,000 people are believed to

24

have been killed during the Anfal Campaign. This estimate is likely accurate, given that

the KRG provides payments to the families of those killed in the Anfal.2

Most juveniles in Iraqi mass graves were killed during the Anfal Campaign of

1988, which marked the culmination of the repression of the Iraqi Kurds. Following

forced relocation in the 1970s for control of oil resources, forced relocation of the

Barzani tribe in 1975 for the failed Kurdish Democratic Party revolt, forced relocation for

border security in 1977 and 1978, execution of targeted population segments as a

counter-insurgency method in 1983, the Anfal Campaign designated restricted areas as

essentially free-fire zones. During the Iran-Iraq War, Saddam Hussein had suffered the

irritation of Kurdish fighters working for the Iranians and against the Iraqis; with the end

of the war, he had resources to handle them, and did so with an indiscriminate

onslaught that left regions devastated and whole villages murdered. Anfal graves

typically present as a complex of graves, and tend to be sexually segregated: men in

one grave, women and children in another (e.g., Steele et al., 2005). One women-and-

children grave from Muthanna province contained 114 individuals: 85 were under

eighteen years old, and 79 were under twelve (Steele et al., 2005). The complex

contained nine more graves.

Age Estimation in Iraq – Solutions

Age estimation in Iraq suffers from a lack of population-specific standards.

Accordingly, improvement of age estimation in Iraq requires population-specific

standards for epiphyseal union and for dental mineralization and eruption. As a first

2 In practice, the number of checks issued does not correspond to the number of missing: if a man is missing who had one wife, payouts go to his wife and his parents. If the missing man had more than one wife, the wives get a payment and the parents get nothing. If the missing man is not married, the parents get the payment. If the missing man was unmarried with receive no mother or father, his siblings the payment. Children of martyrs only get payments until they turn eighteen.

25

step, this study will focus on dental mineralization and eruption in Iraq. While Iraqi

medical practice is much less devoted to record-keeping than the United States or

Europe – Iraqi dentists, for example, do not record dental charts and typically discard x-

ray films (Muffeed; Salah, personal communications, 2011) – the rise of digital

radiography has made a large number of detailed panoramic dental radiographs readily

accessible, due to the automatic archiving feature employed by those systems.

Moreover, because Iraqi doctors regularly employ dental age for medicolegal aging of

both living and dead persons, the need for accurate standards is readily conveyed.

The following chapters address the study’s background, structure, and results.

Chapter 2 and Chapter 3 review the literature pertaining to dental eruption and

mineralization and that relating to physical anthropology in Iraq. Chapter 4 details the

study methods. Chapter 5 presents the results, and Chapter 6 reviews the conclusions

for the study.

26

CHAPTER 2 REVIEW OF THE LITERATURE, PART I:

DENTAL AGE ESTIMATION

Background

While the practice of positively identifying individuals through comparison to

known or recorded dental traits extends into antiquity (Cassius Dio 61:32:4, trans. Cary,

1925) cites Nero’s mother Agrippina identifying the beheaded Lollia Paulina by “the

teeth, which had certain peculiarities”), the practice of estimating the ages of individuals

based on teeth is much more recent. Saunders (1837) recognized the stability of dental

development and argued that Britain should adopt dentition over height as an age-

estimation standard. Accordingly, would-be factory workers were judged fit to begin

laboring if their dentition exhibited a single erupted permanent molar, which the law held

meant that they were at least six years old. Müller (1990) states that the Roman army

used eruption of the second molar as a basis for admission, but all citations of Müller’s

claim cite Müller, and none have identified the primary source; moreover, it would be

strange for such a practical age estimation technique to have been entirely lost between

antiquity and 1837.

The date of the first use of dentition and epiphyseal union to estimate the age of

a deceased individual is currently unknown. Brumit and Stimson (2010), citing Amoëdo

(1898), suggest that the first such case is the 1846 examination by a Dr. Recamier of

remains suspected to be Louis-Charles, aka Louis XVII, the ten-year-old “lost dauphin”

of France. Given the nine-year gap between 1837 and 1846, however, it would be

surprising if no other attempt to estimate the age of a deceased child had been made

during that time.

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In the nearly two centuries since, various methods for aging human skeletal

remains, as well as living humans, have flourished; practitioners have incorporated

dentition, bone development, allometry (particularly in the very young)1, tissue

chemistry, and secondary sex characteristics. With regard to dentition in particular, age

estimation has incorporated various aspects of dental morphology, structure, and

composition. Researchers have addressed eruption, mineralization, tooth length

(Cardoso, 2007a), tooth root transparency (Gustafson, 1950; Johanson, 1971; Maples,

1978; Lamendin et al., 1992), formation of cementum (Zender and Hurzeler, 1958, in

Noble, 1974; Gustafson, 1950), secondary dentin formation (Olze et al., 2010),

measurement of open apices of teeth (Cameriere, 2006), tooth wear, surface roughness

(Solheim, 1993), color (Solheim, 1993), and more. A brief review of some of these

methods will provide an idea of the scope and variety of work in the area.

Gustafson (1950) proposed that attrition, periodontitis, secondary dentin,

cementum apposition, root resorption and tooth root transparency were age-related. He

devised a formula to incorporate those features into the estimation of age; doing so

required sectioning the tooth. Each change was assigned a score from 0 to 3; their sum

was inserted into a formula for age estimation. Gustafson’s technique was revised and

modified by several researchers, who revised or eliminated many of his criteria, most

notably Johansen (1971) and Maples (1978); Maples used regression analysis to

conclude that the most effective technique eliminated most of Gustafson’s original

components to focus on secondary dentine and tooth root transparency, weighted for

1 Some creative researchers have adopted a focus on proportion and relative, rather than absolute, allometry; Cameriere et al. (2006), rather than target metric ranges, address age estimation by determining the ratio between chronological age and the total area of the carpal bones and radial and ulnar epiphyses.

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tooth position. Solheim (1993) used Gustafson’s criteria with the exception of root

resorption, and added attention to roughness, color, and sex. Kvaal et al. (1995)

focused on the reduction in pulp cavity volume due to secondary dentin deposition in six

teeth (maxillary incisors and second premolars, mandibular lateral incisor, canine, and

first premolar), employing it as part of a mathematical formula to determine age.

Lamendin (1992) offered a simpler method for single-rooted teeth, based on

multiple regression involving the maximum length of translucency of tooth root and the

degree of periodontosis, as measured by the maximum distance between the junction of

enamel and cementum and the line of soft tissue attachment. In a review, the Lamendin

method was judged more accurate in aging middle adults (aged 41-60 years) than the

Suchey-Brooks pubic symphysis method, the İşcan fourth rib method, or the Lovejoy

auricular surface method (Martrille et al., 2007).

Foti et al. (2003) proposed a complicated regression technique to estimate the

age of individuals based on a combination of eruptions of particular teeth and, in some

instances, tooth germs visible on radiographs, using one of four equations to be

employed variously based on the criteria available. If radiographs were available, one

equation was to be used; another if they were not; a third for the maxilla alone with no

available radiography; a fourth for the mandible alone with no available radiography.

Olze et al. (2010) proposed a four-stage method that described only the degree

of visibility on radiographs of the root pulp of the lower third molars. In the first stage,

both root canals were visible to the tooth apex; in the second, only one was fully visible;

in the third, neither canal was visible to the apex; in the fourth, neither canal was visible

in detail or at all. The method was based on a review of radiographs of 1,198 individuals

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(629 female, 569 male) aged 15-40 years; no control was employed. The method was

limited in scope and was of note, for the authors, primarily because the latter three

stages described individuals over 21 years of age, a distinction between adult and

juvenile offenders in German law: an aging method designed for a binary test

addressing one specific problem.

Mesotten et al. (2002) estimated age based on a regression formula

incorporating the development of the third molars; all individuals in their study, however,

were between 16 and 22, essentially eliminating the possibility of over or under-

estimates. The study employed an abbreviated version of the Gleiser and Hunt scale

designed by Kohler et al. (1994) that ran only between the stages of half completion of

the crown (Cr1/2) and completion of the root apex (Ac).

Dental Eruption and Mineralization

Mineralization and eruption have long been among the most common subjects of

development studies, in part because examination of the dentition by these criteria is so

readily employed, and at its most basic requires neither extraction nor equipment. This

last feature renders dental aging ubiquitous and highly useful, but also poses some

problems for comparing studies. Many eruption studies are clinical in origin, and are

based on in vivo observations made by dentists in the absence of radiographic

equipment. Because gingival eruption and alveolar eruption are not identical, in vivo

observation of the living alone does not necessarily correspond to the development that

would be visible on that of a prepared skeleton (Liversidge and Molleson, 2004);

moreover, as the alveolus continues to remodel after occlusion, alveolar and gingival

eruption should be seen as “a matter of degree, rather than fixed events” (Hillson, 2005:

211). Mineralization, too, may be more advanced on dissection than it appears in

30

radiography (Smith 1991). Even when a model of mineralization is employed, obliquities

of orientation or structural varieties in teeth may also lead to misclassification (Simpson

and Kunos, 1998).

Studies of dental mineralization and eruption are, in practice, studies of

development and timing: the structural growth of teeth, or the age at which tooth crowns

are in a particular physical position with respect to the alveolar and gingival surfaces

before terminating in occlusion. Evaluation of these factors has followed two major

approaches (Demirjian et al., 1973). The first of these is the atlas approach, in which the

examiner compares the individual, skeleton, or radiograph to a series of standard

reference images in order to determine which reference image offers the closest match

(e.g., Gruelich and Pyle, 1959; Ubelaker, 1977). The second is the scoring approach, in

which the examiner examines a prescribed number of features, assigns each to a

category with a numeric value based on defined criteria, and combines the values for

each to yield a total score, which the examiner then compares to a reference chart (e.g.,

Acheson, 1954, 1957; Demirjian et al., 1973, 1976; Tanner et al., 1962).

The Atlas-Based Approach

The earliest approaches to dental aging standards were atlas-based: reference

charts and images, to be compared directly with the item under consideration. Schour

and Massler (1941) is the first major such atlas. It had important precedents in Legros

and Magitot (1880, 1881), Black (1883), Pierce (1884), Brady (1924), and particularly

Kronfeld and Schour (1939) and Kronfeld (1935), whose dental timing tables were

reprinted by Schour and Massler (1941) and then (not always with attribution) a host of

other books (Smith 1991, Smith 2010). Those tables, however, were limited to the most

basic description of mineralization, limiting the stages described to three: initiation,

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crown completion, and root completion. Later efforts to describe mineralization, to put it

succinctly, “differ with regard to the number of stages, the definition of each stage and

the presentation” (Schmeling et al. 2010).

Gleiser and Hunt (1955) developed their mineralization stages from 50 white

American children, divided evenly between male and female, who were part of the

longitudinal study of child growth conducted in Boston by the Harvard School of Public

Health (Stuart et al. 1939). The children had been subject to dental examinations, right

side lateral dental radiographs, and hand/wrist radiographs, at regular intervals since

birth: every three months until reaching 18 months of age, and every six months

between 18 months and 10 years.

In developing the mineralization stages, Gleiser and Hunt (1955) used the first

permanent mandibular molar as a baseline for several reasons, including the timing of

its development, its distortion-minimizing location near the center of a lateral dental

radiograph, and the absence of a deciduous tooth in its place in the dental arcade. For

each child in the study, Gleiser and Hunt (1955) developed an atlas of the first molar

development exhibited by sketching the outline of the permanent mandibular first molar

as it appeared in each radiograph taken during the course of the child’s life. Gleiser and

Hunt (1955) then compared the sketched individual development atlases and “15 stages

of calficication were arbitrarily chosen” (Gleiser and Hunt 1955:255, 282):

I. No calcification

II. Centers of calcification visible

III. Coalescence of centers

IV. Outline of cusps completed

V. 1/2 Crown

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VI. 2/3 Crown

VII. Crown Completed

VIII A. [Root] Cleft minimal

VIII B. [Root] Cleft rapidly enlarging

IX. 1/4 Root

X. 1/3 Root

XI. 1/2 Root

XII. 2/3 Root

XIII. 3/4 Root

XIV. Divergent Root Canal Walls

XV. Convergent Root Canal Walls

Demisch and Wartmann (1956) performed a similar study on 151 children

(81 boys, 70 girls) from the same longitudinal study, focusing on the mandibular

third molar. Their mineralization scheme was patterned after Gleiser and Hunt

(1955), with a few alterations: unable in their tests to reliably distinguish Gleiser

and Hunt’s stage 6 (2/3 of crown completion), from the surrounding stages (1/2 of

crown completion, and crown completion), Demisch and Wartmann (1956)

eliminated the Gleiser and Hunt stage 6, added more detail to the middle stages,

and added definitions of early development centered on the appearance of the

tooth crypt (1956:462):

0. No change in bone density, and no crypt visible.

1. Crypt clearly visible, but no calcification.

2. Calcification of the tips of one to four cusps.

3. Coalescence of two or more centers.

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4. Outline of the cusps completed, calcification proceeding towards the level of the grooves, but the center of the occlusal crown surface may not yet be calcified.

5. Half of the crown completed, calcification up to the largest mesiodistal diameter of the tooth crown, but the entire enamel formation not yet completed.

6. Crown completed, enamel formation completed to enamel-cementum junction.

7. Beginning of root formation.

The stages of Demisch and Wartmann (1956) ended there, as the radiographs

lacked material to develop later stages for the third molars.

Nolla (1960), whose method is covered later, took something of a synthesis

approach with regard to scoring mineralization. Nolla combined the efforts of Demisch

and Wartmann (1956) and Gleiser and Hunt (1955) and eliminated several stages from

the latter. The result was a ten-stage mineralization scheme (El-Yazeed, 2008):

0. Absence of crypt

1. Presence of crypt

2. Initial calcification

3. One third of crown completed

4. Two thirds of crown completed

5. Crown almost completed

6. Crown completed

7. One third of root completed

8. Two thirds of root completed

9. Root almost completed, open apex

10. Apical end of root completed.

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Moorees et al. (1963) returned to the Stuart material, augmented with material

from the longitudinal studies conducted by Dr. Stanley Garn at the Fels Research

Institute. The combined material consisted of 134 children (48 boys, 51 girls) from the

Stuart material and 246 children (136 boys, 110 girls) from the Fels material. Because

many of the children in the Stuart material were not adequately represented by

radiographs taken after ten years of age, due to the onset of World War II, all data on

permanent posterior mandibular dentition came from the Fels children, who had been

radiographed every six months. The analysis produced fourteen stages of tooth

formation (Moorees et al., 1963:1492):

Initial cusp formation (Ci).

Coalescence of cusps (Cco)

Cusp outline complete (Coc)

Crown 1/2 complete (Cr1/2)

Crown 3/4 complete (Cr3/4)

Crown complete (Crc)

Initial root formation (Ri)

Initial cleft formation (Cli)

Root length 1/4 (R1/4)

Root length 1/2 (R1/2)

Root length 3/4 (R3/4)

Root length complete (Rc)

Apex 1/2 closed (A1/2)

Apical closure complete (Ac)

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Females were advanced over males, but not uniformly, and root formation was

observed to exhibit more sexual dimorphism than the crowns. More variety among

development was exhibited in the older ages than in the younger.

The Moorees et al. (1963) scale is the classification of mineralization that has

largely stuck. A numeric version was employed by Anderson et al. (1976) in a cross-

sectional study of pooled sexes that incorporated all teeth. The material consisted of

annual radiographs taken of 232 white children (121 boys, 111 girls) from Burlington,

Canada, as part of a longitudinal study by the Burlington Growth Centre. The results

were aimed at estimating age of attainment, rather than age of appearance; when an

individual’s tooth transitioned between two stages of mineralization from one annual

radiograph to the next, a midpoint of those ages was taken as the age of first

appearance of the new stage (half-way for a one-stage difference, a third of the way for

a two-stage difference).

For physical anthropologists, the most familiar atlas is that of Ubelaker (1978,

1989), usually referenced from its publication in Buikstra and Ubelaker (1994).

Ubelaker’s revisions of Schour and Massler (1941) were based on observations of a

large sample of American Indians; in practice, anthropologists have applied the charts

on individuals representing a host of populations, and have found Ubelaker’s revision

from Buikstra and Ubelaker (1994) to better represent the ages of individuals than the

original Schour and Massler (1941) timings (Smith, 2010). Smith (2010) notes that the

age ranges have varied somewhat among the chart’s various publications.

More recently, Al Qahtani et al. (2010) produced the London Atlas, based on 1)

radiographs of 528 living persons; 2) 50 skeletons from the Spitalfields collection; and 3)

36

126 individuals from the Royal College of Surgeons’ Maurice Stack collection. The live

individuals were ethnically mixed between white and Bangladeshi; the two groups

exhibited no significant difference in ages of tooth development (Liversidge, 2009). The

London Atlas drawings are explicitly based on existing scoring rationales; the scoring of

mineralization follows a modified Moorrees at al. (1963b), and that of alveolar eruption

follows a modification of Bengtston (1935), after Liversidge and Molleson, 2004. The

mineralization stages of AlQahtani are:

Initial cusp formation (Ci)

Coalescence of cusps (Cco)

Cusp outline complete (Coc)

Crown 1/2 complete (Cr1/2)

Crown 3/4 complete (Cr3/4)

Crown complete (Crc)

Initial root formation (Ri)

Root length 1/4 (R1/4)

Root length 1/2 (R1/2)

Root length 3/4 (R3/4)

Root length complete (Rc)

Apex 1/2 closed (A1/2)

Apical closure complete (Ac)

Resorption of teeth likewise follows that of Moorees (1963):

Ac (apex closed with normal PDL width)

Res 1/4 (resorption of apical quarter of the root)

Res 1/2 (resorption of half the root)

Res 3/4 (resorption of three quarters of the root)

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The eruption stages followed by Al Qahtani et al. (2010) are modified from those of Bengston (1935), as follows:

Position 1: when the occlusal or incisal surface is covered entirely by bone

Position 2: when the occlusal or incisal surface breaks through the crest of the alveolar bone

Position 3: when the occlusal or incisal surface is midway between the alveolar bone and the occlusal plane

Position 4: occlusal or incisal surface is in the occlusal plane

This study follows the system of Al Qahtani et al. for comparative purposes.

The Scoring Approach

Some analysts, such as Nolla (1960) and most notably Demirjian et al. (1973)

took a different approach to analysis: the scoring method. Rather than compare an

individual of questioned age to standard reference images depicting individuals of

various ages, Demirijan et al. (1973) proposed an eight-stage model of mineralization,

for use in classifying seven teeth on the left side of the mandible, in order from second

molar to central incisor. To be classified as being in a given Demirjian stage, a tooth

must fulfill the criteria for that stage and for the criteria before it; intermediate cases are

always assigned the lower (younger) stage of development. The scores are classified

as A through H:

A. In both uniradicular and multiradicular teeth, a beginning of calcification is seen at the superior level of the crypt in the form of an inverted cone or cones. There is no fusion of these calcified points.

B. Fusion of the calcified points forms one or several cusps which unite to give a regularly outline occlusal surface.

38

C.

a. Enamel formation is complete at the occlusal surface. Its extension and convergence towards the cervical region is seen.

b. The beginning of a dentinal deposit is seen.

c. The outline of the pulp chamber has a curved shape at the occlusal border.

D.

a. The crown formation is completed down to the cemento-enamel junction.

b. The superior border of the pulp chamber in the uniradicular teeth has a definite curved form, being concave towards the cervica region. The projection of the pulp horns if present, gives an outline shaped like an umbrella top. In molars the pulp chamber has a trapezoidal form.

c. Beginning of root formation is seen in the form of a spicule.

E.

Uniradicular teeth

a. The walls of the pulp chamber now form straight lines, whose continuity is broken by the presence of the pulp horn, which is larger than in the previous stage.

b. The root length is less than the crown height.

Molars

c. Initial formation of the radicular bifurcation is seen in the form of either a calcified point or a semi-lunar shape.

d. The root length is still less than the crown height.

Each stage of each tooth has a corresponding score, determined by reference to

a table. Summing the scores for all teeth yields the maturity score, which then

corresponds to a particular age given by a chart based on analysis of the population in

question.

39

The original study by Demirjian et al. (1973) was based on panoramic

radiographs of 2,928 children (1482 girls, 1446 boys) ranging in age from two to 20

years. It treated males and females separately, as the Demirjian age estimate for a

particular radiograph will vary depending on whether the subject is male or female.

Later revision included a version of the Demirjian approach that worked for four teeth as

well as a regression formula approach (Demirjian and Goldstein 1976, Demirjian 1986,

Panchbhai 2011).

One intent of the scoring approach in Demirjian is to reduce interobserver error,

as Morrees stages have been criticized as being too numerous, and sometimes

challenging to differentiate (Olze et al. 2005, Cardoso 2007, Schmeling 2010); McVeigh

(1999) published a method for converting Moorees stages to Demirjian stages, and Al-

Qahtani et al. (2010) eliminated the initial cleft appearance stage (Table 2-1).

Table 2-1. Correspondence between Moorees (1963) stages, Demirjian (1973) stages, and Al-Qahtani et al. (2010) (after McVeigh, 1999).

Demirjian Moorees AlQahtani

Stage A Ci, Coc Ci, Coc Stage B Cco Cco Stage C Cr1/2, Cr3/4 Cr1/2, Cr3/4 Stage D Crc, Ri Crc, Ri Stage E Cli, R1/4 R1/4 Stage F R1/2, R3/4 R1/2, R3/4 Stage G Rc, A1/2 Rc, A1/2 Stage H Ac Ac

Another advantage of the Demirjian technique and other scoring methods that

has not been widely noted, but becomes immediately apparent when one is working

with a large dataset, is that once the individual features are scored software can easily

be used to estimate the age of every individual in the dataset, whereas without custom

scripting this degree of automation cannot be done with the atlas method. At the same

40

time, Demirjian himself noted that a weakness of the scoring approach is that it poses

challenges in handling the problem of agenesis or loss of teeth (Demirjian et al.,

1973:216). It also tends to underestimate age (Jayaraman et al., 2013).

Interestingly, while the atlas-based techniques of Ubelaker, Schour and Massler,

and Al-Qatani are the most commonly used by the American forensic community,

papers addressing scoring approaches are more common in Europe, Asia, and India.

Bérgamo et al. (2016) conducted a PubMed review of dental age estimation papers

published in English from 2012-2016 and found that of fifty-eight papers from a

multitude of countries, most of them outside the Anglosphere, fully thirty-three focused

in whole or in part on the Demirjian method.

Variability and Regional Studies

Dentition has long viewed as being more stable than skeletal features as

allometry and epiphyseal union (Cardoso, 2007b; Ubelaker, 1987; Ubelaker, 1989). In

particular, within the broad subject of dentition, mineralization is viewed as more

resistant to environmental insult than eruption (Gleiser and Hunt, 1955; Demisch and

Wartmann, 1956; Noble, 1974; Smith, 1991). Nonetheless, variability in the eruption and

mineralization of human dentition is an ongoing concern of age estimation research,

with particular focus on population and individual genetic variation, living conditions, and

study methodology (Alvesalo, 1997; Heuze, 2008). The relationship between eruption

and mineralization itself is likewise variable; tooth eruption typically begins when the

root reaches 3/4 its final length (Gron, 1962), but this differs, with mandibular canines

and second molars erupting at greater root length, while mandibular central incisors and

first molars erupt with less root length (Suri et al. 2004).

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The clinical literature notes that dental development and failure to erupt may be

affected by a number of factors: physical obstruction, dysplasias, disease, nutritional

factors, hormonal factors, low birth weight, tobacco smoke, developmental and genetic

disorders, and drug side effects (Suri et al. 2004, Almonaitiene et al. 2010). On a

genetic level, multiple genes effect timing of dental development and numerous other

aspects of dentition including aspects of tooth morphology, agenesis, malocclusions,

caries susceptibility, even aggressive periodontitis (Ahmad et al., 2006; Tyagi et al.,

2008). Based on a study of 5,104 Danish National Birth Cohort women, Geller et al.

(2011) identified four loci associated with permanent tooth eruption in children:

rs12424086 (chromosome 12q14.3), rs4491709 (chromosome 2q35), rs2281845

(chromosome 1q32.1), and rs7924176 (chromosome 10q22.2); the latter was also

associated in the number of deciduous teeth at 15 months old, and the time till eruption

of first tooth. Children aged 10-12 with multiple alleles associated with delayed eruption

had an average of 3.5 fewer permanent teeth (18.5 mean, SD 4.5 for individuals with 6-

8 alleles versus 22 mean, SD 4.2 for individuals with zero or one). There were no signs

of different results among sexes, but few males were in the study; other studies have

long suggested links between the X and Y chromosomes and aspects of dental

development, with the Y chromosome being linked to tooth enamel and dentin and the

X chromosome linked to enamel formation (Alvesalo, 1997).

Dentition is not unaffected by life events, some of which may be detected on a

micro-level (Smith and Tafforeau, 2008). Confirming this in humans is challenging, as

mapping dental enamel to human life events is unlikely without a combination of an

obsessive dentist and totalitarian surveillance, but it has been observed in zoo animals;

42

a captive gorilla exhibited lines in tooth enamel associated with injury, medical care, and

being moved from one habitat to another (Schwartz et al., 2006). Lampl and Johnson

(1996) evaluated a Mexican sample of individuals known to have childhood stressors

affecting growth: environmental stress, chronic malnutrition, in a population with

moderate to high levels of disease. In that population, children below the age of nine

appeared approximately half a year younger in the Demirjian age range estimate. Hand-

wrist assessments of the same individuals, after Greulich-Pyle, underestimated the

children’s age to a much greater degree, by well over two years in over half of the

cases. In reviews of an unstressed population, Hunt and Gleiser (1955) found much

greater agreement between dental and skeletal age, providing the proper sex

assignment was used; the same authors noted the greater resistance of dental

development to delay (Gleiser and Hunt, 1955:274):

The characteristic finding in tracing ‘bone age’ and ‘dental age’ serially on the same child is that severe and prolonged delays in osseous maturation, as shown when the ‘least mature centers” fail to progress in their calcification in the hand, can also be seen in the tooth, as shown in figure 2. In general, however, the delays in dental calcification are less prolonged than those of the wrist and hand.

Gleiser and Hunt (1955) were also the first to appreciate the variability of

emergence compared to mineralization, noting that “on an individual basis, the

calcification of a tooth may be a more meaningful indicator of somatic maturation than is

its clinical emergence” (1955:269). This observation remains true. An example of the

human variety in eruption may be demonstrated by a glance at eruption sequence. The

most common deciduous dental eruption sequence in humans is i1-i1-i2-i2-m1-m1-c1-c1-

m2-m2, but, as a function of eruption timing, this sequence may vary considerably

among populations (Holman, 1998): In two New Guinea populations the maxillary

43

second molars erupt before the mandibular (Malcolm, 1973; Friedlander and Bailit,

1969); a Tunisian population exhibited similar reversal, but with the first molars

(Boutourline and Tesi, 1972); an Indian population, with the canines (Kaur and Singh,

1992); a Korean, with both first and second molars (Yun, 1957). Broadly speaking,

African-Americans develop earlier than European-Americans, and females develop

earlier than males; African-Americans are also more sexually dimorphic than European-

Americans (Nanda, 1960; Harris, 1990). Females develop earlier than males (Garn et

al., 1959, Lysell et al., 1964; Hurme, 1957 in Noble, 1964). Holman and Jones (1998,

2003) reported males may lead anterior dentition, while females may lead in

development of the posterior dentition.

Nor is such population variability limited to humans; chimpanzees, like humans,

show variability within their dental development, though they show a different eruption

sequence, with molars developing in advance of anterior teeth (Dean and Wood, 1981;

Anemone et al., 1996). Sex differences have been reported in the chimpanzee dentition

(Kuykendall, 1996) with considerable variation reported among orangutans (Winkler et

al. 1996).2

Efforts to collate these disparate population findings in one location are

surprisingly rare, (Olze et al. (2006) and Jarayman (2013) being some notable

exceptions). One challenge is the variety of scoring and analytical methodologies

(Smith, 1991); Simpson and Kunos (1998:497), using their own scoring standard,

compared with multiple other studies and found numerous differences, noting “it is

2 Winkler et al. (1996:215) also note that in some populations, humans exhibit incisor root development at the time of molar emergence, a commonality not reported in the great apes, and that this difference is also reflected in the differences “reported between robust and gracile australopithecines” (though the humans follow the robust pattern).

44

difficult to resolve whether these differences are a product of actual biological and

ecological differences or method of applying the standard.”

Anthropologists are more likely to compare methods against one another (e.g.,

Saunders et al. 1993). Mapes et al. (2006) compared the methods of Demirjian (1973,

1976), Willems et al. (2001), Nolla (1960), and Haavikko (1974), and found Willems to

be the most accurate, Demirjian next, Haavikko for ages 3-13.99 ages, Haavikko for all

ages, and Nolla least. Under Haavikko (1974), the use of a single molar or premolar to

estimate age was more accurate than developing an overall average for all teeth.

Brkic et al. (2006) compared the methods of Bang and Ramm (1970), Kvaal and

Solheim (1989), and Johanson (1971) in aging 160 extracted teeth from individuals of

known age and sex from the Croatian population, and reported Johanson’s proved most

effective. Tompkins (1996) compared radiographs of prehistoric Native Americans from

museum collections representing California, the Southwest, and Kentucky, with

radiographs representing multiple life points of white French Canadians from a

longitudinal study, and dental radiographs of black Africans from Botswana and South

Africa. He observed no difference in the premolar mineralization, but noted the Africans

and Native Americans appeared advanced over the French Canadians with regard to

the second and third molars.

Secular change has been noted in several populations. In Denmark, Parner et al.

(2001) found “a small but significant increase in mean eruption times for both sexes and

almost all teeth,” larger for females than males, between birth cohorts of 1969 and 1982

(Parner et al., 2001:425). In France, Rousset et al. (2003) found a trend for later

45

eruption of maxillary premolars coupled with earlier emergence of permanent second

molars.

Most of the Near and Middle East have lagged in analysis, for cultural and

logistical reasons to be addressed in the next chapter. A notable exception is Turkey.

The legacy of Ataturk meant for that Turkey, more secular than the Arab Muslim

nations, has been able to produce scholarship in physical anthropology, and in the past

ten years (in part likely due to increasing refugee streams) has seen research in age

estimation. Uysal et al. (2004) evaluated skeletal and dental age, comparing hand-wrist

radiographs and panoramic dentition, with the latter scored by Demirjian standards,

reporting that the “at the same skeletal maturity stage, males had a more advanced

trend in tooth calcification, and the opposite pattern was present in females;”

unfortunately, the results were not reported in detail. Kirzioglu and Ceyhan (2012)

assessed 425 healthy children aged between 7 and 13 years by the methods of Nolla

(1960), Haavikko (1974), and Demirjian et al. (1973). They reported that Nolla and

Haavikko underestimated age, while Demirjian overestimated age in the Turkish

population; of the three, Haavikko was the most accurate. In eastern Anatolia, by

contrast, Karatas et al. (2013) reported that a review of 832 individuals (424 males, 408

females) found males to mature faster than females and the Demirjian technique to

underestimate age, more so in males than in females. Celik et al. (2014) argued, based

on a review of 488 boys and 44 girls aged between 4 and 18, that the Demirjian

standard was not suitable for the Turkish population, as it underestimated younger

individuals and overestimated older ones. Karadayi et al. (2014) developed and

validated a dental atlas for Turkey, but the original study was not available to this writer.

46

Iraq is a very different story. Despite one of the richest cultural histories in the

world, its physical anthropology has been effectively handicapped by cultural, political,

and logistical concerns: not only for the development of Iraq’s own physical

anthropology, but for work by outside researchers.

47

CHAPTER 3 REVIEW OF THE LITERATURE, PART II: PHYSICAL ANTHROPOLOGY OF IRAQ

Beginnings of Physical Anthropology in Iraq

The major figure in the physical anthropology of Iraq was Henry Field (1902-

1986). Like many early American anthropologists, Field came from a wealthy family –

his great-uncle Marshall Field was the founder of a famous department store in

Chicago, Illinois, and had given one million dollars to support what was named in

Marshall’s honor as the Field Museum. Henry Field served as the museum’s curator of

physical anthropology, and like most physical anthropologists of his generation he was

very interested in the racial makeup of humans. The anthropology of those days

employed typologies and techniques not used today, many of which are seen at best as

very unfashionable by present-day Western physical anthropologists. Its attitudes were

often bristling with Eurocentrist or imperialist thought, and Field (1936:49) was no

exception:

What is the racial position of the Arab? How is the Arab of Iraq related to the peoples of Asia, Africa and Europe? These problems have been little studied due to the fact that the Arab remained aloof and independent of European domination until the World War.

Field was a typical physical anthropologist of his day: that is to say, he put

considerable effort into measuring living people in an attempt to understand their

biological distance. Field and his contemporaries in the region, including Kappers

(1930), Krischner and Krischner (1932), and Shanklin and Izzeddin (1937), following in

the footsteps of predecessors including Chantre (1895) and Luschan (1911), measured

a variety of peoples (including Arabs, Armenians, and Kurds) and of nationalities

(including Egyptians, Iraqis, Syrians and Lebanese). Their subjects were primarily men,

but some female researchers were able to measure women; often, foreign

48

anthropologists collaborated with local researchers. Some researchers, such as Dr.

B.H. Rassam and Winifred Smeaton, who measured Iraqis in the Royal Hospital in

Baghdad, did not themselves publish but shared their data with others. For the most

part, the researchers followed similar procedures to one another: they asked to

measure hospital patients, soldiers, laborers, students; they recorded standing and

sitting heights, body and facial proportions, and size and shape of the head.

“Observations were also recorded on the hair, eyes, eyebrows, nose, teeth, ears,

scapulae, chest, musculature, health and pathological characters” (Field, 1936:53).

Unlike modern physical anthropologists, Field and his contemporaries paid

relatively little attention to skeletal biology. What analysis of Iraqi skeletal material there

was came out of archaeology. Skeletal remains found during Sir Leonard Woolley’s

1922-1934 excavations of Ur and al-’Ubaid were sent to England for analysis by Sir

Arthur Keith (1927, 1934). These remains consisted of individuals from Ubaid, Pre-

Sargonic and Dynasty of Akkad periods (Postgate, 1992; Molleson and Hodgson,

2003).

While Keith had lived in Asia and knew about skeletal population differences,

particularly with regard to cranial shape, his estimates of stature for the skeletons of Ur

were based on research of English bones. The fascination with racial differences above

all else persisted; Buxton and Rice (1931), for example, who analyzed skeletal remains

excavated from Kish between 1923 and 1926, wrote an analysis that focused very

heavily on the ethnic grouping of the crania, but did not even attempt to evaluate or

enumerate the remains by sex.

49

Over the years, “traditional morphological studies of the populations of Southwest

Asia . . . attempted to trace migrations and reconstruct racial histories of the area”

(Rathbun, 1984). Sołtysiak (2008) writes a good account of the major debates of the

area of study; its final results are admirably summed up by Ogihara et al. (2009:9):

Based on cephalic index (maximum head breadth/maximum head length), these studies have suggested that inhabitants in southern Mesopotamia have been basically dolichocranic and largely unaltered over a period of thousands of years to the present day (Keith, 1927; Ehrich, 1939; Swindler, 1956).

In short, southern Iraqis have consistently had heads that are longer than they are wide.

Population Standards: Solutions

The challenge for a modern researcher, in the absence of Middle Eastern

population standards, lies in finding an appropriate approach to use to evaluate

skeletons from the region. A complicating factor is the variation of standards’ accuracy

from one population to the next is that the long history of the Middle East means that

archaeology confined to one country will still effectively yield multiple populations,

simply in changes from one time period to the next, as is the case with body proportions

in ancient Egyptians (Zakrzewski, 2003).

In general, researchers studying Middle Eastern skeletal material have followed

one of two approaches: either they have used Western standards to describe/evaluate

Middle Eastern populations, with caveats (e.g., Robins and Schute, 1986; Sołtysiak,

2008; Molleson, 2009), or they have developed the information accessible from known

Middle Eastern populations, usually living people (e.g., Hattab et al., 1996; Ayoub et al.,

2009; Kharoshah et al., 2010). These two avenues of research, rarely intersecting, are

in large part the story of physical anthropology in the region.

50

Robins and Schute (1986), for example, faced the problem of having to apply

stature estimation techniques based on white and black Americans to ancient

Egyptians. Their solution was to compare body proportions; as ancient Egyptian body

proportions are closer to American blacks, the authors used American black standards

for stature estimates. Raxter et al. (2007) and (2008) took another approach by

measuring the component segments of ancient Egyptian skeletons that contribute to

height, and using these results to derive stature estimation formulae.

Iraq-specific physical anthropology has been largely limited. Ogihara, Makishima,

and Ishida (2009:9) note that

Morphological studies on Mesopotamian human remains [as opposed to living people] are confined to those excavated from al-Ubaid (c. 4000 BC) (Keith, 1927), Ur (1900–1700 BC) (Keith, 1927), Kish (c. 3000 BC) (Buxton and Rice, 1931; Penniman, 1934), and Nippur (c. 900–500 BC and 9th century AD) (Swindler, 1956) in southern Mesopotamia, and from Yorgan Tepa (c. 3rd century AD) (Ehrich, 1939) in northern Mesopotamia.

Sołtysiak (2008) provides a more detailed review which adds a number of smaller

sites, but notes that “…there are many European countries where more reports on

human remains from archaeological sites are written each year than the total number

[92] of all papers from the whole history of excavations in Mesopotamia.” (Sołtysiak,

2008:152).

Aside from dental emergence studies (detailed below) published by Baghdady

and Ghose (1981) and Ghose and Baghdady (1981), only one Iraq-specific population

standard is known to this author. Between 1978 and 1980, Japanese archaeologists

from Kokushikan University excavated the Hamrin Basin. By measuring the skeletons of

52 ancient Iraqi individuals (25 male, 27 female), Wada (1994) developed a discriminant

function to determine sex based on the radius.

51

Iraq is not unique in its paucity of population-specific data. Efforts to develop

population standards for the Middle East as a whole have been relatively few, in part

because of the lack of local interest and in part because cultural norms create extreme

difficulties in creating research skeletal collections.5 While medical and dental literature

may contain some information that would be of use in evaluating population standards,

often medical and anthropological landmarks are not directly comparable (e.g., Igbigbi

et al., 2003), or the data are not presented in a way that would permit the necessary

information to be gleaned (e.g., Al-Jasser (2005), which discusses Saudi dental

morphology, but does not break it down in a manner that permits comparison with other

studies).

Egypt and Lebanon are comparatively more relaxed, but even there the forensic

communities have attempted to circumvent this difficulty by using medical imaging to

develop and evaluate some metrics for their respective populations. For example, the

angle of the mandible is sexually dimorphic in Western populations, and is often

recommended as an item worth evaluating in less examined populations. Ayoub et al.

(2009) conducted a radiographic survey of 83 young Lebanese (40 males and 43

females, aged between 17 and 26 years), and found no statistically significant sexual

dimorphism in the mandibular angle. Kharoshah et al. (2010) performed spiral CT scan

survey on 330 Egyptians (165 males and 165 females) and found significant

differences, which were approximately 84% accurate in classification. The mean

5 The author encountered an unexpected ramification of this problem when serving as consultant for the Baghdad Medicolegal Institute on cases involving extreme decomposition: the typical hot/warm water maceration procedure was unthinkable to the Baghdadis, who feared for their physical safety if rumors were to escape that they were treating human remains in such a manner.

52

Egyptian angle was greater than the mean Lebanese angle reported by Ayoub et al.

(2009).

Much of the work on population standards in the Middle East that has been

produced has been done only in the last several years, and owes much to the

increasing availability of digital radiography, which requires no bulky physical storage for

images, can be duplicated at no cost, automatically archives and systemizes, and is

readily searchable. The advent of digital radiography enables even more conservative

studies to perform some population standard assessment, using data that was literally

unavailable only a few years ago.

Middle East

The utility of panoramic digital radiography has, by greatly lowering costs of

individual radiographs and facilitating storage, acted to facilitate a number of studies

involving dental mineralization. The research has swelled, in turn, due to the refugee

crisis in the region, where aging undocumented juveniles has become a growing

problem. What was a trickle of research has become a flood.

Al-Jasser (2003) examined Saudi children aged 4-40 months, and reported a

“slightly delayed eruption of primary teeth” in comparison to European and American

populations. Alshrihri et al. (2015) reported that 65% of Saudi individuals aged by the

London Atlas were within one year of chronological age, with results not ideal for the

Saudi population but better than the Ubelaker and Schour and Massler standards.

Bagherian and Sadeghi (2011) tested the Demirjian method on 519 Iranian children

(264 boys, 255 girls) aged 3.5 to 13.5 years. Age was over estimated by 0.15 years in

boys and 0.21 years in girls. Overestimation was more common in younger children, but

underestimation was common in older age groups. Bagherpour et al. (2010) likewise

53

found Demirjian overestimation in Iranians, and Baghdadi (2013, 2014) in Saudis. Abou

el-Yazid et al. (2008) studied panoramic radiographs (Nolla’s technique) of 378

Egyptians (males and females) aged 6-15 to develop Demirjian charts for Egyptians.

Demirjian standards have been adapted for Kuwait (Qudeimat and Behbehani, 2009)

and the United Arab Emirates has found utility in the Willems et al. (2001) update of

Demirjian.

In this flurry of activity, Iraq remains behind. To the knowledge of this researcher,

Iraq has had only two studies performed involving local dental standards, and those

concurrently by the same parties: Ghose and Baghdady (1981) and Baghdady and

Ghose (1981). Baghdady and Ghose (1981) examined 1017 Iraqi children aged from 1

to 40 months, finding no differences between left and right sides, but earlier eruption in

males, with the exception of the maxillary central incisors and mandibular second

molars. Ghose and Baghdady (1981) studied the eruption of permanent teeth in 2,843

Iraqi children aged 4-15 years, finding in this group that females were advanced over

males dentally by approximately three months. All examinations were intraoral, visual,

and limited to emergence, and focused only on the Arabs of southern Iraq; to date, no

studies have addressed dental age for the Iraqi Kurds. It is this lack that this study aims

to correct.

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CHAPTER 4 METHODS

Permissions and IRB Approval

Research in Iraq is complicated by the country’s poor security, but also by a lack

of integration with the international research community. In Iraq, the concept of an IRB

is almost entirely unknown. In preparing for the IRB submission for this project, the

University of Florida IRB conducted a search for IRBs in Iraq, and found one at the

University of Tikrit, in Saladin province. Tikrit is the hometown of the late Iraqi dictator

Saddam Hussein, and is not a safe location for travel for many Iraqis, let alone a foreign

researcher. The IRB was presumably founded for a specific U.S. government grant.

The University of Florida IRB advised that detailed oversight would not be

required if the author received deidentified radiographs and corresponding demographic

information collected by a local clinic in the course of normal operations. Requesting

this records review was less hazardous than a trip to Tikrit, but proved culturally jarring

as this author discovered that Iraq has no patient privacy laws whatsoever. The very

concept of the importance of patient confidentiality was initially puzzling for many Iraqi

colleagues, but they were graciously willing to accommodate what was, to them, a

culturally strange request.

Following several meetings with the Ministry of Health for the Kurdistan Regional

Government, the matter was referred to the attention of the Minister of Health, Dr. Taher

A. Hawramy, who gave authorization and a letter of support to the project. With the

Minister’s authorization, Dr. Hussein Mohammed Ali of the Khanzad Health Center, a

busy public dental clinic run by the Ministry of Health, was able to provide a total of

1,440 anonymized panoramic radiographs collected during the course of routine dental

55

examinations. Each radiograph was identifiable only by the randomly-assigned record

number in its filename; the same randomly-assigned record number was used to link

the radiograph to the corresponding record of the anonymous individual’s age, sex, and

ethnicity.

Dataset Preparation and Database Construction

A Microsoft Excel spreadsheet was used to review the list of radiographs and

sort them by age and sex. The radiographs received represented 754 females and 686

males ranging in age from three to twenty-five years. One hundred males and one

hundred females ranging in age from five to twenty-five years were removed to serve as

a control; two new Excel sheets were used to document the contents of the two

datasets (experimental and control). As only a very few individuals aged three and four

were represented in the experimental dataset (one aged three, five aged four), no

individuals of those ages were included in the control. The list of individual numbers was

checked against the images and against their own entries for missing data. Individuals

with incomplete data, or images that were corrupt or had not been transferred, were

removed from their respective datasets. The resulting datasets consisted of 1,222

individuals (576 male, 646 female) in the experimental dataset and 195 individuals (99

male, 96 female) in the control (Table 4-1).

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Table 4-1. Numbers of individuals in experimental and control datasets. In Experimental Dataset In Control Dataset Age Male Female Total Male Female Total

3 1 0 1 0 0 0 4 3 2 5 0 0 0 5 6 5 11 0 2 2 6 10 6 16 2 4 6 7 18 16 34 3 9 12 8 26 23 49 7 8 15 9 20 26 46 7 12 19 10 39 33 72 7 11 18 11 50 33 83 7 4 11 12 45 29 74 10 5 15 13 25 30 55 4 4 8 14 17 13 30 2 3 5 15 11 11 22 2 5 7 16 9 21 30 2 5 7 17 15 14 29 2 3 5 18 15 18 33 2 3 5 19 23 40 63 5 3 8 20 22 42 64 6 3 9 21 41 52 93 5 3 8 22 50 63 113 5 2 7 23 51 73 124 7 3 10 24 45 56 101 7 2 9 25 34 40 74 7 2 9 TOTAL 576 646 1222 99 96 195

Two separate Filemaker Pro 13 databases with nearly identical structure were

constructed, one for analysis of each dataset. To maintain blindness during scoring

while allowing the possibility of error-checking in the event of an importing malfunction,

each individual’s data had two options for viewing: the scoring view and the chart view.

The scoring view was used for scoring individual teeth, and displayed the record

number, the radiograph, the filename of the radiograph required and that of the

radiograph displayed (to verify the correct radiograph was shown), the original row

number in the relevant Excel spreadsheet, and the scoring for each tooth. The chart

view was not used during the scoring process to avoid bias, but was built into the

57

database in the event that a software error required double-checking, or if access to all

data would be needed during later review (Figure 4-1).

Figure 4-1. Experimental database, scoring view, showing dropdown menu.

The scoring view displayed the individual’s number, birth year, age, sex,

ethnicity, city, original row, image path of the radiograph and the file name of the

expected radiograph, and below these the dental chart. The only difference between the

experimental and control datasets was the addition of a separate data field in the control

dataset for the purpose of entering the estimated age of the individual based on the

radiograph (Figure 4-2).

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Figure 4-2. Control database, chart view.

The dental chart used in the databases was laid out as a series of data entry

fields. The position of each tooth’s data entry fields in the chart corresponded with the

position of that tooth in the radiograph. Each tooth had two data entry fields: one to

document degree of mineralization, one to document degree of eruption. Each data

entry field in the dental chart was set up as a dropdown menu, for ease of work and to

prevent the possibility of typographical error. For ease of comparison, the dropdown

menus and scoring standards used were the modified Moorees and Bengston scales,

as used by AlQahtani (2009) and AlQahtani et al. (2010), for mineralization and

eruption, respectively. The dropdown options for mineralization for each tooth were

Absent, Ci, Cco, Coc, Cr1/2, Cr3/4, Crc, Ri, R1/4, R1/2, R3/4, Rc, A1/2, Ac, and

Unobservable. The dropdown options for eruption stages for each tooth were Absent, 1,

59

2, 3, 4, and Unobservable. The definitions for each stage were those of AlQahtani

(2009) and AlQahtani et al. (2010).

Analysis of Findings and Standard Construction

When each individual in the experimental database had been scored, the

database records were exported to Microsoft Excel for review. To facilitate analysis, the

mineralization and eruption stages were converted to numbers. These values

corresponded to the modified Moorees and Bengston scales used by AlQahtani (2009)

and AlQahtani et al. (2010). The numbers corresponding to the modified Moorees scale

ran from 1 to 18, while those corresponding to the modified Bengston scale ran from 0

to 5. Absent teeth were indicated by a number at either the lowest end of the scale (1

for Moorees, 0 for Bengston), to indicate that the tooth had either not formed, or the

highest (18 for Moorees, 5 for Bengston), to indicate that the tooth had been lost. In the

conversion, absent permanent teeth in youthful individuals were generally assumed to

not have formed, while deciduous teeth were assumed to have been lost by older

individuals (Table 4-2).

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Table 4-2. Mineralization and eruption stages, with corresponding numeric values. Moorrees Stage Numeric Value Bengston Stage Numeric Value

Absent 1 Absent 0 Ci 2 1 1 Cco 3 2 2 Coc 4 3 3 Cr1/2 5 4 4 Cr3/4 6 Absent 5 Crc 7 Ri 8 R1/4 9 R1/2 10 R3/4 11 Rc 12 A1/2 13 Ac 14 Res1/4 15 Res1/2 16 Res3/4 17 Absent 18

The numeric conversion permitted automation of the calculation of the mean,

median, variance, and standard deviation for male, female, and pooled groups of both

sexes for each tooth, and the graphing of results for each tooth and the overall dentition.

To facilitate comparison with Ubelaker (1977, 1994) and AlQahtani (2009) and

AlQahtani et al. (2010), the median of the pooled right dentition was used to develop

this project’s standard for Kurdish eruption and mineralization.

Checking against Control

Using the control database, each individual in the control was examined, their

teeth scored, and their age estimated according to the Kurdish standard. When

complete, the results were exported to an Excel spreadsheet and the age estimation

could be compared to the actual age of the individual in question.

Checking the efficacy of the Kurdish standard against the existing atlas

standards of Ubelaker and AlQahtani posed challenges. The weakness of the atlas

61

approach is that without custom scripting, comparisons of dental charts and standards

cannot readily be automated. To speed the workflow and facilitate direct comparison of

the three atlas standards, a scoring approach was developed. The numeric value of

each tooth’s mineralization was added to the numeric value of its eruption stage; the

sum of the values of all teeth provided the overall score for the individual. The total

score for each individual was compared to the total score thus attained for each stage of

the AlQahtani, Ubelaker, and Kurdish standards, and the age under each standard

estimated. Each of these was compared to each other, as well as the age estimated by

the atlas approach using the Kurdish standard.

Additionally, descriptive statistics were calculated for each tooth at every age for

both genders, as well as pooled sexes. Two-tailed comparison of means was employed

for each tooth to determine whether difference was significant at the p=.05 level at a

given age for the mineralization and eruption stages, contrasting males vs. females, and

right side vs. left side.

These comparisons enabled the assessment of relative development among the

various standards. This assessment included such features as how quickly the teeth of

a typical individual from a given population undergo mineralization or eruption and the

rate of the transition from early to late stages of each process, as well as the shift from

deciduous to permanent dentition. Differences in standards would affect age estimates;

for example, if one standard appeared developmentally advanced (exhibiting dentition

consistent with an older chronological age) over a second standard at a particular age,

using the first standard would result in a younger age estimate than would using the

other. Likewise, a standard that appeared developmentally delayed (exhibiting dentition

62

consistent with a younger chronological age) relative to another standard would yield a

younger age estimate.

A Note on Error

Due to normal human variation, as well as any external factors affecting

development, any age estimation study is necessarily inexact. Individuals may not

exactly resemble the expected degree of development for their given age. Some may

appear younger, some older. For this reason, age estimates are typically stated as a

range, rather than as a single date.

Ubelaker’s atlas (Buikstra and Ubelaker 1994) depicts twenty-one reference

images, each of which corresponds to a given age but carries a plus-or-minus,

effectively stating a mean, minimum, and maximum for each stage of development

(Table 4-3).

Table 4-3. Ages and corresponding error ranges in Ubelaker standard. Age Error range

5 months in utero ± 2 months 7 months in utero ± 2 months Birth ± 2 months 6 months ± 3 months 9 months ± 3 months 1 year ± 4 months 18 months ± 6 months 2 years ± 8 months 3 years ± 12 months 4 years ± 12 months 5 years ± 16 months 6 years ± 24 months 7 years ± 24 months 8 years ± 24 months 9 years ± 24 months 10 years ± 30 months 11 years ± 30 months 12 years ± 30 months 15 years ± 36 months 21 years [no range given] 35 years [no range given]

63

While these plus-or-minus factors range from two months for the very youngest

to 36 months at age 15, “an individual estimate may be off as much as five years,

especially in the older categories” (Ubelaker, 1989:64). Although Ubelaker (1989)

provides references to the sources of data, including mean stages of development as

addressed in Moorrees et al. (1963), he does not detail how the plus-or-minus factors

for the chart were calculated. Citations of Ubelaker’s atlas usually reprint it as a chart,

without reference to the method of its construction.

The London Atlas, as published by AlQahtani (2009) and AlQahtani et al. (2010),

presents twenty-three full dentition reference images for individuals aged 30 weeks in

utero to 15.5 years and an additional eight reference images of the third molars for

individuals aged 16 to 23 years. No error ranges are provided for any stage, owing to

the nature of the construction of the atlas. The London Atlas is developed using the

median, rather than mean, stage of development of mineralization and eruption for teeth

at a given age. No error ranges are provided, as this approach does not facilitate the

statistical calculation of error, nor is there a test against a control group.

In order to facilitate a direct comparison with the London Atlas, its methodology

was used to build the Kurdish standard. As in the case of the London Atlas, this

approach did not permit estimation of error or quantification of confidence in the age

estimate. While a detailed assessment of expected error remains to be addressed

before publication, the use of a control to validate the Kurdish standard alongside the

London Atlas and Ubelaker’s standard provides insight into the limits of each standard,

and the degree to which each is inaccurate in assessing the age of the control.

64

CHAPTER 5 RESULTS

Organization of this Chapter

This chapter details, in three major sections, the results of the analysis of the

experimental dataset as detailed in Chapter 4. The first section details the results of the

experimental group. The second addresses the construction of the new Kurdish

standard for age estimation. The third validates the Kurdish standard against the control

sample, and compares the effectiveness of the Kurdish standard to those of the existing

atlases by Ubelaker (Buikstra and Ubelaker 1994) and AlQahtani (2009) and AlQahtani

et al. (2010).

Experimental Group Results

This section describes the experimental group results for each tooth in

deciduous and permanent dentition. It begins with an overview of deciduous maxillary,

then mandibular dentition, with comparison of left and right sides, and males, females,

and pooled sexes. The deciduous mandibular, and permanent maxillary and mandibular

dentition, follows the same pattern. The section concludes with overall analysis of the

deciduous and permanent maxillary and mandibular dentition for males, females, and

pooled sexes.

As the younger ages are poorly represented in the experimental dataset, they

are documented for interest but caution is recommended. Only one three-year-old

individual and five four-year-olds are present. Eleven five-year-olds and sixteen

individuals aged six are represented.

65

Dentition Overview

As is to be expected from experience in other populations, the mineralization and

eruption of the dentition of the people of Iraqi Kurdistan follows a consistent pattern.

Comparison of the mineralization and eruption scores of left and right sides, male,

female, and pooled sexes, shows notable consistency, particularly in the deciduous

dentition. As should be expected given the longer period of development, the

permanent dentition exhibits more variety in development, and more statistically

significant differences than are seen than among the deciduous dentition. This may be

seen most readily by a glance over the plotted means of each tooth (Figures 5-1

through 5-52).

Figure 5-1. Mean stages of mineralization, first maxillary deciduous incisor.

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Figure 5-2. Mean stages of eruption, first maxillary deciduous incisor.

Figure 5-3. Mean stages of mineralization, second maxillary deciduous incisor.

67

Figure 5-4. Mean stages of eruption, second maxillary deciduous incisor.

Figure 5-5. Mean stages of mineralization, maxillary deciduous canine.

68

Figure 5-6. Mean stages of eruption, maxillary deciduous canine.

Figure 5-7. Mean stages of mineralization, maxillary deciduous first molar.

69

Figure 5-8. Mean stages of eruption, maxillary deciduous first molar.

Figure 5-9. Mean stages of mineralization, maxillary deciduous second molar.

70

Figure 5-10. Mean stages of eruption, maxillary deciduous second molar.

Figure 5-11. Mean stages of mineralization, mandibular deciduous first incisor.

71

Figure 5-12. Mean stages of mineralization, mandibular deciduous first incisor.

Figure 5-13. Mean stages of mineralization, mandibular deciduous second incisor.

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Figure 5-14. Mean stages of eruption, mandibular deciduous second incisor.

Figure 5-15. Mean stages of mineralization, mandibular deciduous canine.

73

Figure 5-16. Mean stages of eruption, mandibular deciduous canine.

Figure 5-17. Mean stages of mineralization, mandibular deciduous first molar.

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Figure 5-18. Mean stages of eruption, mandibular deciduous first molar.

Figure 5-19. Mean stages of mineralization, mandibular deciduous second molar.

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Figure 5-20. Mean stages of eruption, mandibular deciduous second molar.

Figure 5-21. Mean stages of mineralization, maxillary permanent first incisor.

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Figure 5-22. Mean stages of mineralization, maxillary permanent first incisor.

Figure 5-23. Mean stages of mineralization, maxillary permanent second incisor.

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Figure 5-24. Mean stages of eruption, maxillary permanent second incisor.

Figure 5-25. Mean stages of mineralization, maxillary permanent canine.

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Figure 5-26. Mean stages of eruption, maxillary permanent canine.

Figure 5-27. Mean stages of mineralization, maxillary permanent first premolar.

79

Figure 5-28. Mean stages of eruption, maxillary permanent first premolar.

Figure 5-29. Mean stages of mineralization, maxillary permanent second premolar.

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Figure 5-30. Mean stages of eruption, maxillary permanent second premolar.

Figure 5-31. Mean stages of mineralization, maxillary permanent first molar.

81

Figure 5-32. Mean stages of eruption, maxillary permanent first molar.

Figure 5-33. Mean stages of mineralization, maxillary permanent second molar.

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Figure 5-34. Mean stages of eruption, maxillary permanent second molar.

Figure 5-35. Mean stages of mineralization, maxillary permanent third molar.

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Figure 5-36. Mean stages of mineralization, maxillary permanent third molar.

Figure 5-37. Mean stages of mineralization, mandibular permanent first incisor.

84

Figure 5-38. Mean stages of eruption, mandibular permanent first incisor.

Figure 5-39. Mean stages of mineralization, mandibular permanent second incisor.

85

Figure 5-40. Mean stages of eruption, mandibular permanent second incisor.

Figure 5-41. Mean stages of mineralization, mandibular permanent canine.

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Figure 5-42. Mean stages of eruption, mandibular permanent canine.

Figure 5-43. Mean stages of mineralization, mandibular first premolar.

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Figure 5-44. Mean stages of eruption, mandibular first premolar.

Figure 5-45. Mean stages of mineralization, mandibular second premolar.

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Figure 5-46. Mean stages of eruption, mandibular second premolar.

Figure 5-47. Mean stages of mineralization, permanent mandibular first molar.

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Figure 5-48. Mean stages of eruption, permanent mandibular first molar.

Figure 5-49. Mean stages of mineralization, permanent mandibular second molar.

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Figure 5-50. Mean stages of eruption, permanent mandibular second molar.

Figure 5-51. Mean stages of mineralization, permanent mandibular third molar.

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Figure 5-52. Mean stages of eruption, permanent mandibular third molar.

Dentition summary

To evaluate the significance of the differences among the dentition, means

descriptive statistics of each tooth were calculated for males, females, and pooled

sexes using StatPlus and Microsoft Excel 2011. Two-sided t-tests were used to

compare the means between each tooth on both sides at each age, and evaluate which

differences were significant and what major trends were identifiable.

The first comparison evaluated significant differences between mineralization

and eruption development within the sexes by comparing means of mineralization and

eruptions stages at each age for left and right teeth of males, females, and pooled

sexes. (Because of the number of comparisons made, only significant results are

presented in the tables in this chapter.)

92

The comparison of male left and right dentition yielded only one significant result

for means of mineralization: the advancement of the right side over the left with regard

to the first maxillary premolar (Table 5-1). Comparing means of eruption yielded greater,

though still modest, significance clustered in the premolars and molars, most of them

indicating advancement of the left over the right (Table 5-2). None of the significant

results were evident in individuals of two consecutive years.

Table 5-1. Significant difference in mineralization means, male left vs. male right.

Left Right

Tooth Age N Mean Var. N Mean Var. Diff. t df

MX.PM3 12 41 10.39 11.04 45 11.80 4.44 -1.41 -2.32 84

Table 5-2. Significant difference in eruption means, male left vs. male right.

Left Right

Tooth Age N Mean Var. N Mean Var. Diff. t df

MX.PM3 13 24 3.13 1.77 24 3.75 0.37 -0.63 -2.10 46

MX.PM4 10 39 1.74 0.99 39 1.26 0.25 0.49 2.74 76

MX.M3 21 41 3.10 2.14 41 2.39 2.84 0.71 2.03 80

MX.M3 23 51 3.33 1.59 51 2.57 3.09 0.76 2.53 100

MD.M1 12 45 4.00 0.00 45 3.76 0.64 0.24 2.04 88

MD.M2 5 6 0.83 0.17 6 1.50 0.30 -0.67 -2.39 10

A greater, though still modest, number of significant results were evident in the

comparison mineralization means for female left vs. right dentition. In most, the left was

in advance of the right (Table 5-3). In eruption means, however, the right was in

advance of the left, for a modest number of teeth; no strong pattern was evident (Table

5-4). A review of the mineralization means of left and right sides for pooled sexes found

a nearly even divide between whether left or right was advanced (Table 5-5). The

eruption means of left and right sides for pooled sexes showed significant results

primarily in the posterior dentition, and with the left more often advanced (Table 5-6).

93

Table 5-3. Significant difference in mineralization means, female left vs. female right.

Left Right

Tooth Age N Mean Var. N Mean Var. Diff. t df

mx.dm1 7 16 17.31 0.23 16 16.94 0.20 0.38 2.30 30

mx.dm2 7 16 16.94 0.20 16 16.44 0.66 0.50 2.16 30

MX.I1 5 5 8.00 0.50 4 7.00 0.00 1.00 3.16

MD.C1 6 6 7.00 0.00 6 8.17 1.37 -1.17 -2.44 10

MD.C1 13 30 13.57 0.74 30 12.77 2.87 0.80 2.31 58

MD.M1 23 73 12.40 18.52 73 13.63 4.57 -1.23 -2.19 144

MD.M2 23 73 13.08 10.91 73 13.88 0.55 -0.79 -2.00 144

Table 5-4. Significant difference in eruption means, female left vs. female right.

Left Right

Tooth Age N Mean Var. N Mean Var. Diff. t df

MX.M2 9 26 1.04 0.04 25 1.48 1.01 -0.44 -2.16 49

MX.M3 8 23 0.04 0.04 23 0.26 0.20 -0.22 -2.11 44

MX.M3 19 40 2.75 2.04 39 2.05 2.47 0.70 2.07 77

MD.M1 8 23 4.00 0.00 23 3.30 1.58 0.70 2.65 44

MD.M2 8 23 1.17 0.15 23 1.83 1.51 -0.65 -2.42 44

MD.M2 23 73 3.68 1.14 73 4.00 0.00 -0.32 -2.53 144

Table 5-5. Significant difference in mineralization means, pooled left vs. pooled right.

Left Right

Tooth Age N Mean Var. N Mean Var. Diff. t df

mx.dm1 7 34 17.09 0.45 34 16.76 0.43 0.32 2.02 66

mx.dm2 7 34 16.71 0.40 34 16.26 0.69 0.44 2.47 66

md.dc1 6 16 15.56 0.66 16 15.06 0.20 0.50 2.16 30

md.dm1 9 46 17.07 0.68 46 16.46 2.65 0.61 2.26 90

MX.PM3 12 70 10.50 9.73 74 11.61 5.04 -1.11 -2.44 142

MX.PM3 13 52 11.79 11.62 54 12.91 3.56 -1.12 -2.08 104

MX.M1 23 124 13.79 2.70 124 13.06 11.47 0.73 2.17 246

MX.M2 9 44 6.68 1.29 45 7.33 1.82 -0.65 -2.47 87

MD.C1 6 16 6.69 0.90 16 7.94 4.46 -1.25 -2.16 30

MD.M1 13 54 13.00 11.77 54 13.94 0.05 -0.94 -2.02 106

MD.M1 23 124 12.11 21.14 124 13.15 10.28 -1.04 -2.07 246

94

Table 5-6. Significant difference in eruption means, pooled left vs. right.

Female Male

Tooth Age N Mean Var. N Mean Var. Diff. t df

mx.dm1 7 34 4.24 0.19 34 4.06 0.06 0.18 2.09 66

MX.PM4 10 72 1.74 0.99 72 1.33 0.54 0.40 2.77 142

MX.M1 8 49 3.96 0.04 49 3.65 0.77 0.31 2.38 96

MX.M2 9 46 1.07 0.11 45 1.42 0.79 -0.36 -2.53 89

MX.M3 14 30 1.33 1.68 30 0.73 0.62 0.60 2.17 58

MX.M3 19 63 2.81 1.96 62 2.10 2.32 0.71 2.72 123

MX.M3 21 93 3.11 1.99 93 2.67 2.64 0.44 1.98 184

MX.M3 23 124 3.11 1.99 124 2.69 2.80 0.42 2.13 246

MD.M1 5 11 2.82 0.96 11 1.82 1.36 1.00 2.17 20

MD.M1 8 49 4.00 0.00 49 3.59 1.00 0.41 2.86 96

MD.M1 12 74 4.00 0.00 74 3.85 0.40 0.15 2.02 146

MD.M2 5 11 0.91 0.09 11 1.91 1.29 -1.00 -2.82 20

MD.M2 8 49 1.14 0.13 49 1.55 1.00 -0.41 -2.69 96

MD.M3 6 16 0.00 0.00 16 0.25 0.20 -0.25 -2.24 30

Comparison of means of mineralization and eruption for males or females alone

with those for pooled sexes showed few significant differences among males (Table 5-7,

Table 5-8). No trend was evident for left or right sides in males (Table 5-9, Table 5-10).

Table 5-7. Significant difference in mineralization means, pooled left vs male left.

Pooled Male

Tooth Age N Mean Var. N Mean Var. Diff. t df

MX.I2 8 47 8.91 4.51 25 8.04 2.21 0.87 2.04 70

MX.C1 19 63 13.89 0.20 23 14.00 0.00 -0.11 -1.99 84

MD.C1 13 54 13.00 1.47 24 12.29 1.52 0.71 2.35 76

MD.PM4 19 63 12.95 12.53 23 13.96 0.04 -1.00 -2.24 84

Table 5-8. Significant difference in eruption means, pooled left vs male left.

Pooled Male

Tooth Age N Mean Var. N Mean Var. Diff. t df

MX.M2 13 54 3.07 1.39 24 2.46 1.65 0.62 2.00 76

MX.M3 13 53 0.96 0.73 23 0.65 0.24 0.31 2.00 74

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Table 5-9. Significant difference in mineralization means, pooled right vs male right.

Pooled Male

Tooth Age N Mean Var. N Mean Var. Diff. t df

MX.I2 8 48 9.58 7.99 25 8.00 3.50 1.58 2.86 71

MD.M2 13 54 11.63 4.73 24 10.29 4.65 1.34 2.52 76

Table 5-10. Significant difference in eruption means, pooled right vs male right.

Pooled Male

Tooth Age N Mean Var. N Mean Var. Diff. t df

md.dc1 11 82 4.52 0.25 49 4.33 0.22 0.20 2.26 129

md.dm2 8 49 4.08 0.08 26 4.00 0.00 0.08 2.07 73

MX.M3 13 54 0.89 0.67 24 0.58 0.25 0.31 2.02 76

Comparison between pooled left and female left means of mineralization and

eruption, however, showed a strong trend, in which the means for female posterior

deciduous dentition and permanent canine, in particular, were advanced over those for

the corresponding teeth of pooled sexes (Table 5-11, Table 5-12).

Table 5-11. Significant difference in mineralization means, pooled left vs female left.

Pooled Female

Tooth Age N Mean Var. N Mean Var. Diff. t df

mx.di1 10 72 17.93 0.07 33 18.00 0.00 -0.07 -2.30 103

mx.dc1 11 83 16.66 3.32 33 17.21 0.61 -0.55 -2.27 114

mx.dm1 13 54 17.89 0.10 30 18.00 0.00 -0.11 -2.57 82

md.dc1 11 82 17.33 0.79 33 17.76 0.25 -0.43 -3.26 113

md.dc1 13 54 17.93 0.07 30 18.00 0.00 -0.07 -2.06 82

MX.C1 11 82 10.72 3.44 33 11.52 3.32 -0.80 -2.11 113

MD.C1 12 73 11.30 3.44 29 12.21 2.17 -0.91 -2.59 100

MD.C1 13 54 13.00 1.47 30 13.57 0.74 -0.57 -2.49 82

MD.C1 15 22 13.55 0.55 11 13.91 0.09 -0.36 -2.00 31

MD.PM4 13 54 11.69 6.67 30 12.77 1.98 -1.08 -2.48 82

MD.M2 22 113 13.31 8.57 63 14.00 0.00 -0.69 -2.51 174

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Table 5-12. Significant difference in eruption means, pooled left vs female left.

Pooled Female

Tooth Age N Mean Var. N Mean Var. Diff. t df

mx.di1 10 72 4.93 0.07 33 5.00 0.00 -0.07 -2.30 103

mx.di2 10 72 4.85 0.13 33 4.97 0.03 -0.12 -2.34 103

mx.dm1 13 54 4.89 0.10 30 5.00 0.00 -0.11 -2.57 82

md.di2 11 82 4.95 0.05 33 5.00 0.00 -0.05 -2.04 113

md.dc1 11 82 4.57 0.25 33 4.79 0.17 -0.21 -2.36 113

md.dc1 13 54 4.93 0.07 30 5.00 0.00 -0.07 -2.06 82

MX.M2 13 54 3.07 1.39 30 3.57 0.67 -0.49 -2.25 82

MD.C1 11 83 2.52 1.81 33 3.15 1.51 -0.63 -2.44 114

MD.C1 13 54 3.80 0.47 30 4.00 0.00 -0.20 -2.19 82

MD.M2 22 112 3.79 0.82 62 4.00 0.00 -0.21 -2.51 172

The trend held on the right, though not as strongly (Table 5-13, Table 5-14). In contrast

to other findings, the female advancement was notable as a trend.

Table 5-13. Significant difference in mineralization means, pooled right vs female right.

Pooled Female

Tooth Age N Mean Var. N Mean Var. Diff. t df

MD.C1 11 83 11.06 3.74 33 11.88 3.36 -0.82 -2.14 114

MD.C1 12 74 11.68 4.63 29 12.66 2.16 -0.98 -2.64 101

md.dc1 10 72 16.44 4.14 33 17.09 0.77 -0.65 -2.27 103

md.dc1 12 74 17.58 0.58 29 17.83 0.22 -0.25 -1.99 101

md.dm1 11 82 17.06 3.59 33 17.61 0.25 -0.55 -2.41 113

MD.M2 13 54 11.63 4.73 30 12.70 2.29 -1.07 -2.64 82

mx.dc1 11 83 16.77 2.08 33 17.33 0.54 -0.56 -2.76 114

mx.dm2 8 49 15.90 3.84 23 16.61 0.52 -0.71 -2.24 70

MX.I2 8 48 9.58 7.99 23 11.30 7.31 -1.72 -2.47 69

Table 5-14. Significant difference in eruption means, pooled right vs female right.

Pooled Female

Tooth Age N Mean Var. N Mean Var. Diff. t df

md.dc1 11 82 4.52 0.25 33 4.82 0.15 -0.29 -3.34 113

MD.C1 11 83 2.55 1.86 33 3.24 1.31 -0.69 -2.76 114

MD.C1 14 30 3.67 0.78 13 4.00 0.00 -0.33 -2.07 41

MD.M1 12 74 3.85 0.40 29 4.00 0.00 -0.15 -2.02 101

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The trend was most pronounced when directly comparing the eruption and

mineralization means of males and females (Table 5-15 through Table 5-18). Significant

results were much more numerous than in other comparisons, and the trend was

overwhelmingly for advancement of the female mean over the male. The differences

were evident in both left and right, though more numerous on the left, and there were

many more significant differences for mineralization than for eruption. The effect is

noted in deciduous and permanent dentition, and is concentrated between eight and

thirteen years.

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Table 5-15. Significant difference in mineralization means, female left vs. male left.

Female Male

Tooth Age N Mean Var. N Mean Var. Diff. t df

mx.di1 6 6 17.67 0.27 10 17.00 0.44 0.67 2.24 14

mx.di1 7 16 17.31 0.36 18 17.72 0.21 -0.41 -2.21 32

mx.di1 10 33 18.00 0.00 39 17.87 0.11 0.13 2.36 70

mx.dc1 11 33 17.21 0.61 50 16.30 4.83 0.91 2.69 81

mx.dm1 13 30 18.00 0.00 24 17.75 0.20 0.25 2.77 52

mx.dm2 7 16 16.94 0.20 18 16.50 0.50 0.44 2.19 32

mx.dm2 9 26 17.04 0.04 20 16.70 0.43 0.34 2.23 44

md.di2 7 16 17.25 0.47 18 17.72 0.21 -0.47 -2.33 32

md.dc1 10 33 17.21 0.73 39 16.59 1.04 0.62 2.82 70

md.dc1 11 33 17.76 0.25 49 17.04 0.96 0.72 4.35 80

md.dc1 13 30 18.00 0.00 24 17.83 0.14 0.17 2.14 52

md.dm2 5 5 16.20 0.70 6 15.00 0.80 1.20 2.30 9

md.dm2 6 6 16.33 0.67 10 15.30 0.90 1.03 2.30 14

md.dm2 7 16 16.13 1.72 18 14.72 4.68 1.40 2.31 32

md.dm2 9 26 16.58 1.13 20 15.85 1.61 0.73 2.06 44

md.dm2 11 33 17.09 1.27 49 16.57 1.54 0.52 1.96 80

MX.I1 8 22 10.55 4.64 25 9.24 3.94 1.31 2.15 45

MX.I2 8 22 9.91 5.42 25 8.04 2.21 1.87 3.23 45

MX.C1 8 22 8.32 1.18 25 7.60 0.83 0.72 2.44 45

MX.C1 11 33 11.52 3.32 49 10.18 2.86 1.33 3.34 80

MX.C1 12 29 11.79 2.03 44 11.07 1.97 0.72 2.14 71

MX.C1 19 40 13.83 0.30 23 14.00 0.00 -0.18 -2.01 61

MX.PM4 4 2 7.00 0.00 2 2.00 2.00 5.00 5.00 2

MX.M1 4 2 14.00 0.00 2 7.00 2.00 7.00 7.00 2

MX.M2 12 29 10.52 7.12 44 9.05 5.63 1.47 2.41 71

MX.M2 13 30 12.23 6.39 24 10.79 6.26 1.44 2.09 52

MX.M3 13 30 6.10 14.99 23 3.74 5.84 2.36 2.72 51

MX.M3 19 40 10.90 19.43 23 12.87 8.57 -1.97 -2.13 61

MD.C1 12 29 12.21 2.17 44 10.70 3.42 1.50 3.85 71

MD.C1 13 30 13.57 0.74 24 12.29 1.52 1.28 4.30 52

MD.C1 15 11 13.91 0.09 11 13.18 0.76 0.73 2.61 20

MD.PM3 4 2 7.00 0.00 2 4.50 0.50 2.50 5.00 2

MD.PM3 10 33 9.15 3.70 39 8.21 3.48 0.95 2.11 70

MD.PM3 11 33 11.18 5.40 50 9.66 4.11 1.52 3.07 81

MD.PM3 12 29 11.66 2.95 45 10.40 6.70 1.26 2.51 72

MD.PM3 13 30 13.07 1.79 24 11.58 7.38 1.48 2.45 52

MD.PM4 13 30 12.77 1.98 24 10.33 9.45 2.43 3.59 52

MD.PM4 19 40 12.38 18.96 23 13.96 0.04 -1.58 -2.29 61

MD.M2 5 5 6.00 0.50 6 4.67 1.47 1.33 2.27 9

MD.M2 9 26 7.62 2.57 20 6.40 3.41 1.22 2.34 44

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Table 5-15. Continued

Female Male

Tooth Age N Mean Var. N Mean Var. Diff. t df

MD.M2 10 33 8.85 3.20 39 7.97 3.34 0.87 2.05 70

MD.M2 13 30 12.00 4.41 24 10.71 3.78 1.29 2.34 52

MD.M2 22 63 14.00 0.00 50 12.44 18.21 1.56 2.58 111

MD.M3 13 30 5.67 9.33 24 3.88 5.68 1.79 2.42 52

MD.M3 23 73 10.62 30.07 51 12.43 13.73 -1.81 -2.20 122

Table 5-16. Significant difference in eruption means, female left vs. male left.

Female Male

Tooth Age N Mean Var. N Mean Var. Diff. t df

mx.di1 7 16 4.38 0.25 18 4.72 0.21 -0.35 -2.10 32

mx.di1 10 33 5.00 0.00 39 4.87 0.11 0.13 2.36 70

mx.di2 10 33 4.97 0.03 39 4.74 0.20 0.23 2.93 70

mx.dm1 13 30 5.00 0.00 24 4.75 0.20 0.25 2.77 52

md.di2 7 16 4.38 0.25 18 4.72 0.21 -0.35 -2.10 32

md.di2 11 33 5.00 0.00 49 4.92 0.08 0.08 2.07 80

md.dc1 11 33 4.79 0.17 49 4.43 0.25 0.36 3.54 80

md.dc1 12 29 4.79 0.17 45 4.58 0.25 0.22 2.02 72

md.dc1 13 30 5.00 0.00 24 4.83 0.14 0.17 2.14 52

MX.I2 8 22 2.64 1.39 25 1.88 1.19 0.76 2.27 45

MX.C1 13 30 3.23 1.29 24 2.33 1.62 0.90 2.71 52

MX.PM3 8 23 1.09 0.08 26 1.42 0.41 -0.34 -2.41 47

MX.PM3 13 30 3.83 0.56 24 3.13 1.77 0.71 2.33 52

MX.M2 13 30 3.57 0.67 24 2.46 1.65 1.11 3.67 52

MX.M3 13 30 1.20 0.99 23 0.65 0.24 0.55 2.63 51

MD.C1 11 33 3.15 1.51 50 2.10 1.60 1.05 3.77 81

MD.C1 13 30 4.00 0.00 24 3.54 0.95 0.46 2.30 52

MD.PM3 11 33 3.00 1.31 50 2.34 1.54 0.66 2.49 81

MD.PM3 13 30 3.90 0.16 24 3.25 1.59 0.65 2.43 52

MD.PM4 7 16 1.44 0.80 18 0.94 0.06 0.49 2.15 32

MD.PM4 11 33 2.42 1.88 50 1.74 1.50 0.68 2.32 81

MD.M2 22 62 4.00 0.00 50 3.52 1.72 0.48 2.58 110

MD.M3 13 30 1.13 0.81 24 0.71 0.39 0.43 2.04 52

100

Table 5-17. Significant difference in mineralization means, female right vs. male right.

Female Male

Tooth Age N Mean Var. N Mean Var. Diff. t df

mx.di2 8 23 17.35 0.51 26 16.50 4.02 0.85 2.02 47

mx.dc1 11 33 17.33 0.54 50 16.40 2.78 0.93 3.48 81

mx.dm1 8 23 16.91 0.26 26 16.08 3.75 0.84 2.12 47

mx.dm1 11 33 17.58 0.25 50 17.20 1.27 0.38 2.07 81

mx.dm2 8 23 16.61 0.52 26 15.27 6.04 1.34 2.65 47

md.dc1 10 33 17.09 0.77 39 15.90 6.41 1.19 2.75 70

md.dc1 11 33 17.55 1.82 49 16.73 2.37 0.81 2.52 80

md.dc1 12 29 17.83 0.22 45 17.42 0.75 0.41 2.61 72

md.dm1 5 5 16.80 0.20 6 15.50 1.50 1.30 2.41 9

md.dm1 10 33 17.30 0.47 39 16.82 0.94 0.48 2.47 70

md.dm1 11 33 17.61 0.25 49 16.69 5.55 0.91 2.63 80

md.dm2 8 23 15.74 1.75 26 14.92 0.55 0.82 2.62 47

MX.I1 8 23 11.00 3.91 24 9.25 6.11 1.75 2.69 45

MX.I1 9 25 12.04 4.37 19 10.53 4.04 1.51 2.43 42

MX.I1 10 33 12.94 2.50 38 12.03 4.19 0.91 2.12 69

MX.I2 8 23 11.30 7.31 25 8.00 3.50 3.30 4.88 46

MX.I2 12 29 11.10 23.95 45 13.00 2.68 -1.90 -2.02 72

MX.C1 4 2 8.50 0.50 2 4.50 0.50 4.00 5.66 2

MX.C1 8 23 8.17 1.24 26 7.38 1.29 0.79 2.45 47

MX.C1 10 33 10.48 2.32 39 9.62 3.72 0.87 2.14 70

MX.C1 11 33 11.39 3.93 49 10.18 4.94 1.21 2.58 80

MX.C1 13 30 13.20 0.99 24 11.88 6.46 1.33 2.41 52

MX.PM4 4 2 7.50 0.50 2 3.50 0.50 4.00 5.66 2

MX.PM4 8 23 7.22 1.72 25 6.44 1.67 0.78 2.06 46

MX.PM4 13 30 12.93 3.44 24 11.71 4.65 1.23 2.21 52

MX.M1 4 2 14.00 0.00 2 5.00 2.00 9.00 9.00 2

MX.M2 10 33 8.48 3.57 39 7.62 2.77 0.87 2.05 70

MX.M2 13 30 12.60 4.39 24 11.04 4.82 1.56 2.64 52

MX.M3 13 30 5.47 11.91 24 3.42 5.82 2.05 2.56 52

MX.M3 18 18 9.11 25.16 15 12.20 5.17 -3.09 -2.34 31

MD.C1 10 33 10.82 4.34 39 9.46 3.57 1.36 2.87 70

MD.C1 11 33 11.88 3.36 50 10.52 3.32 1.36 3.31 81

MD.C1 12 29 12.66 2.16 45 11.04 5.27 1.61 3.68 72

MD.PM3 10 33 10.00 4.38 39 8.67 3.23 1.33 2.87 70

MD.PM4 13 30 12.07 8.27 24 10.42 9.38 1.65 2.02 52

MD.M1 4 2 14.00 0.00 2 5.50 4.50 8.50 5.67 2

MD.M2 10 33 8.70 1.66 39 7.85 4.03 0.85 2.17 70

MD.M2 13 30 12.70 2.29 24 10.29 4.65 2.41 4.64 52

MD.M3 13 30 5.40 7.01 24 3.75 4.72 1.65 2.52 52

101

Table 5-18. Significant difference in eruption means, female right vs. male right.

Female Male

Tooth Age N Mean Var. N Mean Var. Diff. t df

mx.di1 6 6 4.83 0.17 10 4.30 0.23 0.53 2.36 14

mx.di2 10 33 4.97 0.03 39 4.79 0.17 0.17 2.42 70

md.di2 7 16 4.38 0.25 18 4.72 0.21 -0.35 -2.10 32

md.dc1 11 33 4.82 0.15 49 4.33 0.22 0.49 5.12 80

md.dc1 12 29 4.86 0.12 45 4.62 0.24 0.24 2.45 72

md.dm2 8 23 4.17 0.15 26 4.00 0.00 0.17 2.15 47

MX.I1 8 23 3.39 1.07 25 2.68 1.64 0.71 2.12 46

MX.I2 8 23 2.83 1.42 25 2.08 1.16 0.75 2.27 46

MX.I2 10 33 3.85 0.20 39 3.49 0.84 0.36 2.19 70

MX.C1 13 30 3.43 1.01 24 2.50 2.00 0.93 2.73 52

MX.M3 13 30 1.13 0.88 24 0.58 0.25 0.55 2.76 52

MD.I2 7 16 2.44 1.46 18 3.33 1.18 -0.90 -2.26 32

MD.C1 11 33 3.24 1.31 50 2.10 1.72 1.14 4.19 81

MD.C1 14 13 4.00 0.00 17 3.41 1.26 0.59 2.16 28

MD.PM3 11 33 2.82 1.59 50 2.22 1.40 0.60 2.17 81

MD.PM4 13 30 3.20 1.54 24 2.46 1.91 0.74 2.05 52

MD.M1 12 29 4.00 0.00 45 3.76 0.64 0.24 2.04 72

While mineralization is regarded as more stable, lacking the susceptibility to

outside factors that may alter eruption timings, it should noted that mineralization, rather

than eruption, is significantly different in Kurdish males and females to a much greater

degree than is eruption. The literature generally regards females to be advanced over

males, and this is an accurate assessment of the Kurdish dentition, where females tend

to be advanced over males, and tend to have the left advanced over the right within

their own dentition. These factors stack. While this difference might suggest the utility of

separate male and female standards, the fact that many children are not aged with

knowledge of sex indicates that a pooled standard is appropriate. Comparison of

eruption and mineralization means of both males and females with the corresponding

pooled standards highlights this; the consequence of aging a male using a hypothetical

female standard, or vice versa, would be more likely to be incorrect than using a pooled

102

standard to age either a male or female. Finally, a review of the ages represented

indicates that the difference between male and female is not a persistent phenomenon

equally represented by all teeth in all stages of development at all ages. These trends

are not uniformly distributed and rarely persist to a significant degree over multiple

years for one tooth. To the degree that there is any pattern, the significant differences

appears to be most prevalent between eight and thirteen years, and would be most

likely to be a factor in estimating the age of individuals in that span.

The Kurdish Standard

Following the methodology of AlQahtani (2009) and AlQahtani et al. (2010), the

median, rather than mean, stage of the development for each tooth at each age was

used to generate an overall standard for Kurdish individuals. As the London Atlas and

Ubelaker atlas do not distinguish between sex, and skeletal remains of many juveniles

are analyzed with sex unknown, pooled data from both sexes representing the right

dentition was used to generate the new Kurdish standard (Table 5-19).

103

Table 5-19. The Kurdish Standard. Mineralization and Eruption are shown in alternating rows.

Age Mx/Md di1 di2 dc1 dm1 dm2 I1 I2 C1 PM3 PM4 M1 M2 M3

3 Mx Ac Ac Ac Ac Ac Coc Coc Coc Coc Coc Coc Coc Ab 3 Mx 4 4 4 4 4 1 1 1 1 1 1 1 Ab 3 Md Ac Ac Ac Ac Ac Coc Coc Coc Cco Ci Cr1/2 Cco Ab 3 Md 4 4 4 4 4 1 1 1 1 1 1 1 Ab 4 Mx Res3/4 Res1/2 Res1/2 Res1/2 Res1/2 Cr3/4 Cr3/4 Cr3/4 Cr1/2 Cr1/2 R1/2 Cco Ab 4 Mx 4 4 4 4 4 3 2 2 1 1 2 2 Ab 4 Md Res3/4 Res3/4 Ac Res1/4 Ac Ri Ri Crc Cr1/2 Cr1/2 R1/2 Cco Ab 4 Md 4 4 4 4 4 4 3 1 2 1 4 1 Ab 5 Mx Res3/4 Res3/4 Res1/2 Res3/4 Res3/4 Crc Crc Crc Cr3/4 Cr3/4 R1/4 Cr1/2 Ab 5 Mx 4 4 4 4 4 1 1 1 1 1 1 1 Ab 5 Md Res3/4 Res3/4 Res1/4 Res1/2 Res1/2 Ri Crc Crc Crc Cr1/2 R1/4 Cr1/2 Ab 5 Md 4 4 4 4 4 2 1 1 1 1 1 2 Ab 6 Mx Res3/4 Res3/4 Res1/4 Res3/4 Res3/4 Ri Crc Crc Cr3/4 Cr3/4 R3/4 Cr3/4 Ab 6 Mx 4 4 4 4 4 2 1 1 1 1 3 1 Ab 6 Md Ab Res3/4 Res1/4 Res1/2 Res1/4 R1/2 Ri Crc Crc Crc R3/4 Cr3/4 Ab 6 Md Ab 4 4 4 4 4 2 1 1 1 3 1 Ab 7 Mx Ab Res3/4 Res1/2 Res3/4 Res1/2 R1/4 Crc Ri Cr3/4 Cr3/4 A1/2 Cr3/4 Ab 7 Mx Ab 4 4 4 4 3 2 1 1 1 4 1 Ab 7 Md Ab Ab Res1/4 Res1/2 Res1/4 Rc R1/2 Crc Crc Crc A1/2 Cr3/4 Ab 7 Md Ab Ab 4 4 4 4 3 1 1 1 4 1 Ab

104

Table 5-19. Continued.

Age Mx/Md di1 di2 dc1 dm1 dm2 I1 I2 C1 PM3 PM4 M1 M2 M3

8 Mx Ab Res3/4 Res1/4 Res3/4 Res3/4 R1/2 R1/4 Ri Crc Crc Ac Cr3/4 Ab 8 Mx Ab 4 4 4 4 4 2 1 1 1 4 1 Ab 8 Md Ab Ab Res1/4 Res1/2 Res1/4 Rc Rc Crc Crc Crc A1/2 Crc Ab 8 Md Ab Ab 4 4 4 4 4 1 1 1 4 1 Ab 9 Mx Ab Ab Res1/2 Res3/4 Res3/4 Rc R3/4 R1/4 Ri Crc Ac Crc Ab 9 Mx Ab Ab 4 4 4 4 3 1 1 1 4 1 Ab 9 Md Ab Ab Res1/2 Res3/4 Res1/2 A1/2 Rc R1/4 Ri Crc A1/2 Crc Ab 9 Md Ab Ab 4 4 4 4 4 1 1 1 4 1 Ab 10 Mx Ab Ab Res1/2 Res3/4 Res3/4 A1/2 Rc R1/2 R1/4 Ri Ac Ri Ab 10 Mx Ab Ab 4 4 4 4 4 1 2 1 4 1 Ab 10 Md Ab Ab Res3/4 Res3/4 Res1/2 Ac Ac R1/2 R1/4 Ri Ac R1/4 Ci 10 Md Ab Ab 4 4 4 4 4 1 2 1 4 2 1 11 Mx Ab Ab Res3/4 Res3/4 Res3/4 Ac A1/2 R3/4 R1/2 R1/4 Ac Ri Ci 11 Mx Ab Ab 4 4 4 4 4 1 2 1 4 2 1 11 Md Ab Ab Ab Ab Res3/4 Ac Ac R3/4 R1/2 R1/4 Ac R1/4 Cco 11 Md Ab Ab Ab Ab 4 4 4 3 2 1 4 2 1 12 Mx Ab Ab Res3/4 Ab Res3/4 Ac Ac R3/4 Rc R3/4 Ac R1/4 Coc 12 Mx Ab Ab 4 Ab 4 4 4 2 3 2 4 2 1 12 Md Ab Ab Ab Ab Res3/4 Ac Ac Rc R3/4 R1/2 Ac R1/2 Coc 12 Md Ab Ab Ab Ab 4 4 4 4 4 2 4 2 1

105

Table 5-19. Continued.

Age Mx/Md di1 di2 dc1 dm1 dm2 I1 I2 C1 PM3 PM4 M1 M2 M3

13 Mx Ab Ab Ab Ab Ab Ac Ac A1/2 Ac A1/2 Ac A1/2 Coc 13 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 3 1 13 Md Ab Ab Ab Ab Ab Ac Ac A1/2 A1/2 Rc Ac A1/2 Cr1/2 13 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 1 14 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Coc 14 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 1 14 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Cr3/4 14 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 1 15 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Cr1/2 15 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 1 15 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Cr3/4 15 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 1 16 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ri 16 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 1 16 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ri 16 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 2 17 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac R1/4 17 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 1 17 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac R1/2 17 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 2

106

Table 5-19. Continued.

Age Mx/Md di1 di2 dc1 dm1 dm2 I1 I2 C1 PM3 PM4 M1 M2 M3

18 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac R1/2 18 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 2 18 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac R1/2 18 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 2 19 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac A1/2 19 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 2 19 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Rc 19 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4 20 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 20 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4 20 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 20 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4 21 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 21 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 3 21 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 21 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4 22 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 22 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4 22 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 22 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4

107

Table 5-19. Continued.

Age Mx/Md di1 di2 dc1 dm1 dm2 I1 I2 C1 PM3 PM4 M1 M2 M3

23 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 23 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4 23 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 23 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4 24 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 24 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4 24 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 24 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4 25 Mx Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 25 Mx Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4 25 Md Ab Ab Ab Ab Ab Ac Ac Ac Ac Ac Ac Ac Ac 25 Md Ab Ab Ab Ab Ab 4 4 4 4 4 4 4 4

108

Comparison

To facilitate comparison of the AlQahtani and Ubelaker atlases with the new

Kurdish standard, the modified Moorees and Bengston stages used in the AlQahtani et

al. (2010) description and the AlQahtani (2009) description of the findings used for that

atlas were used to render the AlQahtani and Ubelaker atlases as dental charts after the

above Table 5-19 for each stage. This greatly facilitated comparison; the new dental

charts, translated to their numeric equivalents and graphed, provided a convenient

means to intuitively compare the standards.

In the deciduous mandibular and maxillary dentition, the Kurdish standard is

slower to transition through the developmental stages, and slower to complete them

than is AlQahtani’s London Atlas, which standard is slower to complete than Ubelaker

(Figures 5-53, 5-54, 5-55, 5-56, 5-57, and 5-58). In the maxillary permanent dentition,

Kurdish mineralization development is earlier than reported by AlQahtani and consistent

with the timings of Ubelaker (Figure 5-59, 5-60, and 5-61). The permanent mandibular

dentition is consistent among the three, although the posterior dentition is delayed for

AlQahtani; the mineralization of the Kurdish standard is consistent with Ubelaker, noting

the development of the first molar in advance of the first permanent incisor, in contrary

to the findings of AlQahtani. AlQahtani reports the second premolar completing before

the second molar, which is contrary to the Kurdish standard and Ubelaker; however, the

timing of completion of the second premolar in the Kurdish standard is closer to that of

Ubelaker. Third molar completion is earlier than reported in AlQahtani but later than

reported in Ubelaker (Figures 5-62 through 5-64).

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Figure 5-53. Mineralization of maxillary deciduous dentition, Kurdish standard.

Figure 5-54. Mineralization of maxillary deciduous dentition, AlQahtani standard.

110

Figure 5-55. Mineralization of maxillary deciduous dentition, Ubelaker standard.

Figure 5-56. Mineralization of mandibular deciduous dentition, Kurdish standard.

111

Figure 5-57. Mineralization of maxillary deciduous dentition, AlQahtani standard.

Figure 5-58. Mineralization of mandibular deciduous dentition, Ubelaker standard.

112

Figure 5-59. Mineralization of maxillary permanent dentition, Kurdish standard.

Figure 5-60. Mineralization of maxillary permanent dentition, AlQahtani standard.

113

Figure 5-61. Mineralization of maxillary permanent dentition, Ubelaker standard.

Figure 5-62. Mineralization of mandibular permanent dentition, Kurdish standard.

114

Figure 5-63. Mineralization of mandibular permanent dentition, AlQahtani standard.

Figure 5-64. Mineralization of mandibular permanent dentition, Ubelaker standard.

115

Eruption timings in the Kurdish standard are later than Ubelaker and AlQahtani in

the maxillary deciduous dentition, with the exception of the first deciduous incisor

(Figures 5-65 through 5-67). Kurdish eruption timings are closer to AlQahtani than

Ubelaker in the deciduous mandibular, with earlier eruption for canines in the Kurdish

population; the timings of Ubelaker are more consolidated, with Ubelaker’s first incisor

erupting later and the molars erupting earlier than the AlQahtani or Kurdish populations

(Figures 5-68 through 5-70). Maxilary permanent eruption is most consolidated in

Ubelaker, intermediately so in AlQahtani, and least consolidated in the Kurdish

standard; in Ubelaker, the dentition is advanced relative to the Kurdish standard, while

AlQahtani exhibits a relative delay of posterior dentition (Figure 5-71 through 5-73). The

mandibular eruption timings of of Ubelaker and the Kurdish standard are comparable in

permanent dentition (Figures 5-74 through 5-75). The second permanent molar M2

completes later in AlQahtani than in Kurds in both maxillary and mandibular permanent

teeth.

Figure 5-65. Eruption of maxillary deciduous dentition, Kurdish standard.

116

Figure 5-66. Eruption of maxillary deciduous dentition, AlQahtani standard.

Figure 5-67. Eruption of maxillary deciduous dentition, Ubelaker standard.

117

Figure 5-68. Eruption of mandibular deciduous dentition, Kurdish standard.

Figure 5-69. Eruption of mandibular deciduous dentition, AlQahtani standard.

118

Figure 5-70. Eruption of mandibular deciduous dentition, Ubelaker standard.

Figure 5-71. Eruption of maxillary permanent dentition, Kurdish standard.

119

Figure 5-72. Eruption of maxillary permanent dentition, AlQahtani standard.

Figure 5-73. Eruption of maxillary permanent dentition, Ubelaker standard.

120

Figure 5-74. Eruption of mandibular permanent dentition, Kurdish standard.

Figure 5-75. Eruption of mandibular permanent dentition, AlQahtani standard.

121

Figure 5-76. Eruption of mandibular permanent dentition, Ubelaker standard.

Evaluation Against Control

For validation, the Kurdish standard was used to estimate the ages of the 195

individuals (99 male, 96 female) represented in the control database. The dentition of

each individual was scored to evaluate mineralization and eruption, and the individual

was assigned an estimated age based on comparison to the reference profile for each

age in the Kurdish standard. To calculate the accuracy of the assessment, the actual

age was subtracted from the estimated age. In the event that a range was given for the

estimated age (e.g., 8-9 years), the mean value of that range was used for calculation

purposes. Because the utility of the Kurdish standard ends at 20 years, full maturity was

given an age estimation of “20+,” and the difference from the actual age was calculated

in a manner appropriate to the situation. In the case of an individual of 25 years, for

example, an estimate of 20+ years would be read as an estimate of 25 years. If an

122

individual aged 16 years were estimated as 20+, the estimate would be read as 20

years, indicating a four-year overestimate.

Using the Kurdish atlas standard, 115 individuals (56 males, 53 females) of the

195 individuals were aged correctly to within one year. 53 individuals (37 male, 16

female) were aged exactly; 21 (7 males, 14 females) were underestimated by one year,

4 (1 male, 3 female) were underestimated by half a year, 6 (2 male, 4 female) were

overestimated by half a year, and 31 (11 male, 20 female) were overestimated by one

year. The mean difference between estimated age and actual age was 0.0128, with a

standard deviation of 2.458 years (Figure 5-77).

Figure 5-77. Actual age vs. estimated age, using Kurdish standard atlas.

The difference between the actual age and estimated age of the individual is

symmetrical about the mean until past the age of twenty, the end of the effectiveness of

the Kurdish standard. At that point, overestimation is effectively no longer a possibility,

so any error is in the direction of underestimation (Figure 5-78).

123

Figure 5-78. Actual age vs. difference between actual and estimated age, using Kurdish

standard atlas.

Comparison of Standards

The initial age assessment for the control group employed the Kurdish standard

as an atlas: for each individual, an overall assessment of age was issued based on the

overall resemblance to one or another stage in the Kurdish standard. Like all atlas

processes, this process was not automatable and was based entirely on human

judgment. Use of the scoring method allowed the examiner to automatically calculate

the score for each individual analyzed using Microsoft Excel functions, leading to a

much greater examination speed. Because it was not known how use of a scoring

method, rather than atlas method, would affect accuracy, the Kurdish method was also

translated to a scoring method to provide a basis for comparison.

In the scoring method, each tooth was given a development score equaling the

sum of the numeric equivalents of its mineralization and eruption stages. The sum of the

scores for all teeth represented the total score for the individual. The score proved

124

useful as an overall assessment of the dental arcade or the area of dentition in

question. The utility of the pooled right for development of the standard may be seen in

a comparison among median scores of left and right dentition of males, females, and

pooled sexes, where it presents as an intermediate value (Table 5-20, Figure 5-79).

Table 5-20. Mineralization and eruption stages, with corresponding numeric values. Age Female L Female R Male L Male R Pooled L Pooled R

3 242 249 242 249 4 368 374.5 292.5 290 321.5 327

5 337 334 313 311.5 320 318

6 351.5 349 333 335 340.5 339

7 352.5 351 361 362.5 359 357

8 371 376 359.5 360.5 364 367.5

9 385 389 374.5 377.5 380 386

10 410 411 395 400 406 407

11 445 440 421 416.5 431.5 427

12 450 453 442 450 447 450

13 493.5 492 468 467 484 484.5

14 496 494 496 496 496 495

15 496 494 492 491 495 495.5

16 500.5 499 502 502 501 501

17 506 505 510 506 508 504

18 511 512 511 508 512 507

19 514.5 513 518 515 516 513.5

20 518 518 518 518 518 518

21 518 518 518 517 518 517.5

22 518 518 518 518 518 518

23 518 518 518 518 518 518

24 518 518 518 518 518 518

25 518 518 518 518 518 518

125

Figure 5-79. Comparison of median scores for each age of left, right, male, female, and

pooled individuals of both sexes.

The Ubelaker, AlQahtani, and Kurdish standards in the experimental database

were scored by the same method in order to develop age estimation standards, then to

be evaluated against the control. The midpoint between the score for each age was

used as a sectioning point. Ubelaker and AlQahtani were translated to this scoring

regime without issue (Table 5-21 and Table 5-22). The paucity of individuals for the

younger age ranges for establishing the Kurdish standard meant that the scoring

method was useful only for differentiating the ages of Kurdish individuals aged over six

years (Table 5-23).

126

Table 5-21. Ubelaker standard, mineralization and eruption stages (sum method). Age Minimum Midpoint Max

3 253 268 4 268 283 294 5 294 305 318.5 6 318.5 332 348.5 7 348.5 365 376.5 8 376.5 388 400.5 9 400.5 413 432 10 432 451 463.5 11 463.5 476 484.5 12 484.5 493 497.5 13 14 15 497.5 502 510 16 17 18 19 20 21+ 510 518

Table 5-22. AlQahtani standard, mineralization and eruption stages (sum method). Age Minimum Midpoint Max

3 264 272 4 272 280 288 5 288 296 310.5 6 310.5 325 340 7 340 355 368.5 8 368.5 382 391.5 9 391.5 401 412 10 412 423 435.5 11 435.5 448 462 12 462 476 478 13 478 480 488.5 14 488.5 497 498.5 15 498.5 500 503 16 503 506 506 17 506 506 507 18 507 508 510 19 510 512 514 20 514 516 516 21 22 23+ 517 518

127

Table 5-23. Kurdish standard, mineralization and eruption stages (sum method). Age Minimum Midpoint Max

3 0 249 288 4 288 327 322.5 5 318 328.5 6 328.5 339 348 7 348 357 362.25 8 362.25 367.5 376.75 9 376.75 386 396.5 10 396.5 407 417 11 417 427 438.5 12 438.5 450 467.25 13 467.25 484.5 489.75 14 489.75 495 495.25 15 495.25 495.5 498.25 16 498.25 501 502.5 17 502.5 504 505.5 18 505.5 507 510.25 19 510.25 513.5 515.75 20+ 515.75 518

Plotting the midpoints of the scores for the AlQahtani, Ubelaker, and Kurdish

standards provides a clear illustration of the relationship among the standards. The

youngest points for the Kurdish score are, as noted, likely unreliable due to the paucity

of individuals of that age. The Kurdish standard is advanced over AlQahtani and

Ubelaker at the younger stages, then comes to lag behind them, with the greatest

discrepancy at ten and eleven years (Figure 5-80).

128

Figure 5-80. Midpoints of scores at prescribed age for AlQahtani, Ubelaker, and Kurdish

standards.

The scoring methods, in particular, tend to underestimate the ages of older

individuals, as can most readily be seen by comparing the difference with actual age

(Figure 5-81). A comparison of the Kurdish atlas estimate with the Kurdish scoring

estimate shows that this tendency is an artifact of the scoring method, and that the atlas

approach is more accurate than the scoring approach for estimating the age of older

individuals, even when the atlas and scoring approaches are making use of the same

standard for estimating age (Figure 5-82).

129

Figure 5-81. Actual age (X) vs. estimated age (Y) for all standards.

Figure 5-82. Actual age (X) vs. estimated age (Y) for Kurdish standard, contrasting atlas

and scoring methods.

The discrepancy between results for the Kurdish standard when using the atlas

and scoring method is readily explained by Demirjian’s own observation that the

inherent weakness of the scoring method is its dependence on the presence of each

130

tooth under consideration (Demirjian et al., 1973:216). This effect is inherent in the

automation of score calculation by spreadsheet formulas. A human surveying an atlas

can make a judgement when a tooth is absent, atypical, or obscured, based on the

development of the surrounding teeth, but automated scoring cannot; it records the

information only as lost points. A review of individuals aged over twenty years and

exhibiting a large difference (seven or more years) between the Kurdish atlas and

Kurdish scoring methods confirmed the individuals were missing permanent teeth.

Logically, this would result in similar bias in the AlQahtani and Ubelaker scoring

methods; and just such a bias is seen for underestimation of older individuals using

AlQahtani and Ubelaker standards when scoring methods are employed (Figure 5-83).

Figure 5-83. Actual age (X) vs. difference between estimated age and actual age (Y) for all standards.

. Separate consideration of the difference between estimated age and actual age

for the various standards provides a clear view of the tendencies of each standard. A

131

review of the difference between estimated age and actual age in using the AlQahtani

standard to assess the Kurdish control group shows that AlQahtani tends toward

underestimation beginning around ten years (Figure 5-84).

Figure 5-84. Actual age (X) vs. difference from estimated age (Y) for AlQahtani

standard.

The Ubelaker standard favors a stronger bias toward underestimation (Figure 5-85). By

contrast, the Kurdish scoring standard, while still presenting the tendency to

underestimate older individuals, is far more evenly divided between over and under-

(Figures 5-86 and 5-87).

132

Figure 5-85. Actual age (X) vs. difference from estimated age (Y) for Ubelaker standard.

Figure 5-86. Actual age (X) vs. difference from estimated age (Y) for Kurdish standard

(using automated scoring).

133

Figure 5-87. Actual age (X) vs. difference from estimated age (Y) for Kurdish standard

(atlas reference image scoring).

The Kurdish atlas assessed approximately equal numbers of males (58) and

females (57) within one year of actual age; all of the scoring methods, including the

Kurdish, estimated more females than males to within a year of actual age (Tables 5-24,

5-25, and 5-26).

134

Table 5-24. Kurdish standard aged within one year. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 1 0 1 6 6 2 4 2 3 2 2 7 12 3 9 1 8 3 7 8 15 7 8 5 4 5 4 9 19 7 12 5 6 6 8 10 18 7 11 1 6 2 7 11 11 7 4 5 4 6 3 12 15 10 5 3 1 7 3 13 8 4 4 1 3 2 3 14 5 2 3 1 1 2 2 15 7 2 5 2 4 1 5 16 7 2 5 0 3 0 2 17 5 2 3 0 1 0 2 18 5 2 3 0 1 0 2 19 8 5 3 5 3 5 1 20 9 6 3 3 2 4 2 21 8 5 3 3 1 2 0 22 7 5 2 5 1 4 2 23 10 7 3 5 2 2 2 24 9 7 2 4 0 1 1 25 9 7 2 7 2 2 1 TOTAL 195 99 96 58 57 56 60

135

Table 5-25. AlQahtani standard aged within one year. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 1 0 1 6 6 2 4 2 3 2 3 7 12 3 9 1 8 3 9 8 15 7 8 5 4 6 5 9 19 7 12 5 6 4 7 10 18 7 11 1 6 3 7 11 11 7 4 5 4 3 4 12 15 10 5 3 1 6 2 13 8 4 4 1 3 1 3 14 5 2 3 1 1 2 2 15 7 2 5 2 4 1 5 16 7 2 5 0 3 0 2 17 5 2 3 0 1 0 2 18 5 2 3 0 1 0 2 19 8 5 3 5 3 3 0 20 9 6 3 3 2 0 0 21 8 5 3 3 1 0 0 22 7 5 2 5 1 4 2 23 10 7 3 5 2 2 2 24 9 7 2 4 0 1 0 25 9 7 2 7 2 1 1 TOTAL 195 99 96 58 57 42 59

136

Table 5-26. Ubelaker standard aged within one year. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 1 0 1 6 6 2 4 2 3 2 3 7 12 3 9 1 8 2 8 8 15 7 8 5 4 7 5 9 19 7 12 5 6 4 8 10 18 7 11 1 6 4 7 11 11 7 4 5 4 2 4 12 15 10 5 3 1 4 3 13 8 4 4 1 3 0 2 14 5 2 3 1 1 0 0 15 7 2 5 2 4 0 3 16 7 2 5 0 3 0 2 17 5 2 3 0 1 0 0 18 5 2 3 0 1 0 0 19 8 5 3 5 3 0 0 20 9 6 3 3 2 4 2 21 8 5 3 3 1 2 0 22 7 5 2 5 1 4 2 23 10 7 3 5 2 3 3 24 9 7 2 4 0 2 2 25 9 7 2 7 2 2 1 TOTAL 195 99 96 58 57 42 56

The scoring methods tended to exactly estimate males and females at

approximately the same numbers; AlQahtani exactly estimated more females (60) than

males (56), Ubelaker exactly estimated more females (56) than males (42) and the

Kurdish atlas method exactly estimated substantially more males (37) than females (16)

(Tables 5-27, 5-28, and 5-29). No pattern was discernable in over or underestimation

(Tables 5-30 through 5-35).

137

Table 5-27. Kurdish standard aged exactly. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 1 0 1 6 6 2 4 0 1 2 2 7 12 3 9 0 1 0 4 8 15 7 8 2 0 2 1 9 19 7 12 2 1 0 2 10 18 7 11 0 1 1 2 11 11 7 4 1 0 1 0 12 15 10 5 0 0 4 0 13 8 4 4 1 1 1 2 14 5 2 3 0 1 0 0 15 7 2 5 2 1 0 2 16 7 2 5 0 1 0 1 17 5 2 3 0 0 0 0 18 5 2 3 0 0 0 1 19 8 5 3 2 0 1 0 20 9 6 3 3 2 4 2 21 8 5 3 3 0 2 0 22 7 5 2 5 1 4 2 23 10 7 3 5 2 2 2 24 9 7 2 4 0 1 1 25 9 7 2 7 2 2 1 TOTAL 195 99 96 37 16 27 26

138

Table 5-28. AlQahtani standard aged exactly. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 1 0 1 6 6 2 4 0 1 1 2 7 12 3 9 0 1 1 6 8 15 7 8 2 0 1 2 9 19 7 12 2 1 3 2 10 18 7 11 0 1 2 3 11 11 7 4 1 0 0 3 12 15 10 5 0 0 2 2 13 8 4 4 1 1 1 1 14 5 2 3 0 1 1 1 15 7 2 5 2 1 0 1 16 7 2 5 0 1 0 1 17 5 2 3 0 0 0 1 18 5 2 3 0 0 0 0 19 8 5 3 2 0 2 0 20 9 6 3 3 2 0 0 21 8 5 3 3 0 0 0 22 7 5 2 5 1 0 0 23 10 7 3 5 2 2 2 24 9 7 2 4 0 1 0 25 9 7 2 7 2 1 1 TOTAL 195 99 96 37 16 18 29

139

Table 5-29. Ubelaker standard aged exactly. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 1 0 1 6 6 2 4 0 1 1 2 7 12 3 9 0 1 0 4 8 15 7 8 2 0 0 2 9 19 7 12 2 1 4 3 10 18 7 11 0 1 1 4 11 11 7 4 1 0 1 1 12 15 10 5 0 0 1 1 13 8 4 4 1 1 0 0 14 5 2 3 0 1 0 0 15 7 2 5 2 1 0 3 16 7 2 5 0 1 0 0 17 5 2 3 0 0 0 0 18 5 2 3 0 0 0 0 19 8 5 3 2 0 0 0 20 9 6 3 3 2 0 0 21 8 5 3 3 0 2 0 22 7 5 2 5 1 4 2 23 10 7 3 5 2 3 3 24 9 7 2 4 0 2 2 25 9 7 2 7 2 2 1 TOTAL 195 99 96 37 16 21 29

140

Table 5-30. Kurdish standard overestimate. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 1 0 1 6 6 2 4 0 3 0 2 7 12 3 9 0 4 0 2 8 15 7 8 4 4 2 4 9 19 7 12 4 6 4 6 10 18 7 11 3 7 3 6 11 11 7 4 4 4 2 4 12 15 10 5 5 4 3 4 13 8 4 4 1 2 0 1 14 5 2 3 2 1 1 1 15 7 2 5 0 2 0 1 16 7 2 5 2 3 1 1 17 5 2 3 2 3 2 3 18 5 2 3 2 2 2 2 19 8 5 3 3 2 3 1 20 9 6 3 1 0 0 0 21 8 5 3 0 0 0 0 22 7 5 2 0 0 0 0 23 10 7 3 0 0 0 0 24 9 7 2 0 0 0 0 25 9 7 2 0 0 0 0 TOTAL 195 99 96 33 48 23 39

141

Table 5-31. AlQahtani standard overestimate. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 1 0 1 6 6 2 4 0 3 0 2 7 12 3 9 0 4 0 2 8 15 7 8 4 4 2 2 9 19 7 12 4 6 1 4 10 18 7 11 3 7 2 3 11 11 7 4 4 4 2 1 12 15 10 5 5 4 2 2 13 8 4 4 1 2 0 1 14 5 2 3 2 1 0 0 15 7 2 5 0 2 0 0 16 7 2 5 2 3 1 0 17 5 2 3 2 3 2 2 18 5 2 3 2 2 2 2 19 8 5 3 3 2 3 1 20 9 6 3 1 0 4 2 21 8 5 3 0 0 2 0 22 7 5 2 0 0 4 2 23 10 7 3 0 0 0 0 24 9 7 2 0 0 0 0 25 9 7 2 0 0 0 0 TOTAL 195 99 96 33 48 27 27

142

Table 5-32. Ubelaker standard overestimate. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 1 0 1 6 6 2 4 0 3 0 2 7 12 3 9 0 4 0 2 8 15 7 8 4 4 2 2 9 19 7 12 4 6 0 3 10 18 7 11 3 7 1 1 11 11 7 4 4 4 0 0 12 15 10 5 5 4 0 1 13 8 4 4 1 2 0 0 14 5 2 3 2 1 0 0 15 7 2 5 0 2 0 0 16 7 2 5 2 3 1 0 17 5 2 3 2 3 2 1 18 5 2 3 2 2 2 2 19 8 5 3 3 2 5 1 20 9 6 3 1 0 4 2 21 8 5 3 0 0 0 0 22 7 5 2 0 0 0 0 23 10 7 3 0 0 0 0 24 9 7 2 0 0 0 0 25 9 7 2 0 0 0 0 TOTAL 195 99 96 33 48 17 18

143

Table 5-33. Kurdish standard underestimate. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 0 0 0 6 6 2 4 2 0 0 0 7 12 3 9 3 4 3 3 8 15 7 8 1 4 3 3 9 19 7 12 1 5 3 4 10 18 7 11 4 3 3 3 11 11 7 4 2 0 4 0 12 15 10 5 5 1 3 1 13 8 4 4 2 1 3 1 14 5 2 3 0 1 1 2 15 7 2 5 0 2 2 2 16 7 2 5 0 1 1 3 17 5 2 3 0 0 0 0 18 5 2 3 0 1 0 0 19 8 5 3 0 1 1 2 20 9 6 3 2 1 2 1 21 8 5 3 2 3 3 3 22 7 5 2 0 1 1 0 23 10 7 3 2 1 5 1 24 9 7 2 3 2 6 1 25 9 7 2 0 0 5 1 TOTAL 195 99 96 29 32 49 31

144

Table 5-34. AlQahtani standard underestimate. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 0 0 0 6 6 2 4 2 0 1 0 7 12 3 9 3 4 2 1 8 15 7 8 1 4 4 4 9 19 7 12 1 5 3 6 10 18 7 11 4 3 3 5 11 11 7 4 2 0 5 0 12 15 10 5 5 1 6 1 13 8 4 4 2 1 3 2 14 5 2 3 0 1 1 2 15 7 2 5 0 2 2 4 16 7 2 5 0 1 1 4 17 5 2 3 0 0 0 0 18 5 2 3 0 1 0 1 19 8 5 3 0 1 0 2 20 9 6 3 2 1 2 1 21 8 5 3 2 3 3 3 22 7 5 2 0 1 1 0 23 10 7 3 2 1 5 1 24 9 7 2 3 2 6 2 25 9 7 2 0 0 6 1 TOTAL 195 99 96 29 32 54 40

145

Table 5-35. Ubelaker standard underestimate. AGE N MALE FEM ATLAS (M) ATLAS (F) SUM (M) SUM (F)

3 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 5 2 0 2 0 0 0 0 6 6 2 4 2 0 1 0 7 12 3 9 3 4 3 3 8 15 7 8 1 4 5 4 9 19 7 12 1 5 3 6 10 18 7 11 4 3 5 6 11 11 7 4 2 0 6 3 12 15 10 5 5 1 9 3 13 8 4 4 2 1 4 4 14 5 2 3 0 1 2 3 15 7 2 5 0 2 2 2 16 7 2 5 0 1 1 5 17 5 2 3 0 0 0 2 18 5 2 3 0 1 0 1 19 8 5 3 0 1 0 2 20 9 6 3 2 1 2 1 21 8 5 3 2 3 3 3 22 7 5 2 0 1 1 0 23 10 7 3 2 1 4 0 24 9 7 2 3 2 5 0 25 9 7 2 0 0 5 1 TOTAL 195 99 96 29 32 61 49

To assess the difference between the models, paired t-tests comparisons were

run comparing the mean of differences between actual and estimated age for each

standard (Table 5-36). All pooled and female sexes yielded significant differences in the

means for each model; the male standards exhibited less difference. The mean

difference for females was substantially lower than that for males and pooled sexes

using the Kurdish standard.

146

Table 5-36. Comparison of standards’ mean differences between actual age and estimated age.

N Mean Var N Mean Var Diff. t df

Kurdish vs AlQahtani (Male) 99 -1.84 13.69 99 -1.95 17.19 0.11 0.35 196

AlQahtani vs Ubelaker (Male) 99 -1.95 17.19 99 -2.47 17.37 0.53 1.50 196

Kurdish vs Ubelaker (Male) 99 -1.84 13.69 99 -2.47 17.37 0.64 2.02 196

Kurdish vs AlQahtani (Pooled) 195 -1.02 10.41 195 -1.26 12.19 0.25 2.12 388

Kurdish vs AlQahtani (Female) 96 -0.17 5.70 96 -0.55 6.17 0.39 3.12 190

AlQahtani vs Ubelaker (Female) 96 -0.55 6.17 96 -1.07 6.51 0.52 3.94 190

AlQahtani vs Ubelaker (Pooled) 195 -1.26 12.19 195 -1.78 12.46 0.52 4.14 388

Kurdish vs Ubelaker (Pooled) 195 -1.02 10.41 195 -1.78 12.46 0.77 6.56 388

Kurdish vs Ubelaker (Female) 96 -0.17 5.70 96 -1.07 6.51 0.91 7.13 190

Kurdish Atlas vs. Score 195 0.01 6.04 195 -1.02 10.41 1.03 12.19 388

Most notable was the comparison between the Kurdish Atlas method and the Kurdish

score: it was, by far, the result of greatest significance in comparing the methods. In all

but one instance during analysis, when there was a difference between atlas estimation

and estimation by scoring, the atlas estimation was more accurate than the score. While

the Kurdish standard is more accurate for aging a Kurdish population than AlQatani,

and considerably more so than Ubelaker, it would appear that human judgement in how

to adjust for missing teeth is a larger factor in age estimation than the difference

between the AlQahtani, Ubelaker, and present Kurdish standard.

147

CHAPTER 6 CONCLUSIONS

The Kurdish standard presented here is comparable to other standards currently

in use, including Ubelaker’s (Buikstra and Ubelaker 1994) and the London Atlas

(AlQahtani 2009; AlQahtani et al., 2010), and is more accurate than either for the

purpose of aging Kurdish individuals. The effectiveness of the Kurdish standard is

significantly reduced when used as part of automated scoring, rather than as an atlas,

which suggests that the human judgment combined with an accurate atlas is likely to

give superior results to basic mathematical formulae based on scoring criteria.

Among the Iraqi Kurdish population, females tend to be advanced over males; an

additional tendency for the left side to be advanced is particularly pronounced among

females. Significant differences between males and females are numerous; although

not necessarily persistent over the same teeth over multiple years, there is more

difference between males and females than among other groups.

Significant differences among left and right sides, and between the same sides of

pooled sexes and males or females, are relatively few and tend to not persist in the

same tooth over multiple years.

Although mineralization is viewed as being more stable than eruption and less

susceptible to outside influence, more significant differences are observed among

mineralization than eruption stages. This is likely due to the greater detail in which

mineralization is documented; a greater level of analysis is possible than for eruption

standards.

A pooled standard derived from and representing both males and females is an

appropriate and effective means of assessing the age of unknown individuals.

148

LIST OF REFERENCES

Abou El-Yazeed M, Abou Zeid W, Tawfik W. 2008. Dental maturation assessment by Nolla's technique on a group of Egyptian children. Australian Journal of Basic and Applied Sciences 2(4):1418-1424.

Acheson R. 1954. A method of assessing skeletal maturity from radiographs; a report from the Oxford child health survey. Journal of Anatomy 88:498-508.

Acheson R. 1957. The Oxford method of assessing skeletal maturity. Clinical Orthopaedics 10:19-39.

Agarwal N, Ahuja P, Sinha A, Singh A. 2012. Age estimation using maxillary central incisors: A radiographic study. Journal of Forensic Dental Sciences 4:97-100.

Ahmad S, Bister D, Cobourne MT. 2006. The clinical features and aetiological basis of primary eruption failure. European Journal of Orthodontics 28:535-540.

Ajmal M, Assiri K, Al-Ameer K, Assiri A, Luqman M. 2012. Age estimation using third molar teeth: a study on southern Saudi population. Journal of Forensic Dental Sciences 4:63-65.

Al-Jasser N. 2005. Cephalometric Evaluation for Saudi Population Using the Downs and Steiner Analysis. Journal of Contemporary Dental Practice 6(2):52-63.

Al-Jasser N, Bello L. 2003. Time of eruption of primary dentition in Saudi children. Journal of Contemporary Dental Practice 4(3):65-75.

Almonaitiene R, Balciuniene I, Titkuviene J. 2010. Factors influencing permanent teeth eruption. Part one -- general factors. Stomatologija 12(3):67-72.

AlQahtani SJ. 2009. Atlas of Tooth Development and Eruption. Queen Mary and Westfield College, Barts and the London School of Medicine and Dentistry. https://www.atlas.dentistry.qmul.ac.uk/.

AlQahtani SJ, Hector MP, Liversidge HM. 2010. Brief communication: The London atlas of human tooth development and eruption. American Journal of Physical Anthropology 142(3):481-490.

AlQahtani SJ, Hector MP, Liversidge HM. 2014. Accuracy of dental age estimation charts: Schour and Massler, Ubelaker, and the London Atlas. American Journal of Physical Anthropology 154:70-78.

Alshihri AM, Kruger E, Tennant M. 2015. Dental age assessment of Western Saudi children and adolescents. The Saudi Dental Journal 27:131-136.

Altalie S TP, Fieuws S, Willems G. 2014. Optimal dental age estimation practice in United Arab Emirates’ children. Journal of Forensic Sciences 59:383-385.

149

Altunsoy M NB, Akkemik O, Ok E, Evcil MS. 2015. Applicability of the Demirjian method for dental age estimation in western Turkish children. Acta Odontologica Scandinavica 73:121-125.

Alvesalo L. 1997. Sex chromosomes and human growth: a dental approach. Human Genetics 101:1-5.

Amariti ML, Restori M, De Ferrari F, Paganelli C, Faglia R, Legnani G. 1999. Age determination by teeth examination: a comparison between different morphologic and quantitative analyses. Journal of Clinical Forensic Medicine 6:85-89.

Amoedo O. 1898. L’Art Dentaire en Medicine Legale. Paris: Masson et Cie.

Anderson DL, Thompson GW, Popovich F. 1976. Age of attainment of mineralization stages of the permanent dentition. Journal of Forensic Sciences 21:191-200.

Anderson JY, Trinkaus E. 1998. Patterns of sexual, bilateral and interpopulational variation in human femoral neck-shaft angles. Journal of Anatomy 192:279-285.

Anemone RL, Mooney MP, Siegel MI. 1996. Longitudinal study of dental development in chimpanzees of known chronological age: Implications for understanding the age at death of Plio-Pleistocene hominids. American Journal of Physical Anthropology 99:119-133.

Ayoub F, Rizk A, Yehya M, Cassia A, Chartouni S, Atiyeh F, Majzoub Z. 2009. Sexual dimorphism of mandibular angle in a Lebanese sample. Journal of Forensic and Legal Medicine 16(3):121-124.

Baghdadi ZD. 2013. Dental Maturity in Saudi Children Using the Demirjian Method: A Comparative Study and New Prediction Models. ISRN Dentistry 2013(390314):1-9.

Baghdadi ZD. 2013. Dental maturity of Saudi children: Role of ethnicity in age determination. Imaging Science in Dentistry 43:267-272.

Baghdadi ZD. 2014. Testing international dental maturation scoring system and population-specific Demirjian versions on Saudi sub-population. Journal of Clinical and Experimental Dentistry 6:e138-144.

Baghdady VS, Ghose LJ. 1981. Eruption time of primary teeth in Iraqi children. Community Dentistry and Oral Epidemiology 9:245-246.

Bagherian A, Sadeghi M. 2011. Assessment of dental maturity of children aged 3.5 to 13.5 years using the Demirjian method in an Iranian population. Journal of Oral Science 53(1):37-42.

150

Bagherpour A, Anbiaee N, Partovi P, Golestani S, Afzalinasab S. 2012. Dental age assessment of young Iranian adults using third molars: A multivariate regression study. Journal of Forensic and Legal Medicine 19:407-412.

Bagherpour A, Imanimoghaddam M, Bagherpour M, Einolghozati M. 2010. Dental age assessment among Iranian children aged 6-13 years using the Demirjian method. . Forensic Science International 197(1-3):121.e121-121.e124.

Bang G, Ramm E. 1970. Determination of age in humans from root dentin transparency. Acta Odontolica Scandinavica 28:3-35.

Bengston R. 1935. A study of the time of eruption and root development of the permanent teeth between six and thirteen years. Northwestern University Bulletin 35:3-9.

Bergamo AL, de Queiroz CL, Sakamoto HE, da Silva RHA. 2016. Dental Age Estimation Methods in Forensic Dentistry: Literature Review. Peertechz Journal of Forensic Science and Technology 1:17-22.

Bhanat S, Patel D. 2013. Dental & Skeletal maturity indicators of Chronological age: Radiographic evaluation amongst children in Gujarat, India. IOSR Journal of Dental and Medical Sciences 6(4):6-12.

Black GV. 1883. Lines of contemporaneous calcification of the teeth. Annual Journal of the Illinois State Dental Society 1883:1.

Black SM, Aggrawal A, Payne-James J. 2010. Age Estimation in the Living: The Practitioner's Guide. Hoboken: John Wiley and Sons.

Blankenstein R, Cleaton-Jones PE, Luk KM, Fatti LP. 1990. The onset of eruption of the permanent dentition amongst South African black children. Archives of Oral Biology 35(3):225-228.

Bosmans N, Ann P, Alya M, Willems G. 2005. The application of Kvaal’s dental age calculation technique on panoramic dental radiographs. Forensic Science International 153:208-212.

Boutourline E, Tesi G. 1972. Deciduous tooth eruption in a region of Southern Tunisia. Human Biology 44:433-442.

Brady W. 1924. A Chart of the Average Time of Development, Eruption, and Absorption of the Teeth. Kansas City: Willam J. Brady.

Braga J, Heuze Y, Chabadel O, Sonan N, Gueramy A. 2005. Non-adult dental age assessment: Correspondence analysis and linear regression versus Bayesian predictions. International Journal of Legal Medicine 119:260-274.

151

Brkic H, Milicevic M, Petroveki M. 2006. Age estimation methods using anthropological parameters on human teeth–(A0736). Forensic Science International 162:13-16.

Brook AH, Barker DK. 1972. Eruption of teeth among the racial groups of eastern New Guinea: a correlation of tooth eruption with calendar age. Archives of Oral Biology 17(4):751-759.

Brumit PC, Stimson PG. 2010. History of Forensic Dentistry. In: Senn DR, Stimson PG, editors. Forensic Dentistry. Second ed. Boca Raton: CRC Press. p.11-24.

Buikstra JE, Ubelaker DH. 1994. Standards for data collection from human skeletal remains. Fayetteville: Arkansas Archaeological Survey.

Buxton LHD, Rice DT. 1931. Report on the Human Remains Found at Kish. Journal of the Royal Anthropological Institute 61:57-119.

Caldas I, Carneiro JLs, Teixeira A, Matos E, Afonso Ar, Magalhaes T. 2012. Chronological course of third molar eruption in a Portuguese population. International Journal of Legal Medicine 126:107-112.

Cameriere R, De Luca S, Alemán I, Ferrante L, Cingolani M. 2012. Age estimation by pulp/tooth ratio in lower premolars by orthopantomography. Forensic Science International 214:105-112.

Cameriere R, Ferrante L, Cingolani M. 2004. Variations in pulp/tooth area ratio as an indicator of age: a preliminary study. Journal of Forensic Sciences 49(2):1-3.

Cameriere R, Ferrante L, Cingolani M. 2004. Precision and reliability of pulp/tooth area ratio (RA) of second molar as indicator of adult age. Journal of Forensic Sciences 49:1-6.

Cameriere R, Ferrante L, Cingolani M. 2006. Age estimation in children by measurement of open apices in teeth. International Journal of Legal Medicine 120:49-52.

Cameriere R, Ferrante L, Mirtella D, Cingolani M. 2006. Carpals and epiphyses of radius and ulna as age indicators. International Journal of Legal Medicine 120:143-146.

Cantekin K, Yilmaz Y, Demirci T, Celikoglu M. 2012. Morphologic analysis of third-molar mineralization for eastern Turkish children and youth. Journal of Forensic Sciences 57:531-534.

Cardoso HFV. 2007a. Accuracy of developing tooth length as an estimate of age in human skeletal remains: the deciduous dentition. Forensic Science International 172(1):17-22.

152

Cardoso HFV. 2007b. Environmental effects on skeletal versus dental development: using a documented subadult skeletal sample to test a basic assumption in human osteological research. American Journal of Physical Anthropology 132:223-233.

Caro A, Contreras. 2001. Analysis and comparison de cuatro methods radiographics para determiner la ede dental en dientes permanent. International Journal of Dental Anthropology 2:9-15.

Carr LM. 1962. Eruption ages of permanent teeth. Australian Dental Journal 7:367-373.

Celik S, Celikel A, Yengil E, Altan A. 2014. Applicability of the Demirjian method for dental assessment of southern Turkish children. Journal of Forensic and Legal Medicine 25:1-5.

Chaillet N, Nyström M, Demirjian A. 2005. Comparison of Dental Maturity in Children of Different Ethnic Origins: International Maturity Curves for Clinicians. Journal of Forensic Sciences 50(5):1-11.

Chantre E. 1895. Recherches anthropologiques en Transcaucasie, Asie-Mineure et Syrie. Lyon.

Chudasama PN, Roberts GJ, Lucas VS. 2012. "Dental age assessment (DAA): a study of a Caucasian population at the 13 year threshold". Journal of Forensic and Legal Medicine 19(1):22-28.

Condon K, Rose JC. 1992. Intertooth and intratooth variability in the occurrence of developmental defects. In: Goodman AH, Capasso LL, editors. Recent Contribution to the Study of Enamel Developmental Defects. Journal of Paleopathology, Monographic publications, No 2. Chieti, Italy: Edigrafital Teramo. p 61-77.

Coppa A, Cucina A, Chiarelli B, Calderon FL, Mancinelli D. 1995. Dental anthropology and paleodemography of the pre-Columbian populations of Hispaniola from the third millennium B.C. to the Spanish conquest. Human Evolution 10:153-167.

Cruz-Landeira A, Linares-Argote J, Martinez-Rodriguez Ma, Rodriguez-Calvo MaS, Otero XL, Concheiro L. 2009. Dental age estimation in Spanish and Venezuelan children. Comparison of Demirjian and Chaillet’s scores. International Journal of Legal Medicine 124:105-112.

Dahlberg AA. 1960. The dentition of the first agriculturists (Jarmo, Iraq). American Journal of Physical Anthropology 18(4):243-256.

Dahlberg AA, Menegaz-Bock RM. 1958. Emergence of the permanent teeth in Pima Indian children. Journal of Dental Research 37:1123-1140.

153

Daito M, Tanaka M, and Hieda T. 1992. Clinical observations on the development of third molars. Journal of Osaka Dental University 26:91-104.

Dalitz GD. 1962. Age determination of adult human remains by teeth examination. Journal of the Forensic Science Society 3(1):11-21.

De Angelis D, Gibelli D, Merelli V, Botto M, Ventura F, Cattaneo C. 2014. Application of age estimation methods based on teeth eruption: How easy is Olze method to use? International Journal of Legal Medicine 128:841-844.

De Melo M, Freitas E, Salzano F. 1975. Eruption of permanent teeth in Brazilian Whites and Blacks. American Journal of Physical Anthropology 42(1):145-150.

Dean MC, Wood B. 1981. Developing pongid dentition and its use for ageing individual crania in comparative cross-sectional growth studies. Folia Primatologica 36:111-127.

Demirjian A. 1986. Dentition. In: Falkner F, Tanner JM, editors. Human Growth—A Comprehensive Treatise. New York: Plenum Press. p 198-269.

Demirjian A, Goldstein H. 1976. New systems for dental maturity based on seven and four teeth. Annals of Human Biology 3:411-421.

Demirjian A, Goldstein H, Tanner JM. 1973. A new system of dental age assessment. Human Biology 45(2):211-227.

Demisch A, Wartmann P. 1956. Calcification of the mandibular third molar and its relation to skeletal and chronological age in children. Child Development 27:459-473.

Diamanti J, Townsend GC. 2003. New standards for permanent tooth emergence in Australian children. Australian Dental Journal 48(1):39-42.

Dio C. 1925. Roman History. Loeb Classical Library. Cambridge, MA: Harvard University Press.

Edgar HJH. 2005. Prediction of Race Using Characteristics of Dental Morphology. Journal of Forensic Sciences 50(2):1-5.

Ehrich R. 1939. Late cemetery crania. In: Starr R, editor. Nuzi. Cambridge, MA: Harvard University Press. p 570-589.

Fanning EA. 1961. A longitudinal study of tooth formation and root resorption. New Zealand Dental Journal 57:202-217.

Fanning EA, Brown T. 1971. Primary and permanent tooth development. Australian Dental Journal 16:41-43.

154

Fanning EA, Moorrees CF. 1969. A comparison of permanent mandibular moral formation in Australian Aborigines and Caucasoids. Archives of Oral Biology 14:999-1006.

Fenn J, Hines D, Hanson I. 2014. Building standards and capacity to investigate mass graves in Iraq: Requirements and challenges. American Academy of Forensic Sciences 2014 Annual Meeting. Seattle, WA.

Field H. 1936. The Arabs of Iraq. American Journal of Physical Anthropology 21(1):49-56.

Folayan M, Owotade F, Adejuyigbe E, Sen S, Lawal B, Ndukwe K. 2007. The timing of eruption of the primary dentition in Nigerian children. American Journal of Physical Anthropology 134(4):443-448.

Folayan M, Owotade F, Adejuyigbe E, Sen S, Lawal B, Ndukwe K. 2007. The Timing of Eruption of the Primary Dentition in Nigerian Children. American Journal of Physical Anthropology 134:443-448.

Foti B, Lalys L, Adalian P, Giustiniani J, Maczel M, Sugnoli M, Dutour O, Leonetti G. 2003. New forensic approach to age determination in children based on tooth eruption. Forensic Science International 132:49-56.

Franco A, Thevissen P, Fieuws S, Henrique P, Souza C, Willems G. 2013. Applicability of Willems model for dental age estimations in Brazilian children. Forensic Science International 231:401.e1-401.e4.

Friedlaender J, Bailit H. 1969. Eruption times of the deciduous and permanent teeth of natives on Bougainville Island, territory of New Guinea: A study of racial variation. Human Biology 41:51-65.

Friedrich R, Habib S, Scheuer H. 2009. [Eruption times of permanent teeth in children and adolescents in Latakia (Syria)]. [Article in German]. Archiv für Kriminologie 223(3-4):84-97.

Friedrich R, Kamalwand N, Jürgen S, Scheuer H. 2007. [Eruption times of permanent teeth in male children and adolescents of Tehran (Iran)]. [Article in German]. Archiv für Kriminologie 219(5-6):145-168.

Friedrich R, Katerji H, Wedl JS, Scheuer H. 2006. [Eruption times of permanent teeth in children and adolescents of Paderborn, Westphalia, Germany]. [Article in German]. Archiv für Kriminologie 217(1-2):20-35.

Friedrich R, Leist A, Scheuer H. 2008. [Eruption times of permanent teeth in children and adolescents in the German state of Saarland]. [Article in German]. Archiv für Kriminologie 222(3-4):73-104.

155

Galic I, Vodanovic M, Cameriere R, Nakas E, Galic E, Selimovic E, Brkic H. 2011. Accuracy of Cameriere, Haavikko, and Willems radiographic methods on age estimation on Bosnian–Herzegovian children age groups 6–13. International Journal of Legal Medicine 125:315-321.

Garn SM. 1952. Physical growth and development. American Journal of Physical Anthropology 10:169-192.

Garn SM. 1971. Human Races. Springfield, IL: Thomas.

Garn SM, Moorrees CFA. 1951. Stature, body build and tooth emergence in the Aleutian Aleut children. Child Development 22:262-270.

Garn SM, Sandusky ST, Nagy JM, McCann MB. 1972. Advanced skeletal development in low-income Negro children. Journal of Pediatrics 80:965-969.

Garn SM, Sandusky ST, Nagy JM, Trowbridge FL. 1973. Negro-Caucasoid differences in permanent tooth emergence at a constant income level. Archives of Oral Biology 18(5):609-615.

Geller F, Feenstra B, Zhang H, Shaffer JR, Hansen T, Esserlind A-L, Boyd HA, Nohr EA, Timpson NJ, Fatemifar G. 2011. Genome-Wide Association Study Identifies Four Loci Associated with Eruption of Permanent Teeth. PLOS Genetics 7(9): e1002275. doi:10.1371/journal.pgen.1002275

Ghose LJ, Baghdady VS. 1979. Analysis of the Iraqi Dentition: Mesiodistal Crown Diameters of Permanent Teeth. Journal of Dental Research 58(3):1047-1054.

Ghose LJ, Baghdady VS. 1981. Eruption time of permanent teeth in Iraqi school children. Archives of Oral Biology 26:13-15.

Gillett RM. 1997. Dental emergence among urban Zambian school children: An assessment of the accuracy of three methods in assigning ages. American Journal of Physical Anthropology 102:447-454.

Gleiser I, Hunt EE. 1955. The permanent mandibular first molar; its calcification, eruption and decay. American Journal of Physical Anthropology 13:253–284.

Goldberg M, Septier D, Lecolle S, Chardin H, Quintana MA, Acevedo AC, Gafni G, Dillouya D, Vermelin L, Thonemann B, Schmalz G, Bissila-Mapahou P, Carreau JP. 1995. Dental mineralization. International Journal of Developmental Biology 39:93-110.

Gorgani N, Sullivan RE, DuBois L. 1990. A radiographic investigation of third-molar development. Journal of Dentistry for Children 57:106-110.

Gravely JF. 1965. A radiographic survey of third molar development. British Dental Journal 119:397-401.

156

Greulich WW, Pyle SI. 1959. Radiographic Atlas of Skeletal Development of the Hand and Wrist. Stanford, CA: Stanford University Press.

Gron A. 1962. Prediction of tooth emergence. Journal of Dental Research 1962 41:573-585.

Guo Y-c, Yan C-x, Lin X-w, Zhou H, Li J-p, Pan F, Zhang Z-y, Wei L, Tang Z, Chen T. 2015. Age estimation in northern Chinese children by measurement of open apices in tooth roots. International Journal of Legal Medicine 129:179-186.

Gupta A, Hiremath S, Singh S, Poudyal S, Niraula S, Baral D, Singh R. 2007. Emergence of primary teeth in children of Sunsari district of eastern Nepal. McGill Journal of Medicine 10(1):11-15.

Gupta R, Rajvanshi H, Effendi H, Afridi S, Vuyyuru KK, Vijay B, Dhillon M. 2014. Dental age estimation by Demirjian’s and Nolla’s method in adolescents of western Uttar Pradesh. Journal of Head and Neck Physicians and Surgeons 3(1):50-56.

Gupta R, Sivapathasundharam B, Einstein A. 2007. Eruption age of permanent mandibular first molars and central incisors in the south Indian population. Indian Journal of Dental Research 18(4):186-189.

Gustafson G. 1950. Age determinations of teeth. Journal of the American Dental Association 41:45-54.

Gustafson G, Koch G. 1974. Age estimation up to 16 years of age based on dental development. Odontologisk Revy 25:297-306.

Haataja J. 1965. Development of the mandibular permanent teeth of Helsinki children. Proceedings of the Finnish Dental Society 61:43-53.

Haavikko K. 1970. The formation and alveolar and clinical eruption of permanent teeth. An orthopantomographic study. Proceedings of the Finnish Dental Society 66:103-170.

Haavikko K. 1974. Tooth formation age estimated on a few selected teeth: a simple method for clinical use. Proceedings of the Finnish Dental Society 70:15-19.

Hagg U, Matsson L. 1985. Dental maturity as an indicator of chronological age: the accuracy and precision of three methods. European Journal of Orthodontics 7:25-34.

Halikis S. 1961. The variability of eruption of permanent teeth and loss of deciduous teeth in Western Australian children. I. Times of eruption of the permanent teeth. Aust Dent J 6:137-140.

Harris EF, McKee JH. 1990. Tooth mineralization standards for blacks and whites from the Middle Southern United States. Journal of Forensic Sciences 35(4):859-872.

157

Harris MJP, Nortje CJ. 1984. The mesial root of the third mandibular molar. A possible indicator of age. Journal of Forensic Odonto-Stomatology 2:39-43.

Hassanali J, Odhiambo JW. 1981. Ages of eruption of the permanent teeth in Kenyan African and Asian children. Annals of Human Biology 8:425-434.

Hazza'a A, G. A-J. 2006. Dental development in subjects with thalassemia major. Journal of Contemporary Dental Practice 7(4):63-70.

Hegde R, Sood P. 2002. Dental maturity as an indicator of chronological age: radiographic evaluation of dental age in 6 to 13 years children of Belgaum using Demirjian methods. Journal of the Indian Society of Pedodontics and Preventive Dentistry 20:132-138

Heiple KG, Lovejoy CO. 1971. The distal femoral anatomy of Australopithecus. American Journal of Physical Anthropology 35(1):75-84.

Helm S. 1969. Secular trend in tooth eruption: A comparative study of Danish school children of 1913 and 1965. Archives of Oral Biology 14(10):1177-1191.

Heuzè Y. 2004. Chronologie et etiologie de la maturation macro-structurale des dents definitives. Doctoral thesis. Université Bordeaux I, Talence.

Heuzé Y, Braga J. 2008. Application of non-adult Bayesian dental age assessment methods to skeletal remains: the Spitalfields collection. Journal of Archaeological Science 35(2):368-375.

Heuzé Y, Cardoso HFV. 2008. Testing the quality of nonadult Bayesian dental age assessment methods to juvenile skeletal remains: The Lisbon collection children and secular trend effects. American Journal of Physical Anthropology 135(3):275-283.

Hiernaux J. 1968. Ethnic differences in growth and development. Eugenics Quarterly 15(12-21).

Hillson S. 2005. Teeth. Cambridge: Cambridge University Press.

Holman DJ, Jones RE. 1998. Longitudinal analysis of deciduous tooth emergence: ii. parametric survival analysis in Bangladeshi, Guatemalan, Japanese, and Javanese children. American Journal of Physical Anthropology 105:209-230.

Holman DJ, Jones RE. 2003. Longitudinal analysis of deciduous tooth emergence: III. Sexual dimorphism in Bangladeshi, Guatemalan, Japanese, and Javanese children. American Journal of Physical Anthropology 122(3):269-278.

Holman DJ, Yamaguchi K. 2005. Longitudinal analysis of deciduous tooth emergence: IV. Covariate effects in Japanese children. American Journal of Physical Anthropology 126(3):352-358.

158

Houpt MJ, Adu-Aryee S, Grainger RM. 1967. Eruption times of permanent teeth in the Brong Ahafo region of Ghana. American Journal of Orthodontics 53:95-99.

Huel R, Amory S, Bilić A, Vidović S, Jasaragić E, Parsons TJ. 2012. DNA extraction from aged skeletal samples for STR typing by capillary electrophoresis. Methods in Molecular Biology 830:185-198.

Human Rights Watch. 2004. Iraq: State of the Evidence. Human Rights Watch,16(7E). https://www.hrw.org/sites/default/files/reports/iraq1104.pdf

Hunt Jr. EE, Gleiser I. 1955. The estimation of age and sex of preadolescent children from bones and teeth. American Journal of Physical Anthropology 13(3):479-487.

Hurme VO. 1946. Decay of the deciduous teeth of Formosa Chinese. An analytical summary and interpretation of certain statistics published by Maruyama. Journal of Dental Research 25:127-136.

Igbigbi PS, Msamati BC, Matanje B. 2003. Normal axial angles of the knee joint in adult indigenous Malawians. East African Medical Journal 80(8):415-418.

Irurita J, Alema I, López-Lázaro S, Viciano J, Cecilio Botella M. 2014. Chronology of the development of the deciduous dentition in Mediterranean population. Forensic Science International 240:95-103.

Jayaraman J, Wong HM, King NM, Roberts GJ. 2013. The French-Canadian data set of Demirjian for dental age estimation: A systematic review and meta-analysis. Journal of Forensic and Legal Medicine 20:373-381.

Jayaraman J RG, King NM, Wong HM. 2012. Dental age assessment of southern Chinese using the United Kingdom Caucasian reference dataset. Forensic Science International 216:68-72.

Johanson G. 1971. Age determination from teeth. Odontologisk Revy 22:121-126.

Kahl B, Schwarze C. 1988. Updating of the dentition tables of I. Schour and M. Massler of 1941. Fortschritte der Kieferorthopadie (Munchen) 49:432-443.

Kappers CUA. 1930. Contributions to the anthropology of the near-East. I. The Armenians. Proceedings of the Royal Academy of Amsterdam 33:792-801.

Karadayi B, Afsin H, Karadayi S, Ozaslan A. 2014. The role and significance of dental development atlas in age estimation [Article in Turkish]. Adli Tip Bulteni 19(2):75-80.

Karadayi B, Afsin H, Ozaslan A, Karadayi S. 2014. Development of dental charts according to tooth development and eruption for Turkish children and young adults. Imaging Science in Dentistry 44:103-113.

159

Karatas OH ÖF, Dedeoglu N, Çolak C, Altun O. 2013. Radiographic evaluation of third-molar development in relation to the chronological age of Turkish children in the southwest Eastern Anatolia region. Forensic Science International 232:238.e231-235.

Kashyap VK, Rao NRK. 1990. A modified Gustafson method of age estimation from teeth. Forensic Science International 47:237-247.

Kasper KA, Austin D, Kvanli AH, Rios TR, Senn DR. 2009. Reliability of third molar development for age estimation in a Texas Hispanic population: a comparison study. Journal of Forensic Sciences 54:651-657.

Kaul S, Saini S, Saxena B. 1975. Emergence of permanent teeth in school children in Chandigarh, India. Archives of Oral Biology 20:587-593.

Kaur B, Singh R. 1992. Physical growth and age at eruption of deciduous and permanent teeth in well- nourished Indian girls from birth to 20 years. American Journal of Human Biology 4:757-766

Keith A. 1927. Report on the human remains. In: Hall HR, Woolley CL, editors. The Ur Excavations I al-'Ubaid. Oxford: Oxford University Press.

Keith A. 1934. Report on the Human Remains. In: Woolley CL, editor. Ur Excavations II. The Royal Cemetery. Publications of the joint expedition of the British Museum and of the University of Pennsylvania to Mesopotamia. p 400-409.

Kharoshah MAA, Almadani O, Ghaleb SS, Zaki MK, Fattah YAA. 2010. Sexual dimorphism of the mandible in a modern Egyptian population. Journal of Forensic and Legal Medicine 17(4):213-215.

Kim C, Hong Y, Han D-H, Hong H-K, Kim Y-N, Bae K-H. 2011. A prospective cohort study on emergence of permanent teeth and caries experience in Korean children. International Journal of Paediatric Dentistry 21(4):254-260.

Kimmerle EH, Baraybar JP. 2008. Skeletal Trauma: Identification of Injuries Resulting from Human Rights Abuse and Armed Conflict. Boca Raton: CRC Press.

Kimmerle EH, Jantz RL, Konigsberg LW, Baraybar JP. 2008. Skeletal estimation and identification in American and East European populations. Journal of Forensic Sciences 53(3):524-532.

Kimmerle EH, Konigsberg LW, Jantz RL, Baraybar JP. 2008. Analysis of age-at-death estimation through the use of pubic symphyseal data. Journal of Forensic Sciences 53(3):558-568.

Kimmerle EH, Prince DA, Berg GE. 2008. Inter-observer variation in methodologies involving the pubic symphysis, sternal ribs, and teeth. Journal of Forensic Sciences 53(3):594-600.

160

Kirzioglu Z CD. 2012. Accuracy of different dental age estimation methods on Turkish children. Forensic Science International 216:61-67.

Kochhar R, Richardson A. 1998. The chronology and sequence of eruption of human permanent teeth in northern Ireland. International Journal of Pediatric Dentistry 8(4):243-252.

Köhler S, Schmelzle R, Loitz C, Püschel K. 1994. Die entwicklung des weisheitszahnes als kriterium der lebensalterbestimmung. Annals of Anatomy 176:339-345.

Komar D. 2003. Lessons from Srebrenica: the contributions and limitations of physical anthropology in identifying victims of war crimes. Journal of Forensic Sciences 48(4).

Krischner H, Krischner M. 1932. Jesidis and (Moslem) Arabs from Iraq, with some remarks on Kurds and Jews. Proceedings of the Royal Academy of Amsterdam 35:218-227.

Kronfeld R. 1935. Development and calcification of the human deciduous and permanent dentition. The Burr 15:18-25.

Kronfeld R. 1935. First permanent molar: its condition at birth and its postnatal development. Journal of the American Dental Association 22:1131-1155.

Kronfeld R. 1935. Postnatal development and calcification of the anterior permanent teeth. Journal of the American Dental Association 22:1521-1536.

Kronfeld R, Schour I. 1939. Neonatal dental hypoplasia. Journal of American Dental Association 26:18-32.

Krumholt L. 1968. Variations in the eruption of the permanent teeth [Article in Danish]. Tandlaegebladet 72(9):818-825.

Krumholt L, Roed-Petersen B, Bindborg JJ. 1971. Eruption times of the permanent teeth in 622 Ugandan children. Archives of Oral Biology 16(11):1281-1288.

Kullman L, Johanson G, Akesson L. 1992. Root development of the lower third molar and its relation to chronological age. Swedish Dental Journal 16:161-167.

Kutesa A, Nkamba EM, Muwazi L, Buwembo W, Rwenyonyi CM. 2013. Weight, height and eruption times of permanent teeth of children aged 4–15 years in Kampala, Uganda. BMC Oral Health 13(15):1-8.

Kuykendall KL. 1996. Dental development in chimpanzees (Pan troglodytes): The timing of tooth calcification stages. American Journal of Physical Anthropology 99:135-157.

161

Kvaal S, Solheim T. 1994. A non-destructive dental method for age estimation. Journal of Forensic Odonto-Stomatology 12:6-11.

Kvaal SI, Kolltveit KM, Thomsen IO, Solheim T. 1995. Age estimation of adults from dental radiographs. Forensic Science International 74:175-185.

Lakshmappa A, Guledgud MV, Patil K. 2011. Eruption times and patterns of permanent teeth in school children of India. Indian Journal of Dental Research 22(6):755-763.

Lamendin H, Baccino E, Humbert JF, Tavernier JC, Nossintchouk RM, Zerilli A. 1992. A simple technique for age estimation in adult corpses: The two criteria dental method. Journal of Forensic Sciences 37(5):1373-1379.

Lampl M, Johnston FE. 1996. Problems in the aging of skeletal juveniles: perspectives from maturation assessments of living children. American Journal of Physical Anthropology 101(3):345-355.

Lan WH. 1971. The Chinese dentition. IV. The eruption time of the permanent teeth in Chinese [Article in Taiwanese]. Yi Xue Hui Za Zhi 70(3):159-165.

Latham KE, Finnegan M, editors. 2010. Age Estimation of the Human Skeleton. Springfield, IL: Charles C. Thomas.

Lavelle CL. 1975. A note on the variation in the timing of deciduous tooth eruption. Journal of Dentistry 3(6):267-270.

Lavelle CLB. 1976. The timing of tooth emergence in four population samples. Journal of Dentistry 4(5):231-236.

Lee MMC, Chan ST, Low WD, Chang KSF. 1965. The relationship between dental and skeletal maturation in Chinese children. Archives of Oral Biology 10:883-891.

Lee MMC, Low WD, Chang FSF. 1965. Eruption of the permanent dentition of southern Chinese children in Hong Kong. Archives of Oral Biology 10:849-861.

Legros C, Magitot E. 1880. The Origin and Formation of the Dental Follicle. Chicago: Jansen, McClurg and Co.

Legros C, Magitot E. 1881. Recherches sur l'Evolution du Follicle Dentaire chez les Mammifères. Paris: Librairie Germer Ballière.

Li G, Ren J, Zhao S, Liu Y, Li N. 2012. Dental age estimation from the developmental stage of the third molars in western Chinese population. Forensic Science International 219:158-164.

Liliequist B, Lundberg M. 1971. Skeletal and tooth development. Acta Radiologica 11:97-112.

162

Liversidge H, Speechly T. 2001. Growth of permanent mandibular teeth of British children aged 4 to 9 years. Annals of Human Biology 28:256-262.

Liversidge HM. 1994. Accuracy of age estimation from developing teeth of a population of known age (0-5.4 years). International Journal of Osteoarchaeology 4:37-45.

Liversidge HM. 2000. Crown formation times of human permanent anterior teeth. Archives of Oral Biology 45:713-721.

Liversidge HM. 2009. Permanent tooth formation as a method of estimating age. Frontiers in Oral Biology 13:153–157.

Liversidge HM, Chaillet N, Mornstad H, Nystrom M, Rowlings K, Taylor J, Willems G. 2006. Timing of Demirjian's tooth formation stages. Annals of Human Biology 33(4):454-470.

Liversidge HM, Dean MC, Molleson TI. 1993. Increasing human tooth length between birth and 5.4 years. American Journal of Physical Anthropology 90:307-313.

Liversidge HM, Molleson T. 2004. Variation in crown and root formation and eruption of human deciduous teeth. American Journal of Physical Anthropology 123:172-180.

Logan WHG, Kronfeld R. 1933. Development of the human jaws and surrounding structures from birth to age fifteen. Journal of the American Dental Association 20:379.

Lucy D, Aykroyd RG, Pollard AM, Solheim T. 1996. A Bayesian approach to adult human age estimation from dental observations by Johanson's age changes. Journal of Forensic Sciences 41(2):189-194.

Lunt RC, Law DB. 1974. A review of the chronology of calcification of deciduous teeth. Journal of American Dental Association 89(3):599–606

Lunt RC, Law DB. 1974. A review of the chronology of deciduous teeth. Journal of American Dental Association 89:872-879.

Maber M, Liversidge HM, Hector MP. 2006. Accuracy of age estimation of radiographic methods using developing teeth. Forensic Science International 159S:S68-S73.

MacLaughlin SM, Bruce MF. 1990. The accuracy of sex identification in European skeletal remains using the Phenice characters. Journal of Forensic Sciences 35(6):1384-1392.

Mani SA, Naing L, John J, Samsudin AR. 2008. Comparison of two methods of dental age estimation in 7-15-year-old Malays. International Journal of Paediatric Dentistry 18:380-388.

163

Maples WR. 1978. An improved technique using dental histology for estimation of adult age. Journal of Forensic Sciences 23:764-770.

Mappes MS, Harris EF, Behrents RG. 1992. An example of regional variation in the tempos of tooth mineralization and hand-wrist ossification. American Journal of Orthodontics and Dentofacial Orthopedics 101:145-151.

Martrille L, Ubelaker DH, Cattaneo C, Seguret F, Tremblay M, Baccino E. 2007. Comparison of four skeletal methods for the estimation of age at death on white and black adults. Journal of Forensic Sciences 52(2):302-307.

Mayhall JT, Belier PL, Mayhall MF. 1978. Canadian Eskimo permanent tooth emergence timing. American Journal of Physical Anthropology 49(2):211-216.

McGregor IA, Thomson AM, Billewicz WZ. 1968. The development of primary teeth in children from a group of Gambian villages, and critical examination of its use for estimating age. British Journal of Nutrition 22:307-314.

McVeigh C. 1999. Variability in Human Tooth Formation: A Comparison of Four Groups of Close Biological Affinity. Doctoral thesis, McMaster University.

Mesotten K, Gunst K, Carbonez A, Willems G. 2002. Dental age estimation and third molars: A preliminary study. Forensic Science International 129:110-115.

Mincer HH, Harris EF, Berryman HE. 1993. The ABFO study of third molar development and its use as an estimator of chronological age. Journal of Forensic Sciences 38:379–390.

Molleson T. 2009. Two Sasanian ossuaries from Bushehr, Iran: Evidence for exposure of the dead. Bioarchaeology of the Near East 3:1-16.

Molleson T, Hodgson D. 2003. The human remains from Woolley's excavations at Ur. Iraq 65:91-129.

Moorrees CF, Fanning EA, Hunt EE, Jr. 1963. Formation and resorption of three deciduous teeth in children. American Journal of Physical Anthropology 21:205-213.

Moorrees CFA, Fanning EA, Edward E. Hunt J. 1963. Age variation of formation stages for ten permanent teeth. Journal of Dental Research 42:1490-1502.

Moslemi M. 2004. An epidemiological survey of the time and sequence of eruption of permanent teeth in 4-15-year-olds in Tehran, Iran. International Journal of Pediatric Dentistry 14(6):432-438.

Müller N. 1990. To Determine the Age of People with Special Attention to Wisdom Teeth. Thesis. Friedrich-Alexander Universitat Erlangan-Nürnberg, Germany.

164

Nanda RS. 1960. Eruption of human teeth. American Journal of Orthodontics 5:363-378.

Nissen HW, Riesen AH. 1964. The eruption of the permanent dentition of chimpanzee. American Journal of Physical Anthropology 22:285-294.

Nizam A., Naing L., N. M. 2003. Age and sequence of eruption of permanent teeth in Kelantan, north-eastern Malaysia. Clinical Oral Investigations 7(4):222-225.

Noble HW. 1974. The estimation of age from the dentition. Journal of the Forensic Science Society 14:215-221.

Nolla C. 1952. The Development of Permanent Teeth. Doctoral dissertation, University of Michigan.

Nolla C. 1960. The development of permanent teeth. Journal of Dentistry for Children 27:254-266.

Nortje CJ. 1983. The permanent mandibular third molar: Its value in age determination. Journal of Forensic Odonto-Stomatology 1:27-31.

Nyström M, Haataja J, Kataja M, Evälahti E, Peck L, Kleemola-Kujala E. 1986. Dental maturity in Finnish children, estimated from the development of seven permanent mandibular teeth. Acta Odontologica Scandinavica 44:193-198.

Nyström M, Ranta R, Kataja M, Silvola H. 1988. Comparisons of dental maturity between the rural community of Kuhmo in northeastern Finland and the city of Helsinki. Community Dentistry and Oral Epidemiology 16:215-217.

Ogihara N, Makishima H, Ishida H. 2009. Geometric morphometric study of temporal variations in human crania excavated from the Himrin Basin and neighboring areas, northern Iraq. Anthropological Science 117(1):9-17.

OIze A, Reisinger W, Geserick G, Schmeling A. 2006. Age estimation of unaccompanied minors. Part II. Dental aspects. Forensic Science International 1595:S65-S67.

Olze A, Bilang D, Schmidt S. 2005. Validation of common classification systems for assessing the mineralization of third molars. International Journal of Legal Medicine 119:22–26.

Olze A, Hertel J, Schulz R, Wierer T, Schmeling A. 2012. Radiographic evaluation of Gustafson’s criteria for the purpose of forensic age diagnostics. International Journal of Legal Medicine 126:615-621.

Olze A, Schmeling A, Taniguchi M. 2004. Forensic age estimation in living subjects: the ethnic factor in wisdom tooth mineralization. International Journal of Legal Medicine 118:170-173.

165

Olze A, Solheim T, Schulz R, Kupfer M, Schmeling A. 2010. Evaluation of the radiographic visibility of the root pulp in the lower third molars for the purpose of forensic age estimation in living individuals. International Journal of Legal Medicine 124:183-186.

Olze A, van Niekerk P, Ishikawa T. 2007. Comparative study on the effect of ethnicity on wisdom tooth eruption. International Journal of Legal Medicine 121:445-448.

Owsley DW, Jantz RL. 1983. Formation of the permanent dentition in Arikara Indians: timing differences that affect dental age estimates. American Journal of Physical Anthropology 61:467-471.

Paewinski E, Pfeiffer H, Brinkmann B. 2005. Quantification of secondary dentine formation from orthopantomograms: A contribution to forensic age estimation methods in adults. International Journal of Legal Medicine 119:27-30.

Parner ET, Heidmann JM, Vaeth M, Poulsen S. 2001. A longitudinal study of time trends in the eruption of permanent teeth in Danish children. Archives of Oral Biology 46(5):425-431.

Peirce CN. 1884. Calcification and decalcification of the teeth. Dental Cosmos 26:449-455.

Penniman TK. 1934. A note on the inhabitants of Kish before the Great Flood. In: Watelin LC, editor. Excavations at Kish. Paris: Librairie Orientaliste Paul Geuthner. p 65-72.

Phenice TW. 1969. A newly developed visual method of sexing the os pubis. American Journal of Physical Anthropology 30(2):297-301.

Pillai PS, Bhaskar GR. 1974. Age estimation from teeth using Gustafson's method—a study in India. Forensic Science 3:135-141.

Postgate JN. 1992. Early Mesopotamia: Society and Economy at the Dawn of History. London: Routledge.

Priyadarshini C, Puranik MP, Uma SR. 2015. Dental age estimation methods: A review. International Journal of Advanced Health Sciences 1(12):19-25.

Qudeimat MA and Behbehani F. 2009. Dental age assessment for Kuwaiti children using Demirjian’s method. Annals of Human Biology 36(6):695-704.

Raiq TT, Ghaib NH, Jabri AA. 2005. Dental maturity and chronological age in a sample of growth hormone deficient patients aged 4-16 years. Iraqi Orthodontic Journal 1(1):51-55.

Rantanen AV. 1967. The age of eruption of the third molar teeth. Acta Odontologica Scandinavica 25:1-86.

166

Rathbun T. 1984. Skeletal pathology from the Paleolithic through the Metal ages in Iran and Iraq. In: Cohen MN, Armelagos GJ, editors. Paleopathology at the Origins of Agriculture. New York: Academic Press. p 137-168.

Rathbun TA. 1982. Morphological affinities and demography of metal-age southwest Asian populations. American Journal of Physical Anthropology 59(1):47-60.

Raxter MH, Ruff CB, Auerbach BM. 2007. Technical note: Revised fully stature estimation technique. American Journal of Physical Anthropology 133(2):817-818.

Raxter MH, Ruff CB, Azab A, Erfan M, Soliman M, El-Sawaf A. 2008. Stature estimation in ancient Egyptians: A new technique based on anatomical reconstruction of stature. American Journal of Physical Anthropology 136(2):147-155.

Robins G, Shute CCD. 1986. Predynastic Egyptian stature and physical proportions. Human Evolution 1:313-324.

Rousset M, Boualam N, Delfosse C, Roberts WE. 2003. Emergence of permanent teeth: Secular trends and variance in a modern sample. Journal of Dentistry for Children 70(3):208-214.

Saukko, P and Knight B. Knight’s Forensic Pathology, Third edition. London: Hodder Arnold.

Saunders E. 1837. The Teeth a Test of Age, Considered with Reference to the Factory Children. London: Renshaw.

Saunders S, DeVito C, Herring A, Southern R, Hoppa R. 1993. Accuracy tests of tooth formation age estimations for human skeletal remains. American Journal of Physical Anthropology 92(2):173-188.

Schmeling A, Garamendi PM, Prieto JL, Landa MI. 2011. Forensic age estimation in unaccompanied minors and young living adults. In: Vieira DN, editor. Forensic Medicine: From Old Problems to New Challenges: InTech, DOI: 10.5772/19261.

Schmeling A, Schmidt S, Schulz R, Olze A, Reisinger W, Vieth V. 2010. Practical imaging techniques for age evaluation. In: Black S, Aggrawal A, Payne-James J, editors. Age Estimation in the Living: The Practitioners Guide. Hoboken: John Wiley and Sons. p 130-175.

Schmidt MS. 2011. Mass grave in Iraqi town held bodies of 40 cabbies. The New York Times. New York.

Schour L, Massler M. 1941. The development of the human dentition. Journal of the American Dental Association 28:1153-1160.

167

Schwartz G, Reid D, Dean M, Zihlman A. 2006. A faithful record of stressful life events preserved in the dental developmental record of a juvenile gorilla. International Journal of Primatology 22:837-860.

Senn DR, Stimson PG. 2010. Forensic Dentistry. Boca Raton: CRC Press.

Shanklin WM, Izzeddin N. 1937. Anthropology of the Near East female. American Journal of Physical Anthropology 22(3):381-415.

Short EM. 1944. Domestic water and dental caries. VI. The relation of fluoride domestic waters to permanent tooth eruption. Journal of Dental Research 23:247-255.

Simpson SW, Kunos CA. 1998. A radiographic study of the development of the human mandibular dentition. Journal of Human Evolution 35:479-505.

Smith BH. 1991. Standards of human tooth formation and dental age assessment. In: Kelley MA, Larsen CS, editors. Advances in Dental Anthropology. New York: Wiley-Liss, Inc. p 143-168.

Smith EL. 2005. A Test of Ubelaker’s Method of Estimating Subadult Age from the Dentition. Master’s Thesis, Indianapolis, IN: University of Indianapolis.

Smith EL. 2010. Age estimation of subadult remains from the dentition. In: Latham KE, Finnegan M, editors. Age Estimation of the Human Skeleton. Springfield, IL: Charles C. Thomas.

Smith TM, Tafforeau P. 2008. New visions on dental tissue research: Tooth development, chemistry, and structure. Evolutionary Anthropology 17:213-226.

Solari AC, Abramovitch K. 2002. The accuracy and precision of third molar development as an indicator of chronological age in Hispanics. Journal of Forensic Sciences 47(3):531-535.

Solheim T. 1993. A new method for dental age estimation in adults. Forensic Science International 59:137-147.

Solheim T, Sundnes PK. 1980. Dental age estimation of Norwegian adults—A comparison of different methods. Forensic Science International 16:7-17.

Soliman NL, El-Batran MM, Abou El-Yazeed M. 2008. Eruptive process of second permanent molar among Egyptian group. Australian Journal of Basic and Applied Sciences 2(4):1120-1128.

Soliman NL, El-Zainy MA, Hassan RM, Aly RM. 2011. Timing of deciduous teeth emergence in Egyptian children. Eastern Mediterranean Health Journal 17(11).

Sołtysiak A. 2006. Physical anthropology and the “Sumerian problem”. Studies in Historical Anthropology 4:145-158.

168

Sołtysiak A. 2008. Short Fieldwork Report: Tell Majnuna (Syria), season 2006. Bioarchaeology of the Near East 2:77-94.

Sołtysiak A. 2008. Short Fieldwork Report: Tell Barri (Syria), seasons 1980–2006. Bioarchaeology of the Near East 2:67-71.

Sołtysiak A. 2008. Short Fieldwork Report: As-Sabiyah and Al-Khuwaysat (Kuwait), seasons 2007–2008. Bioarchaeology of the Near East 2:103-107.

Sołtysiak A. UNK. Editorial. Bioarchaeology of the Near East 1:1-3.

Sołtysiak A, Mahfroozi A. 2008. Short Fieldwork Report: Gohar Tepe and Goldar Tepe (Iran), seasons 2006–2007. Bioarchaeology of the Near East 2:71-77.

Sołtysiak A, Tomczyk J. 2008. Short Fieldwork Report: Tell Masaikh (Syria), seasons 1998-2007. Bioarchaeology of the Near East 2:94-97.

Sołtysiak A, Tomczyk J. 2008. Tell Ashara (Syria), Seasons 1999-2007.

Sołtysiak A, Tomczyk J. 2008. Short Fieldwork Report: Jebel Mashtale and Tell Marwaniye (Syria), seasons 2005–2006. Bioarchaeology of the Near East 2:97-99.

Steele C, Malin-Boyce S, Hines DZC. 2005. Forensic investigation of a mass grave complex, Muthanna province, Iraq. In: Trimble MK, editor. Mass Graves Investigations. St Louis, MO: United States Army Corps of Engineers.

Steggerda M, Hill TJ. 1942. Eruption time of teeth among Whites, Negroes, Indians. American Journal of Orthodontics and Oral Surgery 28:361-370.

Steyn M, Patriquin ML. 2009. Osteometric sex determination from the pelvis—Does population specificity matter? Forensic Science International 191(1-3):113.e111-113.e115.

Stuart H et al. 1939. Studies from the Center for Research in Child Health and Development. I Monographs of the Society for Research in Child Development: School of Public Health, Harvard University.

Suri L, Gagari E, Vastardis H. 2004. Delayed tooth eruption: Pathogenesis, diagnosis, treatment. A literature review. American Journal of Orthodontics and Dentofacial Orthopedics 126:432-445.

Swindler DR. 1956. A Study of the Cranial and Skeletal Material Excavated at Nippur. Philadelphia: The University Museum, University of Pennsylvania.

Tanner JM. 1962. Growth at Adolescence. Oxford: Blackwell.

169

Tompkins RL. 1996. Human population variability in relative dental development. American Journal of Physical Anthropology 99:79-102.

Townsend N, Hammel EA. 1990. Measurement issues for developing country-demography: age estimation from the number of teeth erupted in young children: an aid to demographic surveys. Demography 27(1):165-174.

Tyagi R, Khuller N, Sharma A, Khatri A. 2008. Genetic basis of dental disorders: a review. Journal of Oral Health and Community Dentistry 2(3):55-61.

Ubelaker DH. 1978. Human Skeletal Remains. Chicago: Aldine.

Ubelaker DH. 1987. Estimating age at death from immature human skeletons: an overview. Journal of Forensic Sciences 32(5):1254-1263.

Ubelaker DH. 1989. Human Skeletal Remains. 2nd edition. Washington D.C.: Taraxacum.

Ubelaker DH, Volk CG. 2002. A test of the Phenice method for the estimation of sex. Journal of Forensic Sciences 47(1):19-24.

Uysal T, Sari Z, Ramoglu SI, Basciftci FA. 2004. Relationships between dental and skeletal maturity in Turkish subjects. Angle Orthodontist 74:657-664.

Wada Y. 1994. A discriminant function for sex determination of ancient Iraqis based on radial measurements. Anthropological Science 102:149-158.

Wedl JS, Danias S, Schmelzle R, Friedrich R. 2005. Eruption times of permanent teeth in children and young adolescents in Athens (Greece). Clinical Oral Investigations 9(2):131-134.

Wedl JS, Schoder V, Friedrich R. 2004. Tooth eruption times of permanent teeth in male and female adolescents in Niedersachsen [Article in German]. Archiv für Kriminologie 213(3-4):84-91.

Willems G, Vanolmen A, Spiessens B, Carles C. 2001. Dental age estimation in Belgian children: Demirjian technique revisited. Journal of Forensic Sciences 46:893-895.

Winkler LA, Schwartz JH, Swindler DR. 1996. Development of the orangutan permanent dentition: Assessing patterns and variation in tooth development. American Journal of Physical Anthropology 99:205-220.

Wise GE, Frazier-Bowers S, D'Souza RN. 2002. Cellular, molecular, and genetic determinants of tooth eruption. Critical Reviews in Oral Biology and Medicine 13(4):323-334.

Wolanski N. 1966. A new method for the evaluation of tooth formation. Acta Genetica 16:186-197.

170

Xiaohu X, Philipsen HP, Jablonski NG, Pang KM, Jiazhan Z. 1992. Age estimation from the structure of adult human teeth: review of the literature. Forensic Science International 54:23-28.

Yeung C, Chu C. 2014. A review of the eruption of primary teeth. OA Dentistry 2(1):7.

Yun DJ. 1957. Eruption of primary teeth in Korean rural children. American Journal of Physical Anthropology 15:261-268.

Zakrzewski SR. 2003. Variation in ancient Egyptian stature and body proportions. American Journal of Physical Anthropology 121(3):219-229.

Zeng DL, Wu ZL, Cui MY. 2010. Chronological age estimation of third molar mineralization of Han in southern China. International Journal of Legal Medicine 124:119-123.

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BIOGRAPHICAL SKETCH

David Hines has worked extensively on mass graves issues in Iraq and Bosnia

and Herzegovina. After earning his Master of Arts degree in anthropology in 2005, he

was active in the recovery of mass graves in Iraq for the Mass Graves Investigation

Team, operating for the Regime Crimes Liaison Office, under the Department of Justice

and the Department of State. He returned to Iraq in 2010 to train and mentor Iraq’s own

mass graves teams as part of the Iraq mission of the International Commission on

Missing Persons (ICMP), and later worked as a senior forensic anthropologist for the

ICMP in Bosnia and Herzegovina. He is the founder of OsCoxa, LLC, a physical

anthropology consulting company providing service to cultural resource management

firms. He received his Ph.D. in anthropology from the University of Florida in 2016.