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Orthodontics Part IOrthodontics Part I

Paul K. Chu, DDS

22 NOV 2010

REVIEW FROM LAST LECTUREREVIEW FROM LAST LECTURE

So a 0.05% NaF daily rinse (ACT) has how much mg fluoride per mL?

Step 1Step 1-- Convert to F ion.Convert to F ion.*** % NaF x 0.45 = %F ion****** % NaF x 0.45 = %F ion***0.05% x 0.45 = 0.0220 % F0.05% x 0.45 = 0.0220 % F-- ionion

Step 2Step 2-- Convert % FConvert % F-- ion to ppmion to ppm***%F ion x 10***%F ion x 1044= ppm F***= ppm F***0.0220% x 100.0220% x 104 4 = ~220 ppm F ion= ~220 ppm F ion

REVIEW FROM LAST LECTUREREVIEW FROM LAST LECTURE

Step 3 Convert ppm F ion to mg/mL

*** ppm = mg/L ***

220 ppm F ion = 220mg/Lpp g

We want denominator to be mL, so with stoichiometry …

220 mg X 1 L = 0.22 mg/mL

L 1000mL

In the ABPD review book it’s 0.022 !!!

FROM THE ABPD REVIEW FROM THE ABPD REVIEW BOOK BOOK

EE--MAIL FROM DR. ADAIR MAIL FROM DR. ADAIR 10/01/200510/01/2005

OK, I think I see where the error is - it's in the table at the top of page 18, where the concentration is given as "0.022" under the

l h d d "M F i L " Tcolumn headed "Mg F ion per mL, cc, or g." Two other places in that section, it's given correctly. I'll make sure the typo is corrected in the nextedition. Thanks.

Steve

July 01, 2003July 01, 2003yy

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My first day as a Pedo My first day as a Pedo ResidentResident

CONFUSING???CONFUSING???

As much as you don’t want to As much as you don’t want to learn Ortho…you learn Ortho…you MUSTMUST be be

competent is its basics.competent is its basics.

7/1999 3/2002

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PHASE 1:

$1500.00

PHASE 2:

$4000.00 -$7000.00

DIAGNOSISDIAGNOSISDIAGNOSISDIAGNOSIS

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INTRODUCTIONINTRODUCTION

Sequence of Calcification of Primary Teeth

Central Incisor (#a) 14 weeks in utero

First Molar (#d) 15 weeks in uteroFirst Molar (#d) 15 weeks in utero

Lateral Incisor (#b) 16 weeks in utero

Cuspid (#c) 17 weeks in utero

Second Molar (#e) 18 weeks in utero

A BCD

E

AB

C

D

E

12345

678

Positioning of Primary Teeth

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Facial TypesFacial Types

Straight Protrusive Retrusive

Typical Child Profile

Rule of ThirdsRule of Thirds Class I OcclusionClass I Occlusion

MB CUSP of Upper 6 occludes with B Groove of lower 6

Class 1Class 1-- MalocclusionMalocclusion

l Cl Molars - Class I

Anterior crowding

Class 2 Class 2 --MalocclusionMalocclusion

Class II

Retrognathic profile Retrognathic profile

In this case, it is a FULL cusp Class II

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Class 2 MalocclusionClass 2 Malocclusion-- Division 1Division 1

Class II Molars

BUCALLY FLARED BUCALLY FLARED Incisors

Class 2 MalocclusionClass 2 Malocclusion-- Division 2Division 2

Class 2 Division 2 Incisors RETROCLINED

Class 3 Class 3

Prognathic mandible

In this case, we have a FULL CUSP Class 3

Classification of Occlusion of the Primary Second Molar

Flush terminal plane

Mesial step

Look at the distal aspect of the 2nd molar

es a step

Distal step

Flush Terminal Plane Flush Terminal Plane

-Historically seen as ‘normal’

-observed 30%

Distal Mesial

Mesial Step

MS of 1 mm observed 40%

MS >1mm observed 20%

Distal Mesial

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Distal Step

Distal M i l

DS of 1 mm observed 10%

Distal Mesial

PERCENTAGES:PERCENTAGES:Relation of primary 2Relation of primary 2ndnd molar relation to molar relation to

permanent molar occlusion*permanent molar occlusion*

56% Class I; 44% Class II

(1mm) 76% CI; 23% CII; 1% CIII

(≥2mm) 68% CI; 13%CII; 19%CIII

Class II- 99.999999%

*Bishara, et. Al- “Facial & Dental Changes in Adolescents & Their Clinical Implications (2000)

PERCENTAGES:PERCENTAGES:Relation of Spacing/Crowding in the Primary Relation of Spacing/Crowding in the Primary

Dentition to Permanent DentitionDentition to Permanent Dentition

1o Spacing ≥ 6mm= no crowding

1o Spacing 3-6mm =20% crowding

1o Spacing < 3mm 50% crowding

1o No Spacing = 66% crowding

1o Crowding = 100%

Primary CrowdingPrimary Crowding

Almost 100% chance Almost 100% chance of permanent crowding

No SpacingNo Spacing

66% chance of 66% chance of crowding in the permanent denition

Spacing 3-6 mm=

FairFair-- to Good Spacingto Good Spacing

Spacing 3 6 mm 20% chance of crowding

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Good Spacing!!Good Spacing!!

1o Spacing ≥ 6mm= no crowding

Primate SpacePrimate Space

-Primate spaces occur in about 50% of children.

-Maxilla: lateral incisor and the upper canine.

-Mandible: between the lower canine and the deciduous first molar.

Leeway SpaceLeeway Space

Measures mesial distal width of primary CDE and compares to analogous succeedaneous 3-4-5

Sum of (c-d-e) > (3-4-5) This allows more space for 3-4- This allows more space for 3 4

5 This "leeway space" averages

1.7 mm. in the mandibular buccal segment; 0.9 in the maxillary buccal segment

Early Mesial ShiftEarly Mesial Shift

occurs when the 1st permanent molars erupt (5 5 6 5 years)erupt (5.5-6.5 years) and cause a mesial shift into the primate space.

Late Mesial ShiftLate Mesial Shift

FTPMolar moves into

this space... Class I

Ugly Duckling StageUgly Duckling Stage

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OTHER NORMSOTHER NORMS

Overbite is a vertical measurement of the amount of overlap of the incisors. Overjet is the millimeter horizontal measurement from the labial of the maxillary central incisor to the labial of the mandibular central incisor.

Overjet = 0-4mm

Overbite= 10-40%

6 e d c 2 1

6 d 2 1

1 2 c d e 6

1 2 d 6

Definition of a Mixed Dentition

6 e d c 2 1 1 2 c d e 6

Incisor Liability Incisor Liability

•Permanent incisors are larger than primary incisors

•This difference in size is termed "incisor liability"liability

•**In the maxilla, the difference is 7.6 mm. In the mandible, the difference is 6.0 mm. **

•How does the body create enough room for the larger, permanent incisors?

Ways to Overcome Incisor Ways to Overcome Incisor Liability Liability

Interdental spacing of primary incisors Intercanine arch width growth Labial positioning of the permanent incisors Favorable size ratio between the primary and

permanent incisors

Good interdental spacing of primary incisors allows for better alignment of the larger permanent incisors.

Primary Spacing Primary Spacing Intercanine arch width growth Intercanine arch width growth

– width growth creates more room for the permanent incisors

– mandibular intercanine th tlgrowth occurs mostly

during permanent incisor eruption

– maxillary intercanine growth occurs during incisor eruption, and continues

– unpredictable

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Labial positioning of the Labial positioning of the permanent incisors permanent incisors

– permanent incisors erupt to a more labial position

– permanent incisors are angled more labially

– this all creates more arch length

Favorable size ratio between the Favorable size ratio between the primary and permanent incisors primary and permanent incisors

– size ratio between the primary and permanent p y pincisors may be favorable or unfavorable

– favorable: large primary, small permanent

– unfavorable: small primary, large permanent

What is Arch Length?What is Arch Length?

Arch length is the distance in millimeters from the mesial of the 1st permanent molar around the arch over the contact points to thearch over the contact points to the mesial of the 1st permanent molar on the opposite side.

What is the BEST predictor of What is the BEST predictor of saggital relationship insaggital relationship insaggital relationship in saggital relationship in permanent dentition?permanent dentition?

Primary Canine RelationshipPrimary Canine Relationship

Look at long axis of the maxillary cuspid

N t id (Cl I) Neutro cuspid (Class I)

Disto cuspid (Class II)

Mesio cuspid (Class III)

Neutro Cuspid

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Disto Cuspid

- Class II

Mesio Cuspid

Neutro/Slight MS= Class I

Excessive MS= Class III

AnalysisAnalysis

Use of techniques to predict spacing

During the mixed dentition

Moyer’s Analysis Step BY StepMoyer’s Analysis Step BY Step

STEP 1:– a) Measure mesial - distal widths of mnd

incisors– b) Measure space of anterior segment available– Subtract B from A– Negative number indicates less space is

available

Moyer’s Analysis Step BY StepMoyer’s Analysis Step BY Step

STEP 1:

Negative number– Negative number indicates less space is available

Moyer’s Analysis Step BY StepMoyer’s Analysis Step BY Step

STEP 2:– a) Measure space available for 3-4-5 on each side ) p

of the arch (distal of lateral incisor to mesial of 1st

molar)– b) Calculate from prediction table the size of 3-4-5

(using the measured sized of the mandiublar incisors that we used in Step 1)

– Subtract B from A

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Moyer’s Analysis Step BY StepMoyer’s Analysis Step BY Step

STEP 2:

– Calculate from di ti t bl th iprediction table the size

of 3-4-5

– This is the Moyers Prediction table

– Uses Md Incisors as measuring ‘guides’

Moyer’s Analysis Step BY StepMoyer’s Analysis Step BY Step

STEP 2:

– In our case, we had 23.0 mm

We meas re space– We measure space available as 20.1 & 19.5 per side (for our example)

– what is our predicted Mandibular 3-4-5 space needed?

Moyer’s Analysis Step BY StepMoyer’s Analysis Step BY Step

STEP 2:– In our case, we had

23.0 mmW– We measure space available as 20.1 & 19.5 per side

– what is our predicted Mandibular 3-4-5 space needed?

Moyer’s Analysis Step BY StepMoyer’s Analysis Step BY Step

STEP 2:

Subtract tooth size from space available on left and right

At this point, you should have three numbers:– number for incisor crowding or excess space

– number for right buccal segment crowding or excess

Moyer’s Analysis Step BY StepMoyer’s Analysis Step BY Step

number for right buccal segment crowding or excess space

– number for left buccal segment crowding or excess space

Add the three numbers: negative = crowding, positive = space

Add ‘em up!!Add ‘em up!!

(-2.1) + (-3.2) + (-2.7) = (-8.0)

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If we measured mandibular incisors, and their added mesio-distal width is 21.9

h t i th

Anyone…..Anyone…..

mm, what is the expected width (using Moyers Analysis) of the maxillary 3 – 4 –5’s?

Tanaka Johnson AnalysisTanaka Johnson Analysis

MUCH EASIER!!!!

Mx: add 11 5mm to Mn incisal Mx: add 11.5mm to Mn incisal measurement= Mx buccal segment requirements

Mn: add 10.5 mm to Mn incisal= Mn buccal segment requirements

IDEAL PRIMARY OCCLSUIONIDEAL PRIMARY OCCLSUION

FTP/ Mesial step molars + Canines FTP/ Mesial step molars + Canines Generalized primate spacing 2 mm OJ 2mm OB Ovoid Arches

ReferencesReferences

Board Review Handbook: 2009 ABPD

Bishara et Al. “Facial and dental changes in adolescents and their clinical implications.” Angle Orthod. 2000 Dec;70(6):471-83. ( )

www.uic.edu

http://cudental.creighton.edu