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BOSTON UNIVERSITY
INSTITUTE FOR DENTAL RESEARCH AND EDUCATION
THESIS
PREVALENCE OF ATTRITION IN MIXED DENTITION IN
SCHOOL CHILDREN OF ABU-DHABI, UAE
DR. AFRA ALI ABDULLA FADHEL AL MEMARI
Submitted in partial fulfillment of the requirements for the degree of
MASTER OF SICENCE IN PEDIATRIC DENTISTRY
2012
ii
ACKNOWLEDGMENT
First, I would like to express my appreciation and thankfulness for Allah, the Most
Gracious, and the Most Merciful, for all the strength and blessings to successfully complete
my thesis and crossing my faith with the dedicated people who supported me.
Many thanks to my parents for their continuous support which is extended from my
childhood till my Master Degree. My deepest appreciation goes to my bother Eng. Saoud
Al-Maamari and my sister Amna Al-Maamari for their considerable support, and wide
knowledge who did not hesitate to participate directly to my thesis, and my other siblings for
their positive attitudes.
My deep gratitude and admiration is expressed to my direct mentor Dr. Abeer
Basunbul (program director), and my indirect mentors Dr. Harold Goodis, and Dr. Sami
Chogle and Dr. Maria Orellana, for exposing me to their knowledge and experience and to
Dr. Manal Al Halabi.
My deepest gratefulness to Abu Dhabi Education Council for granting me the
opportunity to complete my thesis.
I would also extend my appreciation to those people who helped and supported me
during the completion of my research.
Lastly, my genuine appreciation is dedicated to Dr. shaimaa Al Kayoumi, this thesis
could have not been completed without her care, assistance, and encouragement.
iii
DEDICATION
To my blessed parents, who have taught me how to appreciate, possess and apply
knowledge I have learnt.
To my source of inspiration, Dr. Abeer Basumbul.
To my supportive coachs Dr. Harold Goodis and Dr. Sami Chogle, and Mariya Orellana for
the superior knowledge gained.
To my brother Eng. Saoud Al-Maamari and my sister Amna for their support.
To my closest friend Dr. Shaimaa Al Kayoumi for her assistance and care.
iv
ABSTRACT
Objective: To measure the prevalence and severity of dental attrition and evaluate the
difference between private and government schools, boys and girls, in mixed dentition
school children of UAE.
Methods: An epidemiological cross-sectional survey was conducted by trained, calibrated
examiners using the smith and knight scale. The cluster sample consisted of 371 children
(168 boys, 203 girls) attending 4 schools (2 private, 2 governments) selected in different
regions of Abu Dhabi. Data was collected by clinical examinations performed outdoors
under natural light, and using a dental mirror and probe. The data analysis consisted of
Multi-linear regression analysis, ANOVA, Kppa and Kindall’s Tau-b.
Results: school children attrition prevalence was 50.7%, attrition severity was 26.24% and
DFT scores were 30.09%.
Conclusion: Attrition prevalence and severity is significantly higher in the government than
in private schools, while there was no difference in the attrition prevalence between girls and
boys. A statistically significant relation found between attrition prevalence and severity in
type of school, right canine classification, and number of siblings.
v
Table of Contents
ACKNOWLEDGMENT.......................................................................................................... ii
DEDICATION ........................................................................................................................ iii
ABSTRACT ............................................................................................................................ iv
List of tables .......................................................................................................................... viii
List of figures .......................................................................................................................... ix
I. INTRODUCTION ............................................................................................................ 1
II. REVIEW OF LITERATURE ........................................................................................... 3
Etiology .................................................................................................................................... 3
Bruxism .................................................................................................................................... 4
Tempromandibular Joint Disorder ........................................................................................... 6
Occlusion ................................................................................................................................. 8
Diet ........................................................................................................................................... 8
Salivary flow rate ................................................................................................................... 10
Medical conditions ................................................................................................................. 11
Tooth brush and tooth paste Oral Hygiene products ............................................................. 12
Management ........................................................................................................................... 13
III AIMs ........................................................................................................................... 15
IV MATERIALS AND METHODS ................................................................................ 16
IRB Approval and Sample Collection ................................................................................... 16
Inclusion and Exclusion Criteria ............................................................................................ 18
vi
Inter-examiner Calibration and Preparation for School Visit ................................................ 20
DFT scores ............................................................................................................................. 21
V. DATA ANALYSIS ........................................................................................................ 22
VI. RESULTS ................................................................................................................... 25
Responses to the Questionnaire ............................................................................................. 25
Parents related information .................................................................................................... 25
Education ............................................................................................................................... 25
Employment ........................................................................................................................... 27
Childs related information ..................................................................................................... 28
Variables on children habits: ................................................................................................. 29
Dietary habits ......................................................................................................................... 31
Oral Hygiene Practices .......................................................................................................... 32
Prevalence of attrition in private versus government schools ............................................... 34
Significant variables............................................................................................................... 37
Attrition prevalence ............................................................................................................... 37
Attrition severity .................................................................................................................... 38
Primary canine attrition severity and classifications ............................................................. 42
DFT% ..................................................................................................................................... 43
Other variables ....................................................................................................................... 45
Attrition variables .................................................................................................................. 45
DFT% variables ..................................................................................................................... 46
vii
VII. DISCUSSION ............................................................................................................. 48
VIII. CONCLUSION ........................................................................................................... 55
LIMITATIONS AND FUTURE RRECOMMENDATIONS ............................................... 57
REFERENCES ...................................................................................................................... 58
APPENDEX ........................................................................................................................... 70
A- School consent form ................................................................................................ 70
B- Participant consent form.......................................................................................... 71
C- Questionnair form ................................................................................................... 74
D- Examination form ....................................................................................................... 77
viii
List of tables
Table 1: Drug groups which are related to salivary hyposecretion ....................................... 11
Table 2: Groups of patients at risk of developing excessive tooth wear. .............................. 12
Table 3: Tooth Criteria classification with accordance to smith and knight scale ................ 17
Table 4: Inclusion and Exclusion Criteria for participants .................................................... 18
Table 5: Questionnaire general layout ................................................................................... 19
Table 6: Intra-examiner calibration of examiner A ............................................................... 22
Table 7: Intra-examiner calibration of examiner B ................................................................ 23
Table 8: Inter-examiner calibration first examination by A followed by B .......................... 23
Table 9: Inter-examiner calibration first examination by B followed by A .......................... 24
Table 10: Demonstrative data for the relationship between prevalence and type of school,
for models (Regression) and (Residual) ................................................................................ 37
Table 11: Dependent Variable: attrition Prevalence .............................................................. 37
Table 12: Predictors: (Constant), Rcan, Rmol, school, Number ........................................... 41
Table 13: Dependent Variable: attrition severity ................................................................... 42
Table 14: Mean, Median, and Standard deviation values of the attrition prevalence and
severity. .................................................................................................................................. 42
Table 15: DFT% significant variables ................................................................................... 44
Table 16: Mean, median and standard deviation values of DFT% ........................................ 45
Table 17: Attrition excluded variables ................................................................................... 46
Table 18: DFT% excluded variables...................................................................................... 47
ix
List of figures
Figure 1: Demonstration of tooth criteria classification as specified in Table 3 ................... 17
Figure 2: Sample size layout .................................................................................................. 20
Figure 3: Father’s educational level ....................................................................................... 26
Figure 4: Mother’s educational level ..................................................................................... 26
Figure 5: Father’s professional level...................................................................................... 27
Figure 6: Mothers’ professional level .................................................................................... 28
Figure 7: children related variables........................................................................................ 29
Figure 8: Overall comparison between private and Governmental schools .......................... 29
Figure 9: Comparison between Habits adapted by participants in both private and
governmental schools............................................................................................................. 30
Figure 10: Frequency of video games played ........................................................................ 30
Figure 11: Consumption of Carbonated drinks per week ...................................................... 31
Figure 12: Consumption of fruit based drinks per week........................................................ 32
Figure 13: Consumption of fresh fruit cuts per week ............................................................ 32
Figure 14: Teeth brushing frequency on daily basis .............................................................. 33
Figure 15: Tooth brush type ................................................................................................... 33
Figure 16: Tooth paste type ................................................................................................... 34
Figure 17: attrition prevalence according to school category ................................................ 35
Figure 18: attrition prevalence scores according to school category ..................................... 35
Figure 19: attrition severity score according to school category ........................................... 36
Figure 20: attrition prevalence according to gender .............................................................. 36
Figure 21: attrition prevalence according to teeth ................................................................. 38
Figure 22: Attrition scores frequency .................................................................................... 39
x
Figure 23: Upper dental arch ................................................................................................. 39
Figure 24: Lower dental arch ................................................................................................. 40
Figure 25: Attrition prevalence according to segments ......................................................... 40
Figure 26: Attrition severity according to segments .............................................................. 41
Figure 27: DFT% according to school category .................................................................... 43
Figure 28: DFT% according to brushing frequency .............................................................. 44
Figure 29: DFT% according to mother’s educational level ................................................... 44
1
I. INTRODUCTION
Attrition is defined as loss of the tooth structure or restoration and it can be induced by the
masicatory forces or the contact of the teeth against each other and the interproximal
surfaces. It mostly affects occlusal and incisal surfaces, also slightly at the contact points [1].
The affected teeth are characterized as flat, round or sharply angled with polished surfaces
on the occlusal or incisal areas of the teeth and may be the result of excessive attrition of one
tooth against the other [2]. Erosion is a very important contributing factor to the loss of tooth
substance by attrition.
Dental attrition is an increasing dilemma that has been noticed by dentists, in which
grinding is the possible cause. The grinding process is an oral sign of bruxism and bruxism
is a Greek word meanings “vrigmos o’dodon” that includes grinding and clenching [3] The
American Academy of Orofacial Pain defines bruxism as “ a diurnal or nocturnal
parafunctional activity including clenching, bracing, gnashing and grinding of the teeth”
while the American Sleep Disorders Association defines it as “ tooth grinding or clenching
during sleep plus one of the following: tooth wear, sounds or jaw muscle discomfort in the
absence of a medical disorder”.
Local/mechanical factors, systemic/ neurological factors and psychological factors
like sleep confusion associated with dreams at night, day time emotional expression,
concern induced responses or the anticipation of worrying situations (anxiety and stress)
appear to be the contributors of bruxism and affects 15% to 100% of the population.4 7% to
15.1% is the prevalence range of bruxism in children 5-7 with a few studies confirming
higher rates in girls than boys [8].Consequences of bruxism includes: loss of tooth structure
that can range from mild to severe either localized or generalized [14], thermal
2
hypersensitivity, tooth hypermobility, hypercementosis, fractured cusps, pulpitis, pulp
necrosis [15], muscular pain, degenerative tempromandibular joint disease, muscular
hypertrophy, headache and periodontal tissue injury [4].
Management of bruxism includes: occlusal adjustment of dentition, use of
interocclusal appliances [9], behaviour modification [10], and pharmaceuticals [11].
According to Hachmann and McDonald and others [12], patients suffering from bruxism
may use a bite plate covering the occlusal surfaces of all teeth to prevent the continuous
attrition [13]. Allergic diseases are considered as systemic contributors to the bruxism.
Patients should be referred to a specialist to treat the problem when seen [13].
3
II. REVIEW OF LITERATURE
Etiology
Multiple factors causes’ dental attrition, parafunction is one of the most common
factors. Clinical observations and data from previous literature indicates that malocclusion,
iatrogenic factors, and increased psycho emotional stress are the predisposers to functional
disorder of the masticatory system, especially Temporo Mandibular Joint (TMJ)
dysfunctions and bruxism. There are different studies in previous literatures, which have
related the various intrinsic, and extrinsic factors for bruxism and dental attrition including
psychological factors, occupation, diet etc [16]. In younger populations greater awareness is
needed to control attrition as diets increase in acidity, and snacking frequency on both acidic
and sugary foods continues to increase [17]. The higher susceptibility of the deciduous
dentition to tooth wear has rather been attributed to the reduced thickness and softness of the
enamel to its greater solubility in acid [27, 28]. Deciduous teeth are smaller than permanent
teeth, enamel is softer, and there are morphological differences compared to permanent
teeth, therefore, the erosive process reaches the dentine earlier and leads to an advanced
lesion after a shorter exposure to acids, compared with permanent teeth. Common sites for
dental erosion in primary teeth are the occlusal aspects of the molars and the palatal surfaces
of the upper incisors. [37] Several studies have investigated that malocclusion and
orthodontic treatment have been variably associated with this condition. Tooth wear is
influenced by the way the mandibular teeth contact the maxillary teeth [21].
4
Bruxism
Bruxism is defined as the habitual nonfunctional mandibular movement with forceful
contact between occlusal tooth surfaces, which is uncontrolled. Excessive grinding,
clenching or friction of teeth that can lead to several dental, oral, and facial complications
[18, 20]. Bruxism is defined by the American Academy of Orofacial Pain as: “A diurnal or
nocturnal parafunctional activity including clenching, bracing, gnashing and grinding of the
teeth” [4]. The American Academy of Sleep Medicine defines bruxism as a stereotyped oral
motor disorder characterized by sleep related grinding and/or clenching of the teeth, whereas
the American Academy of Orofacial Pain extends the definition to the same movements that
occur during wakefulness. There is a considerable amount of literatures suggesting that sleep
and a wake bruxism are 2 different disorders with a different etiopathogenesis. Sleep
bruxism is characterized by both a grinding type and a clenching type activity and is
associated with complex micro arousal phenomena occurring during sleep, the
pathophysiology of which is yet to be clarified, whereas awake bruxism is characterized by a
clenching type activity and is associated with psychosocial factors and a number of
psychopathological symptoms [23], its etiology is still controversial but the multifactorial
cause has been recognized, including pathophysiologic, psychologic and morphologic
factors. Moreover, masticatory neuromuscular system immaturity can lead to bruxism in
younger children [18]. Bruxism may also be caused by allergic processes such as asthma and
respiratory airway infection and is also linked to diseases such as basal ganglia infarction,
cerebral palsy, Down syndrome, epilepsy, Leigh disease, meningococcal septicemia,
multiple system atrophy, gastro esophageal reflux, and Rett syndrome. In addition to
5
hyperactivity, which is associated with bruxism due to the effect of the am, pheta mines
which are used for the management of attention deficit hyperactivity disorder [33]. Oral
habits such as thumb sucking, onicofagy, object biting etc can be usual and happen
temporarily. However, when they surpass a physical tolerance, the system may collapse and
harm the person’s health. According to Cheifetz et al, the fact that children without any oral
habits present a higher prevalence of bruxism suggests that this parafunction can also be an
alternative method to relieve stress [39].
Wear of the teeth is the most commonly mentioned sign of bruxism although there is
considerable argument about the correlation between bruxism and tooth wear. Investigators
have different suggestions on bruxism and its association with attrition. Schneider and
Peterson reported 15% of children demonstrate tooth wear due to bruxism. Marbach et al
reported that only 34.4% of the self reported bruxers in their study showed evidence of tooth
wear. The authors noted that evidence of tooth wear did not essentially indicate bruxing.
According the American Sleep Disorders Association the diagnosis of sleep bruxism is
based on the report of tooth grinding or clenching in combination with at least one of the
following signs: abnormal tooth wear, sounds associated with bruxism, and jaw muscle
discomfort they also consider the presence of tooth injury as one of the criteria for severe
bruxism, the association between severity of bruxism and tooth damage is not yet
established. Sleep bruxism has prevalence in the general adult population from 10- 20%.
Reported prevalence in children ranges from 7-15.1%, with girls apparently more frequently
affected. It is also reported in up to 20% of children younger than 11 years of age. This is
probably an underestimate and may indicate only clinically significant bruxism. The
prevalence decreases with age. Obstructive sleep apneas resulting in frequent arousals in
6
children have been correlated with problems in behavior regulation, attention, and executive
functioning [19, 20, 22, 24].
The specificity and clinical validity of tooth wear as an indicator of bruxism has been
questioned. The observation of tooth wear is subjective, and no correlation has been
demonstrated between degree of tooth wear and level of electromyography (EMG) bruxism
activity. In addition, several studies imply that tooth wear is a natural observable fact
associated with aging. In summary, the multifactorial cause of tooth wear, the difficulties of
measuring tooth wear, and the natural complex activity pattern of bruxism all complicate the
correlation of tooth wear and bruxism [19].
Tempromandibular Joint Disorder
Temporomandibular joint (TMJ) pain is an uncommon complaint in children.
Etiologic factors suggested as contributing to the development of tempromandibular disease
(TMD) include congenital abnormalities, temporomandibular disorders, infections,
connective tissue disease (CTD), trauma, occlusal factors, parafunctional habits such as
bruxism, nail biting, and non nutritional sucking, head posture and others. Three main
TMDs appear to be more common in chidren: opening limitation, mandibular deviation and
movement difficulty. The incidence of TMD symptoms is increasing from the primary
dentition to the mixed dentition and is often due to great changes in occlusion and TMJ. The
prevalence of TMD is 16% in children with primary dentition and 90% in children with
mixed dentition. One study of the primary dentition reported 34% of patients with signs
and/or symptoms of TMD. An epidemiological study of 4724 children aged 5-17 years
reported 25% with symptoms. Clicking was seen in 2.7% of children in the primary
dentition and 10.1% in late mixed dentition and further increased to 16.6% in patients with
7
permanent dentition. A similar study in pre-school children found clicking affects girls more
than boys. For Bonjardim et al. the majority of the symptoms in adolescents were mild, and
girls were more affected, probably due to the result of biologic variables (e.g., hormonal
characteristics), as maturation in girls typically occurs earlier than in boys. In general, the
prevalence of signs and symptoms of TMD is lower in children compared to adults and is
even less in younger child but increases with increasing age. There is variation in the
literature about relationship between TMD and Bruxism in children and adolescence.
Bruxism was not considered related to signs and symptoms of TMD in young children in
some surveys on the other hand a number of studies showed that there is significant
relationship between attrition, symptoms of TMD and deviation on opening and there was
also a significant association between bruxism and most of the TMD signs and symptoms in
children. Controversy also found in the association between tooth wear and TMD in young
children. A variety of psychological and behavioral characteristics are exhibited by TMD
patients such as increased somatization, stress, anxiety and depression. It has been
mentioned that TMD and bruxism are more likely to grow in populations with high anxiety
level, which is one of the main factors in bruxism development. The cause and relationship
between TMD and bruxism has not been established yet. According to the literature, tooth
wear is more likely to be associated with bruxism, clenching and grinding than with TMD
[23].
Malocclusions like skeletal anterior open bite, overjet greater than 6 to 7 mm, long
face, centric relation to centric occlusion slides greater than 4 mm, unilateral lingual cross
bite, 5 or more missing posterior teeth, Class II and III malocclusions are known to be
associated with TMD, however subjects with normal occlusion have lower odds for
symptoms and signs of TMD [10, 18, 19, 24-26].
8
Occlusion
Erosion, abrasion, and attrition are frequently combined; differentiation between
them is not always possible. However, the most visible sign of functional wear probably is
related to attrition if occlusal factors involved in causing dental wear. Malocclusion and
masticatory forces are indicated by some studies as primary etiologic factors for non carious
lesion development, although other authors did not find this correlation. Due to the
controversies in the literature and the high prevalence of malocclusions in children, therefore
it is necessary to help professionals to differentiate between physiologic and pathologic
processes to verify the pattern of tooth wear of various occlusal relationships. Different
tooth wear patterns found in subjects with normal occlusion and those with malocclusions.
Angle’s Class II malocclusion has been associated with increased wear in posterior teeth, In
contrast, class II division II malocclusion is associated with increased wear in the anterior
teeth, on the other hand the absence of teeth contacts may prevent tooth wear, and the
presence of an open bite or crossbite may decrease the risk of wear. Among children, class II
malocclusion and absence of open bite was associated with increased tooth wear as well as
younger age and male gender [21]. Tooth wear on the malocclusion subjects is a
consequence of a different interocclusal arrangement and should not be considered
pathologic [2, 29].
Diet
Tooth wear can be induced by erosion, attrition and abrasion. Interaction between
erosive and mechanical wear is considered to be important. In Australia, the prevalence of
erosion in the deciduous dentition was recently found to be as high as 68%. Several studies
9
indicate a relation between dental erosion and a high consumption of cola-type and other
acid containing soft drinks. In vitro, exposure of human enamel to citric acid solutions
results in a considerable reduction in enamel hardness [27]. The critical pH of enamel is 5.5
and therefore any drink or food with a lower pH may cause erosion. This dietary pattern had
been shown to contribute in tooth wear, especially dental erosion [31]. The erosive potential
of erosive agents depends on the chemical factors, e.g. pH, titratable acidity, mineral
content, clearance on tooth surface and on its calcium chelating properties. Biological
factors such as saliva, acquired pellicle, tooth structure, tooth position and its relation to the
soft tissue and tongue are related to the pathogenesis of erosive wear. Behavioral factors,
which include excessive consumption of acidic foods and beverages like citric acid,
phosphoric acid, ascorbic acid, malic acid, tartaric acid and carbonic acids found in fruits
and fruit juices, soft drinks both carbonated and still, some herbal teas, dry wines and
vinegar-containing foods [34] readymade packaged or canned foods and bottled drinks,
drinking habits like swishing or holding drinks in the mouth, food stuffs, medications and
extreme oral hygiene, can play a role in the etiology of erosive wear. A relation was found
by the researchers between patients diagnosed with dental erosion and the cumulative
consumption of citrus fruits more than twice daily, consumption of soft drinks daily, and
consumption of apple vinegar or sports drinks once a week or more. Another study by
Stafne and Lovestedt reported that consumption of lemon juice daily for therapeutic reasons
showed a marked degree of erosion after only three months of use, when compared to
subjects with less consumption of lemon juice who experienced less erosion after more than
a year of use. Eccles and Jenkins described 26 cases of erosion, which they associated with
the consumption of excessive quantities of fruit, fruit juices and other acidic beverages. An
increased risk has also been implicated in consumption of acidic beverage at bedtime
10
because of the nocturnal absence of salivary flow. Dental wear is also influenced by the
abrasiveness of the individual food, such as that seen in case reports involving patients who
are lacto vegetarians and constantly eat healthful but rough foods. Persons developed
obvious occlusal wear, with cupping of the exposed dentine which was similar to the
mediaeval population due to the raw-food diet, which was both fibrous and with a high acid
content. This suggested that an erosive diet makes the occlusal surfaces vulnerable to wear
even by weakly abrasive materials by softening them, such as raw vegetables, which would
not have an effect on sound dentine [36, 37].
Salivary flow rate
Saliva plays a major protective role against tooth wear. It functions as a lubricant, is
able to dilute and to buffer acidic drinks. Salivary proteins are also involved in building a
protective pellicle layer on the enamel surface; therefore, a reduction in salivary flow rate
may potentiate tooth wear by erosion and attrition. A clear relationship was found between
reduced salivary flow rate and the ability to clear dietary acids from the mouth [36]. In
addition, the bicarbonate level in saliva is positively correlated with salivary flow rate;
therefore, saliva produced at a low flow rate has a lower pH and a lower buffering capacity.
In addition, the salivary calcium concentration is lower in children than adults, which means
that children have a higher risk of demineralization [27]. Gambonand et al. and others
concluded that computer gaming may reduce the salivary flow rate as well. Autoimmune
diseases like Sjögren’s syndrome cause progressive destruction of the salivary glands, while
others lead to reversible effect on the saliva rate, as in hypertension, depression,
malnutrition, dehydration, diabetes, etc. Wide range of drugs as used worldwide, induce
11
salivary gland hypofunction. Table 1 shows the drug groups that have been most directly
linked to salivary hyposecretion [35]
Table 1: Drug groups which are related to salivary hyposecretion
Medicine group Examples
Anorectic Fenfluramine
Anxiolytics Lorazepam, diazepam
Anticonvulsants Gabapentin
Antidepressants - Tricyclic Amitriptyline, imipramine
Antidepressants - SSRI Sertraline, fluoxetine
Antiemetics Meclizine
Antihistaminics Loratadine
Antiparkinsonian Biperidene, selegiline
Antipsychotics Clozapine, chlorpromazine
Bronchodilators Ipratropium, albuterol
Decongestants Pseudoephedrine
Diuretics Spironolactone, furosemide
Muscle relaxants Baclofen
Narcotic analgesics Meperidine, morphine
Sedatives Flurazepam
Antihyperptensive Prazosin hydrocloride
Antiarthritic Piroxicam
Medical conditions
Cerebral palsy, Down syndrome, asthma, diabetes, cardiovascular diseases, GORD
are known to be directly and indirectly associated with dental attrition. Table 2 illustrates
patient at risk of developing attrition according to the analyses of the patients’ lifestyles in
southeast Queensland [32].
12
Table 2: Groups of patients at risk of developing excessive tooth wear.
Group 1 Healthy, active people whose sports or workplace dehydration reduces salivary protection of
the teeth against acids in sports or other soft drinks. Addiction to caffeine in cola beverages.
Group 2 Patients with anxiety states, depression, anorexia or bulimia nervosa on tranquillising or
antidepressant medications associated with xerostomia and reversible sialadenosis. The
medication results in loss of salivary protection against both acid soft drinks and intrinsic
acid vomiting.
Group 3 Patients with oesophagitis from GOR sometimes associated with alcoholism. Alcohol is a
dehydrating drug that has long-term effects on salivary glands. Erosion is produced both by
extrinsic acids in wines and spirits with mixes and by intrinsic acid from GOR.
Group 4 Asthma sufferers at risk either from the acidity of medications or from reduction in salivary
flow induced by medications. Asthmatics’ lifestyles and diet may include the risk factors of
Groups 1 and 2.
Group 5 Diabetics and patients with other cardiovascular diseases suffer reduced salivary protection
of the teeth as a result of their condition or from antihypertensive or diuretic medication.
Group 6 Patients with syndromes which may be genetic, epigenetic or iatrogenic which place them at
risk of dental erosion by affecting salivation.
Australian Dental Journal 2001;46:4. (32)
Tooth brush and tooth paste Oral Hygiene products
Oral hygiene practices alone have long been implicated in tooth wear. Tooth
brushing wear is time-dependent and appears to be influenced by many factors, including
the frequency, duration and force of brushing. Many oral care products such as toothpastes
and fluoride-rinsing solutions exhibit a low pH. This, on one hand, enhances the chemical
stability of some fluoride compounds and, on the other, favors the incorporation of fluoride
ions in the lattice of hydroxyapatite forming fluoridated hydroxyapatite. Many studies have
found that tooth brushing after exposure to citrus fruit juice accelerates teeth structure loss.
13
The clinical suggestion of this is that tooth brushing may do more harm than good by
accelerating tooth structure loss when performed immediately after ingestion of acidic foods
or beverages. Saliva reverses the transient demineralization of a tooth surface in early stages.
However, tooth brushing immediately after an acid challenge result in irreversible loss of
tooth structure by removing the partially demineralized tooth surface before saliva can repair
it. Individuals who are susceptible to dental erosion may not receive the benefit of enhanced
enamel remineralization through fluoride if their toothpaste also contains pyrophosphate.
Lussi and Jaeggi suggested that after topical application of acidic oral hygiene products with
a high fluoride content some mineral is dissolved from the enamel surface, thereby
increasing the local pH and leading to reprecipitation of fluoridated hydroxyapatite.
Moreover, the buffer capacity of saliva and the organic pellicle led to an additional
protective effect. It seems that highly concentrated slightly acidic fluoride applications are
able to increase abrasion resistance and decrease the development of erosions of enamel and
dentin. Wiegand et al. showed that toothbrush and abrasion of eroded dentin might be
influenced by the fluoride content, by the RDA value and particularly by the buffer capacity
of the applied dentifrice or gel [36-38].
Management
Clinicians play an important role in determining possible etiological factors in the
treatment of the parafunctional habits. Where it is the dentist’s responsibility to caution
parents and establish a multidisciplinary treatment [40] The available literature does not
provide sufficient support to treat bruxism in children. The most common treatment for
bruxism is patient/ parent education, rigid occlusal splint to protect the teeth and masticatory
system, which has not been proven effective in the primary dentition, stainless steel crowns,
14
psychological techniques, medications to relieve anxiety and improve sleeping, stress
reduction and change in lifestyle. Treatment is not always recommended because children
generally outgrow the condition. Children should be referred to a specialist when they have
upper airway obstruction or severe psychological problems. While children or adolescents
who are taking medications for conditions that may cause bruxism, other options should be
discussed with the patients’ primary care provider [41, 42].
In vitro softening of human molar enamel can be inhibited by the topical treatment
with NaF 12,000 ppm and concentrated fluoride varnish (22,600 ppm). Fluoride
mouthwashes are used in the treatment of dental erosion due to the fact that both saliva and
fluoride are important in the remineralization process whereby enamel erosion is repaired.
Some resistance to excessive tooth wear from acid erosion in adulthood, can be conferred by
prior exposure to fluoride in the first 12 years of life as it also does for resistance to
demineralization by dental caries. However, treatment with fluoride varnish (2.26%) for 24
h and high concentration F rinses (1.2%) for 48 h applied prior to acidic challenge have been
shown to offer in vitro protection against erosion [37, 38].
15
III AIMs
The aim of this study was to measure the prevalence and severity of dental attrition
and evaluate the difference between tooth attrition in private and government schools, boys
and girls, in mixed dentition period using Smith and Knight scale, and to measure the DFT
scores, molar and canine classifications, posterior cross bites, orthodontic appliance, space
maintainers, previous Trauma, tooth malformation, and Stainless steel crowns.
16
IV MATERIALS AND METHODS
IRB Approval and Sample Collection
As an ethical practice, an IRB approval been granted prior to carrying out the
research. After granting the permission to do so, representative schools were approached.
Further step was taken which is providing explanations to visited schools with the
importance and criticality of such a study. As a reward for volunteered families, tooth brush,
tooth paste, dental advices and free dental consultation were given for each child. A sample
size of four schools addressing approximately more than 400 students was selected. Details
are provided below.
Four schools selected (two private and two governmental), after which Informed
consents were given to children ranging from second grade to sixth grade. Selection of this
age is critical, the reason behind selection of this age frame is to target the mixed dentition
period. 1050 informed consents were distributed in the four schools with questionnaires. In
two weeks, 524 out of the 1050 were received back. The informed consents had details of
the research, the procedure of examination of the children who will be enrolled, together
with a questionnaire form to be filled by the parents. The parents were requested to sign the
informed consent and send it back to school (see appendix A-C).
The epidemiological surveys were conducted by two examiners under regular light in
an indoor setting, using a mirror, dental probe, gauze and torch light. The schoolchildren
were given one-to-one interaction by the examiners were attrition score data collected with
accordance to Smith and Knight Scale, (Table 3 and Fig. 1). In addition to that, other data
17
were taken in consideration such as the molar and primary canine relationship, complete
examination of both jaws, teeth malformation (hypomineralization, hypocalcification,
amelognesis imperfecta, dentinogenesis imperfect), space maintainers or orthodontic
appliances, and recording in case of present previous trauma (fractured teeth). Two dental
assistants assigned to record the findings on the examination form (see appendix D).
Table 3: Tooth Criteria classification with accordance to smith and knight scale
Score Tooth Criteria
0 No wear or negligible wear of enamel
1 Obvious wear of enamel, or wear through the enamel to the dentin in single spots
2 Wear of the dentin up to one-third of the crown height
3 Wear of the dentin more than one-third of the crown height
Figure 1: Demonstration of tooth criteria classification as specified in Table 3
18
Inclusion and Exclusion Criteria
In the following table (Table 4), further explanations were given for the selection of
participants and reasons of exclusion.
Table 4: Inclusion and Exclusion Criteria for participants
INCLUSION CRITERIA EXCLUSION CRITERIA
1. UAE nationals
2. Signed informed consent
3. Good general health as provided
through the medical history.
4. Mixed dentition (male and
females)
5. Availability during the screening.
6. Presence of the involved teeth
(primary canines, first and second
primary molars and permanent first
molars) in full occlusion.
1. Expatriates.
2. Complete permanent or complete primary dentition.
3. Diseases such as basal ganglia infarction, cerebral
palsy, Down syndrome, epilepsy, Leigh disease,
meningococcal septicemia, multiple system atrophy,
gastroesophageal reflux, Rett syndrome. , heart disease,
asthma or diabetes.
4. Badly decayed teeth, fractured teeth, large restorations
or crowns.
5. Congenital malformations like Ameliogenesis
imperfect, dentiongenesis inperfecta, enamel hypoplasia
and hypomineralization.
6. Fixed ortho appliance that prevent proper examination.
General information been asked in the questionnaire provided, questioinnair general
layout is provided below (Table 5):
19
Table 5: Questionnaire general layout
Par
ent’
s re
late
d i
nfo
rmat
ion
parents educational level:
1. Primary
2. Secondary
3. College and post graduate
Parents occupation:
1. Employed
2. Unemployed
Ch
ild
’s r
elat
ed i
nfo
rmat
ion
Total siblings number
order between siblings
Medical History status
Medications taken if any
Is your child overly emotional? Yes/No/Sometimes
Is your child hyperactive? Yes/No/Sometimes
Does your child have a normal sleep cycle? Yes/No/Sometimes
Does your child grind his/ her teeth at night? Yes/No/Sometimes
Does your child grind or clench his teeth in stressful or fearful situations? Yes/No/Sometimes
Does your child complain of pain in the jaw or headache early in the morning? Yes/No/Sometimes
How many times does your child brush his/ her teeth per day? 0 /1 /2 /3/more than 3
What type of tooth brush does your child use? Soft /Medium/Hard
What type of tooth paste does your child use?
Does your child suffer from any gastroesophegeal reflux problems? Yes/No
Did your child get any dental trauma or jaw fracture? Yes/No
Does your child suffer any jaw problem? Yes/No
Ch
ild
’s r
elat
ed i
nfo
rmat
ion
Does your child have any oral
habits such as:
a) Putting things in their
mouths
b) Biting on their finger nails
or other objects
c) Sucking their fingers
d) Sucking a pacifier
e) Other (please specify)?
Does your child consume carbonated drinks? Daily/1/2/3- weekly/1/2/3-monthly/1/2/3-No
Does your child consume fruit based drinks? Daily/1/2/3- weekly/1/2/3-monthly/1/2/3-No
Does your child eat citric fruits? Daily/1/2/3- weekly/1/2/3-monthly/1/2/3-No
All children who matched the criteria submitted the consent, and the questionnaire forms
added up to (371) child of a mixed dentition period between second grade and sixth grade
(Figure 2). While (153) were excluded from the study, from which 27 (7M-20F) were absent
in the day of examination, 27 (12M-15F) were on the permanent dentition, 27 (18M-9F)
were asthmatic, 2 (males) were diabetic (type 1 diabetes), 3 (2M-1F) were suffering seizures
attach, 1 male with congenital heart problem, 1 female with cemented orthodontic appliance,
4 due to missing data on the examination forms, and 61 (22M-39F) were expatriates. The
20
expatriates who participated were examined and appreciation letters were given to each
along with tooth brush and tooth paste as an appreciation to their support.
Figure 2: Sample size layout
Inter-examiner Calibration and Preparation for School Visit
Two examiners were trained regarding the attrition scores using clinical pictures.
Then they were calibrated on 10% of the sample number and the calibration values were
calculated by Kappa statistics. The calibration was done with the same disposable kits that
were planned for the school visit.
The disposable kits contained a mouth mirror, probe and tweezer. Examinations were
planned at school in a non dental set up, and thereby torches were used for lighting. All
personal protective equipment like gloves and masks were carried to school, along with
disposable bags for non medical and medical wastes.
371 subject
private schools
184 subject
94 boy
90 girl
Government schools
187 subjects
74 boy
113 girl
21
The children were examined in their respective schools on the day of examination
and the scores were filled by the recorders in the Patient Examination Forms. The
examinations at both the venues were conducted during the whole day before they leave
school. Each school needed two days for the examinations. Each child after examination was
given an appreciation letter for their parents demonstrating briefly on the child's oral status
and the necessity of dental treatment with free consultation at our dental clinic and all
children were briefly educated about the importance of oral hygiene
DFT scores
All participants had full dental examination, all carious, filled, crowned, fractured
teeth recorded and data were collected on the presence of any orthodontic appliances or
space maintainers.
22
V. DATA ANALYSIS
The data analysis consisted of Multi-linear regression analysis, ANOVA, Kppa and
Kindall’s Tau-b. Tooth coded 5, 7, 8, 9 and the teeth on the unilateral cross bite side were
excluded from the statistical analysis as they were with tooth malformation, not fully
erupted or not in full occlusion, had extensive caries or large restorations, and missed
respectively. The general agreement percentage and Kappa values were measured for intra-
examiner and inter-examiner, in the cases were the Kappa statistics cannot be computed
Kendall's tau-b statistics was measured.
The intra-examiner and inter-examiner agreement percentage ranged from excellent
to absolute agreement as bellow (Tables 6- 9):
Table 6: Intra-examiner calibration of examiner A
Kappa value
Asymp. Std.
Error Approx. T
Approx.
Sig. Agreement
attrition 0.895 0.021 29.475 <0.001 Excellent
Molar classification 0.899 0.069 8.326 <0.001 Excellent
Canine classification 1 0 7.357 <0.001 Absolute
Posterior crossbite 0.721 0.187 4.442 <0.001 Very good
upper arch findings 0.968 0.01 33.34 <0.001 Excellent
Lower arch findings Kendall's/ .985 0.007 73.489 <0.001 Excellent
Previous Trauma 1 0 4.359 <0.001 Absolute
Tooth Malformation 1 0 4.359 <0.001 Absolute
Cross Tabulation
Ortho appliance All agree
space maintainer All agree
23
Table 7: Intra-examiner calibration of examiner B
Kappa value Asymp. Std. Error Approx. T Approx. Sig. Agreement
attrition 0.731 0.033 21.683 <0.001 Very good
Molar classification Kendall's/ .936 0.06 5.026 <0.001 Excellent
Canine classification 0.886 0.078 7.21 <0.001 Excellent
upper arch findings Kendall's/ .972 0.008 70.712 <0.001 Excellent
Lower arch findings Kendall's/ .979 0.008 72.515 <0.001 Excellent
Tooth Malformation 1 0 4 <0.001 Absolute
Table 8: Inter-examiner calibration first examination by A followed by B
Kappa value Asymp. Std. Error Approx. T Approx. Sig. Agreement
attrition 0.753 0.046 16.13 <0.001 good
Molar classification 0.756 0.164 4.879 <0.001 good
Canine classification 0.743 0.13 4.686 <0.001 Very good
Posterior crossbite 0.642 0.326 2.995 0.003 Very good
upper arch findings 0.975 0.011 27.782 <0.001 Excellent
Lower arch findings 0.95 0.015 26.866 <0.001 Excellent
Cross Tabulation
Previous Trauma All agree
Ortho appliance All agree
Tooth
Malformation All agree
space maintainer All agree
Cross Tabulation
Previous Trauma All agree
Ortho appliance All agree
Posterior crossbite All agree
space maintainer All agree
24
Table 9: Inter-examiner calibration first examination by B followed by A
Kappa value Asymp. Std. Error Approx. T Approx. Sig. Agreement
attrition Kendall's/0.846 0.027 29.999 <0.001 Excellent
Molar classification 0.677 0.109 5.994 <0.001 Very good
Canine classification 0.668 0.103 6.865 <0.001 Very good
Posterior crossbite 1 0 6.164 <0.001 Absolute
upper arch findings 0.938 0.013 35.882 <0.001 Excellent
Lower arch findings 0.944 0.012 36.752 <0.001 Excellent
Cross Tabulation
Previous Trauma All agree
Ortho appliance All agree
Tooth Malformation All agree
space maintainer All agree
25
VI. RESULTS
A total of (4822) teeth were evaluated. Among these teeth, (1944) presented with no
dental wear, (1016) scored 1, (1100) scored 2 and (8) scored 3, (53) teeth were excluded due
to tooth malformations, (49) permanent molar were not fully erupted or not in full occlusion
and (652) were not included due to large caries lesions or restoration or SSCs.
Responses to the Questionnaire
Among the 371 children examined, 184 were from private schools (90 girls, 94 boys) and
187 were from the government schools (113 girls, 74 boys), totaling 203 girls and 168 were
boys.
Parents related information
Education
Among the 371 children father’s reported as 2 were not educated (0.5%), 33 had
their primary education (8.9%), 157 had secondary or high school certificate (42.3%), 177
had Bachelors or postgraduate studies (47.7%), and 2 didn’t answer (0.5%). Mother’s
education were reported as 14 not educated (3.8%), 56 had primary education (15.1%), 178
had secondary or high school certificates (48%), 119 had Bachelor or postgraduate studies
(32.1%), and 4 didn’t answer (1.1%). Marital status was reported as 2.7% divorced and
18.3% with no answer. Father’s and mother’s education in private versus government
schools is seen in the following charts (Figures 3 and 4).
26
Figure 3: Father’s educational level
Figure 4: Mother’s educational level
0 2.2
25
72.9
1.1
15.5
59.4
23
not educated primary secondary or high school
bachelor or postgraduate
Father's educational level
private government
0.5 3.8
42.9
52.7
0
7
26.2
52.9
11.8
2.1
not educated primary secondary or high school
bachelor or postgraduate
no answer
Mother's educational level
private government
27
Employment
In the employment category, 51 fathers reported as being unemployed (13.7%), 319
employed (86%), and one didn’t answer (0.3%). Mothers reported as 298 unemployed
(80.3%), 72 were employed (19.4%), and one didn’t answer (0.3%). In the entire sample, 3
fathers passed away (0.8%), and 2 mothers as well (0.5%).
Father’s and mother’s employment in private versus government schools in the following
(Figures 5 and 6).
Figure 5: Father’s professional level.
6
94
0
21.4
78
0.5
not employed employed no answer
Father's employement
private government
28
Figure 6: Mothers’ professional level
Childs related information
Of the 371 subjects, answers showed that children 40.2% were emotional, 60.4%
hyperactive, ubnormal sleep cycle 4.9%, grind at night 4%, grind under stressful situations
4.3%, suffered morning headache or jaw pain3.8% , gastro-esophageal reflux 3.2%, and
dental trauma or jaw fracture 6.2% are as below (Figure 7).
74.5
25.5
0
86.1
13.4
0.5
not employed employed no answer
Mother's employment
private government
29
Figure 7: children related variables
The results in private versus government schools as seen in figure 8.
Figure 8: Overall comparison between private and Governmental schools
Variables on children habits:
15.1% of the participating children were putting things in their mouth, 25.1% biting
on their finger nails or lip, 1.9% sucking their fingers, and children playing videos games as
0
20
40
60
80
100
120
No
Yes
Sometimes
No answer
0
20
40
60
80
100
120
%
Private schools government schools
private vs government
emotional
hyperactive
normal sleep cycle
grind at night
gring under stress
morning headach or jaw pain
gastroesophegeal reflux
dental trauma or jaw fracture
30
7.5% while those not playing, the following percentages record the time spent playing video
games 17.8% as daily, 23.5% as 3-5/week, 28% 1-2/week or weekends only, 4.9% reported
playing only on summer and winter vacations, and 18.3% with no answer. (Figures 9 and
10).
Figure 9: Comparison between Habits adapted by participants in both private and
governmental schools
Figure 10: Frequency of video games played
83.7
16.3
86.1
13.9
73.9
26.1
75.9
24.1
98.4
1.6
97.9
2.1
No Yes No Yes
Private Gover.
Habits
Putting things in the mouths Biting on the finger nails or lip
Sucking the fingers
5.4
16.3
25
32.6
3.8
16.8
9.6
19.3 21.9 23.5
5.9
19.8
playing video games
Priv. Gov.
31
Dietary habits
Dietary habits of the 371 child reported that consumption of carbonated drinks
ranged from once a month to 21 times a week, the fruit based drinks ranging from none to
56 times a week and eating citrus fruits ranging from none to 35 times a week. The figures
below illustrate the difference in these variables in private versus government schools.
(figure 11, 12 and 13)
Figure 11: Consumption of Carbonated drinks per week
0
5
10
15
20
25
Carbonated drinks/week
Priv. Govr.
32
Figure 12: Consumption of fruit based drinks per week
Figure 13: Consumption of fresh fruit cuts per week
Oral Hygiene Practices
Most of the children reported brushing twice a day (54.4%) while, 33.7% brushing
once a day, 5.9% brushing 3 times a day, 4% brushing more than 3 times a day, 1.6%
reported not brushing and 0.3% no answer. Tooth brush type reported the majority (54.4%)
0 5
10 15 20 25 30 35 40 45
Fruit based drinks/week
Priv. Govr.
0
5
10
15
20
25
30
Eating citrus fruits/week
Priv. Govr.
33
used a medium tooth brush, while 43.3% used a soft brush, 1.3% used hard brush, and 0.8%
didn’t answer. Toothpaste type reported 38% used children’s toothpaste, while 20.7% used
adult toothpaste, 30.7% didn’t specify, and 0.5% didn’t answer. These three variables are
listed in the figures below for the combined numbers of private and government schools.
(Figures 14-16).
Figure 14: Teeth brushing frequency on daily basis
Figure 15: Tooth brush type
1.1
29.9
64.1
4.3 0.5 0 2.1
37.4
44.9
7.5 7.5
0.5
0 1 2 3 4 no answer
Teeth brushing/day
Priv. Govr.
43.5
55.4
0.5 0.5
43.3
53.5
2.1 1.1
soft medium hard no answer
Toothbrush type
Priv. Govr.
34
Figure 16: Tooth paste type
Prevalence of attrition in private versus government schools
The statistical analysis showed that attrition is significantly higher in the government
than in private schools and there was no difference in the attrition rates between girls and
boys. (Figures 17-20).
41.8
20.1
37.5
0.5
34.2
41.2
24.1
0.5
kids adult not specified no answer
Toothpaste type
Priv. Govr.
35
Figure 17: attrition prevalence according to school category
Figure 18: attrition prevalence scores according to school category
0.45383
0.56026
Private school Government school
Attrition prevalence
Mean
36
Figure 19: attrition severity score according to school category
Figure 20: attrition prevalence according to gender
0.23568
0.28868
Private school Government school
Attrition severity
Mean
37
Significant variables
Attrition prevalence
The analysis for attrition prevalence and the variables demonstrated a statistically
significant relationship between attrition prevalence and type of school (P=<0.001), right
canine classification (P=.001), number of siblings (P=0.004), and sucking fingers (p=0.023).
The prevalence of attrition in the examined teeth showed that as canines had the highest
rates followed by the second primary molars, first primary molars and the permanent first
molars respectively (P=<0.001) (Figure 21).
Table 10: Demonstrative data for the relationship between prevalence and type of
school, for models (Regression) and (Residual)
ANOVAe
Model Sum of Squares df Mean Square F Sig.
4 Regression 1.209 4 .302 12.708 <0.001
Residual .785 33 .024
Total 1.994 37
d. Predictors: (Constant), school, Rcan, Number, Sucking the fingers
e. Dependent Variable: attrition Prevalence
Table 11: Dependent Variable: attrition Prevalence
38
Figure 21: attrition prevalence according to teeth
Attrition severity
The analysis for attrition severity and the variables demonstrated a statistically
significant relationship between attrition severity and type of school (P=0.002), right canine
classification (P=0.000), right molar classification (P= 0.019), number of siblings (P=0.007),
and sucking the finger (p=0.023).
Of the 2124 teeth which were scored by 1, 2, and 3, most scored by 2 (51.78%), followed by
score 1 (47.8%) and 3 (0.3%). The prevalence of attrition was higher on the canines
followed by the second primary molars, first primary molars and first permanent molars
respectively while the severity of attrition scores were found to be highest on the canines
followed by first primary molars, second primary molars, and first permanent molars
respectively. On the segments the results were as follow, attrition prevalence reported
highest on the upper canines, upper primary molars, lower primary molars, lower canines,
upper permanent molars and lower permanent molars respectively while the attrition
0
5
10
15
20
25
canine 1st primary molar
2nd primary molar
1st permanent molar
prevalence of attrition
Series1
39
severity reported with highest attrition scores with the upper canines followed by the lower
canines, lower primary molars, upper primary molars and least by the permanent molars. On
the comparison between upper and lower jaws the results showed that the upper jaw attrition
is higher when compared with the lower jaw (p<0.001) (Figures 22-26).
Figure 22: Attrition scores frequency
Figure 23: Upper dental arch
47.8 51.78
0.3 0
10
20
30
40
50
60
1 2 3
Attrition scores freguency
%
0
10
20
30
40
50
60
70
16 55 54 53 63 64 65 26
upper dental arch
1
2
3
40
Figure 24: Lower dental arch
Figure 25: Attrition prevalence according to segments
0
5
10
15
20
25
30
35
40
45
36 75 74 73 83 84 85 46
lower dental arch
1
2
3
41
Figure 26: Attrition severity according to segments
Table 12: Predictors: (Constant), Rcan, Rmol, school, Number
ANOVAe
Model Sum of Squares df Mean Square F Sig.
4 Regression .364 4 .091 11.427 .000d
Residual .262 33 .008
Total .626 37
e. Dependent Variable: attrition Severity
42
Table 13: Dependent Variable: attrition severity
Coefficientsa
Model
Unstandardized Coefficients
Standardized
Coefficients
t Sig. B Std. Error Beta
4 (Constant) .150 .061 2.452 .020
Rcan -.017 .004 -.462 -3.925 .000
Rmol .027 .011 .283 2.457 .019
school .123 .036 .454 3.424 .002
Number -.011 .004 -.380 -2.900 .007
Primary canine attrition severity and classifications
The linear regression analysis showed that there is a significant relationship between
the canine attrition severity and the classification on the same side, right canines were
statistically significant with the right canine classification (P=<0.001) and left canines were
also statistically significant with the left canine classification (P=<0.001).
Table 14: Mean, Median, and Standard deviation values of the attrition prevalence and
severity.
Statistics
attrition
Prevalence
attrition
Severity
age
N Valid 371 371 38
Missing 0 0 333
Mean .50747 .26240 9.21
Median .55600 .26700 9.10
Std. Deviation .226337 .135590 1.059
Minimum .000 .000 7
Maximum 1.000 .889 12
43
DFT%
The analysis for DFT% score and other variables have shown a statistically significant
relationship, DFT score and type of school (P=.000), tooth brushing/day (P=.000), and
Mothers educational level (P=0.009). The mean value of the DFT% is 30.1%. DFT score
was higher in the government than the private schools; on the other hand teeth brushing
proved that increasing its frequency decreases the DFT score, while mother’s educational
level found to have interestingly the lowest DFT in the not educated mothers and the highest
in the mothers with primary education and bachelor or postgraduated mothers had DFT
scores higher than the mothers with secondary or high school education. (Figures 27-29).
Figure 27: DFT% according to school category
27.7001433
32.4435936
Private school Government school
DFT%
Mean
44
Figure 28: DFT% according to brushing frequency
Figure 29: DFT% according to mother’s educational level
Table 15: DFT% significant variables
0
5
10
15
20
25
30
35
0 1 2 3 more than 3
Teeth brushing/day
DFT%
27.6939429
32.4658852
29.4768797 29.8507691
not educated primary secondary or highschool
bachelor or postgraduate
Mothers education and DFT %
DFT%
45
Table 16: Mean, median and standard deviation values of DFT%
Statistics
DFT%
N Valid 371
Missing 0
Mean 30.0910468
Median 30.4347000
Std. Deviation 14.43571498
Minimum .00000
Maximum 73.91300
Other variables
Attrition variables
All other variables were not statistically significant (Table 17). One variable showed a
trend towards, the hyperactive children (P=0.091) which may be due to the sample size
being so large. If the samples with highest attrition scores were compared to subjects with
no attrition, other significant relations may be shown.
46
Table 17: Attrition excluded variables
Excluded Variablese
Model
Beta In t Sig.
Partial
Correlation
Collinearity
Statistics
Tolerance
4 Left molar classification -.143d -.742 .463 -.130 .345
Left canine classification -.093d -.591 .559 -.104 .527
Right posterior cross bite -.035d -.277 .783 -.049 .833
Left posterior cross bite -.016d -.137 .892 -.024 .982
DFT% -.122d -.907 .371 -.158 .705
age .070d .517 .609 .091 .708
Father’s education -.147d -1.269 .213 -.219 .926
Mother’s education -.048d -.411 .684 -.072 .962
Father’s employment .054d .418 .679 .074 .767
Mother’s employment .041d .349 .729 .062 .943
Divorced parents .089d .762 .451 .134 .944
Order between siblings -.001d -.007 .994 -.001 .940
Medical condition .117d .995 .327 .173 .924
medication .036d .302 .765 .053 .923
emotional .181d 1.607 .118 .273 .956
hyperactive .194d 1.744 .091 .295 .967
normal sleep cycle .101d .865 .393 .151 .937
grind at night -.102d -.791 .435 -.139 .772
grind under stress .007d .050 .960 .009 .741
morning headache or jaw pain .185d 1.512 .140 .258 .816
teeth brushing/day -.155d -1.316 .197 -.227 .899
tooth brush type .015d .125 .902 .022 .945
tooth paste type -.066d -.562 .578 -.099 .940
Gastro-esophageal reflux .148d 1.064 .295 .185 .651
dental trauma or jaw fracture .154d 1.341 .189 .231 .937
jaw problem -.026d -.217 .830 -.038 .923
Putting things in the mouths .069d .597 .555 .105 .973
Biting on the finger nails or lip .000d .001 .999 .000 .728
Sucking the fingers .227d 1.612 .117 .274 .613
Videos gaming .037d .320 .751 .056 .974
carbonated drinks/week .055d .475 .638 .084 .955
fruit based drinks/week -.059d -.472 .640 -.083 .836
eat citric fruits/week -.005d -.041 .968 -.007 .844
a. Predictors in the Model: (Constant), Rcan
b. Predictors in the Model: (Constant), Rcan, Rmol
c. Predictors in the Model: (Constant), Rcan, Rmol, school
d. Predictors in the Model: (Constant), Rcan, Rmol, school, Number
e. Dependent Variable: attrtition Severity
DFT% variables
All other variables were excluded from the DFT% because they were not statistically
significant (Table 18).
47
Table 18: DFT% excluded variables
Excluded Variablesd
Model
Beta In t Sig.
Partial
Correlation
Collinearity
Statistics
Tolerance
3 Father’s education -.005c -.077 .939 -.004 .700
Father’s employment .027c .523 .602 .027 .974
Mother’s employment .037c .662 .508 .035 .831
divorced .055c 1.070 .285 .056 .962
Father died -.018c -.346 .729 -.018 .989
Mother died -.035c -.699 .485 -.037 .992
Number of siblings .019c .340 .734 .018 .785
Order between siblings -.014c -.274 .784 -.014 .925
tooth brush type .022c .434 .664 .023 .982
tooth paste type -.029c -.560 .576 -.029 .952
Videos gaming .061c 1.185 .237 .062 .963
carbonated drinks/week .053c 1.010 .313 .053 .938
fruit based drinks/week .008c .149 .882 .008 .906
eat citric fruits/week .024c .452 .652 .024 .920
c. Predictors in the Model: (Constant), school, teeth brushing/day, Mother
d. Dependent Variable: DMFT %
48
VII. DISCUSSION
As a successful approach in tooth wear management, it is highly crucial to identify
the etiological factors. In many cases, the diagnosis might be complex due to multiple
etiologic factors that may confuse the clinical appearance of tooth wear [44]. Early
prediction of tooth wear can easily aid individuals whom are at risk of developing wear.
“The prevalence of tooth wear has been reported in several studies that have used many
indexes for analysis "[45-47]. In such a study, besides using indices for examinations,
different teeth and surfaces have been examined and surprisingly, results appeared in various
ways, which as a result made it more complex to compare the results. In this paper, the
Smith and Knight scale for epidemiological surveys was used, which demonstrated fair
accuracy and validity. It is highly important to mention that I would recommend other
working groups to conduct studies in order to validate the diagnostic criteria and grading.
The differences in the prevalence data among many studies [46-48] may be partly
explained by the differences in diagnostic criteria and indexes used, as well as varying
socioeconomic, cultural and geographical factors which could influence the outcome of
prevalence data. In this paper it was proven that the attrition prevalence was higher in the
government than the private schools, which is similar to an outcome of a study conducted by
Duze et al [49].
With accordance to study performed by Peres et al. [50], Gender was not
significantly correlated with tooth wear, this result came in sync with most studies assessing
tooth wear in deciduous dentition which have not found any differences between different
genders such as [52-61] On the other hand, a remarkable higher prevalence of exposed
dentine was found in UK boys than in girls and more boys had buccal/labial and
49
lingual/palatal tooth surface erosion than girls [62, 63]. Van Rijkom et al. [64] suggested
that the one possible reason for the difference in prevalence of erosive tooth wear between
boys and girls could be the difference of bite force and Pigno et al found that males among
children and adults had an increased prevalence of tooth wear, probably reflecting the higher
bite force of males compared to females [65]. In his study, mechanical tooth wear
assessment carried out, and none of the individuals correlated with tooth wear. Bruxism,
which is a strong risk factor for occlusal tooth wear, failed to demonstrate a significant
correlation as well. This result is similar to those of previous studies [66, 68]. This is
possibly due to parents' negligence of the presence of this condition and underestimating it
[67]. Marbach et al. found that only 34.4% of the patients with self reported bruxing in their
study showed evidence of tooth wear; the authors noted that evidence of tooth wear does not
necessarily indicate bruxing of the teeth [69]. Detmar et al. found no relationship between
degree of tooth wear and the level of bruxism activity as measured by EMCs [70]. There
was no association found between tooth wear and the socioeconomic status of children
estimated by their parents' education and occupation. In previous studies, tooth wear in
deciduous dentition has been uncertainly correlated with socioeconomic class. Harding et al.
and Kazoulis et al. found higher tooth wear rates in families with low socioeconomic status
[52, 55], on the other hand, Luo et al. and Mangueira et al. found higher tooth wear rates in
families with high educational level and in children who attended private schools [54, 74].
Where in this paper, attrition is found to be higher in the government than the private
schools and no association found with parents educational level. The occurrence of erosive
tooth wear can be influenced by the socioeconomic status of a population due to different
eating and drinking habits. Another possible interpolation can be also correlated to hygiene
habit of these groups. Millward et al. carried out a study examining the prevalence of
50
erosion of 178 4-year-old children and concluded that there is more erosion in the higher
socioeconomic groups [59]. In China, A remarkably higher prevalence of erosion was found
in children whom consumed fruit drinks in their childhood, and whose parents had higher
educational level [54]. The reasons expected for the increased erosion in the higher social
class was possibly due to the Western style diet, such as consumption of fruit juices,
carbonated soft- and other lifestyle-drinks; while the children from a more moderate or
lower educational background were more likely restricted to traditional drinks. In contrast to
these findings, Harding et al. found a correlation between low socioeconomic status,
frequent consumption of fruit squash and carbonated drinks and the occurrence of dental
erosion [55]. In this paper, it was not assessed if the children from the low socioeconomic
background had more plaque, which would be a diffusion barrier for erosion.
Harding et al. found higher odds ratios of erosive tooth wear in the group of frequent
consumers of carbonated and fruit drinks after conducting a study which is carried out
covering 202 5-year-old Irish children [55]. In a case–control study covering 103 British
aged between 2–7-year olds, significant finding correlated the prevalence of erosive tooth
wear with the frequency of consumption of acidic beverages, the habits of swishing and
holding the fluid in the mouth. Murakami et al. in a sample of 967 Brazilian children with
ages varied between 3–4 years, found higher odds ratios of erosive tooth wear in the group
that consumed soft drinks twice or more per day [75]. Al Majed et al. In a study conducted
with a sample of 46 children aged between 5–6-year-old boys in Saudi Arabia with
pronounced tooth wear (involving dentine and pulp) on the palatal surfaces of maxillary
incisors, found a remarkable relation between consumption of carbonated drinks in bedtime
and the number of affected surfaces [71]. Millward et al. in a group of 101 children aged 4–
16 years, assessing both deciduous and permanent dentition, found significant association of
51
tooth wear severity (no/mild–moderate– severe) with the frequency of consuming
carbonated drinks, fruit drinks, and fruit-based drinks at bedtime [59]. Surprisingly, the
present study and other investigators have not found any relationship between erosive
dietary factors and tooth wear [48, 53, 57, 76]. The sample size was enough to reveal the
effect of dietary factors on tooth wear. Yet, a larger sample could have helped to reveal the
correlations with more unlikely exposures, such as acidic medicine, gastric acids, and habits
related to physical wear.
Most commonly dental erosion, non-carious-lesions, have been investigated by
Walker et al, [48, 79]. In primary dentition, erosive tooth wear was identified in dentine [48,
79] and the most affected teeth were the molars [79, 80], incisors [48] or canines [55]. In
permanent dentition, tooth erosion was more frequently found in enamel [51, 77-79] and the
teeth most affected by wear were the molars [80] and canines [77]. The present study
analyzed a non-specific tooth wear cases inclusive of any type of wear. The results
demonstrated that canines presented higher tooth wear frequency and severity than the other
groups of teeth. This in accordance with Tartsitsa et al. who found that the most frequently
affected teeth were the canines and tooth wear involving dentine was mainly observed in
canines [28]. The prevalence and severity of tooth wear in canines found to be associated
with type of canine classification, however, additional research is necessary to support the
correlation between malocclusion and tooth wear described in the scientific literature.
According to previous studies class II malocclusion and absence of posterior or anterior
open bite was associated with tooth wear in children, but not in adults [66, 81, 82]. Many
etiological factors emerge to influence tooth wear, and it was found that there was an
association between the different lesions evaluated and gender. A logical approach can be
taken, that could explain the anomaly, through further investigation considering the
52
difference in enamel formation between primary and permanent teeth combined with other
variables such as bite force. A decent predictor of increased risk of erosion and general
tooth wear in permanent dentition is dental erosion in primary dentition. According to
Harding et al. children identified with erosive tooth wear extending to dentine or pulp at age
5 were five times as likely to have tooth wear on the occlusal surfaces of the first permanent
molar teeth at age 12 [17], Ganss et al. using orthodontic study models reported a similar
finding. So precise preventive and therapeutic measures are necessary required to avoid
increasingly the clinical problems [83]. In the present study no association found between
teeth wear and the frequency of teeth brushing which conflicts with [17] who found that
children brushing twice a day or more had less tooth wear on their incisors that those
brushing less frequently. In the present paper no correlation found between caries experience
and severity of tooth wear this confirms the results of [38]. There was no association
between children oral habits (putting things in their mouth, biting on their finger nail or lip)
with attrition prevalence or severity except for sucking the finger which showed a significant
relationship with attrition prevalence (p=0.023), in the present paper the association between
these habits and bruxism wasn’t studied, while in a study conducted by Shinkai et al. no
relation was found between bruxism and oral habits [84]. Other studies found a relationship
between bruxism and oral habits. Cheifetz et al reported that children with thumb sucking
habits had a smaller chance of showing bruxism (p = 0.06) [43, 85].
A systematic review of previous literature reviews demonstrated a fairly strong
indication for an inverse relationship between socioeconomic status and the prevalence of
caries among children [86, 89-92] A study on 13 to 14 year olds concluded that dental caries
experience and oral hygiene status of children were strongly correlated to socioeconomic
status [87, 88]. Another study done in the UAE Mohammed Mustahsen [93] found an
53
inverse relationship between socioeconomic status & DMFT in children which is consistent
with the results in this paper where we found that DFT% in government school is higher
(Mean value 32.4%), in comparison with private school students (Mean value 27.7%)
although private tend to greatly use the kids tooth paste (42.8%) when compared to
government school children (43.2%). And the majority of government school children tend
to use the adult tooth paste (41.2%) when compared to private school children (20.1%)
which confirm the findings of Martins et al. that children with a high socioeconomic status
tend to use a children's toothpaste [94]. Most of the children (54.4%) reported brushing
twice a day. No statistically significant difference found in the DFT% between girls and
boys in the present paper which conflicts the results of Arbabzadeh Zavareh who found that
girls have higher level of DMFT index [95]. Brushing frequency as found here is statistically
significantly associated with the DFT% greater brushing frequency resulted in less DFT%
and this is consistent with Costa el al who concluded that children who brushed their teeth
twice a day had less caries [99] similar finding was recorded by Whelton et al, at age 15 in
the Irish national survey [98]. According to Baccush et al. children whose mothers had low
education exhibited a higher total DMFT score than those whose mothers had high
education [96] where the present study interestingly found that children whose mothers were
not educated had the lowest DFT% (27.7), and the greatest DFT% found in children whose
mothers had their primary education (32.4%) followed by the children whose mothers had
their bachelor or postgraduate study (29.8%), and then by the children whose mothers had
their secondary or high school study (29.47%). This could be due to the fact that doing
further studies after the high school would decreases the mother’s attention on the child oral
health, or due to the mother being employed. Fathers education and occupation where not
54
statistically related with the DFT% in the present paper while Mehdi et al. found significant
differences between the DMFT index with father’s education and occupation [97].
55
VIII. CONCLUSION
1. Attrition prevalence is significantly higher in the government (Mean value 0.56) than
in private schools (Mean value 0.45) while there was no difference in the attrition
prevalence between girls and boys.
2. Attrition severity is significantly higher in the government (Mean value 0.28) than in
private schools (Mean value 0.23)
3. A statistically significant relation found between attrition prevalence and type of
school (P=<0.001), right canine classification (P=.001), Number of siblings
(P=0.004), and sucking the finger (p=0.023).
4. A statistically significant relation found between attrition severity and type of school
(P=0.002), right canine classification (P=0.000), right molar classification (P=
0.019), number of siblings (P=0.007), and sucking the finger (p=0.023).
5. The severity of attrition scores found to be highest on the canines followed by
second primary molar, first primary molars, and first permanent molars respectively.
6. According to segments attrition severity reported with highest attrition scores with
the upper canines followed by the lower canines, lower primary molars, upper
primary molars and least by the permanent molars.
7. Attrition of the upper jaw was significantly higher than the lower jaw (p<0.001).
8. A significant relationship between the canine attrition severity and the classification
on the same side, right canines were statistically significant with the right canine
classification (P=<0.001) and left canines were also statistically significant with the
left canine classification (P=<0.001).
56
9. A significant relationship found between the canine attrition severity and canine
classification, Class I canine and cusp to cusp occlusion associated with higher
attrition scores on canines when compared to class II and III (p <0.001).
10. Primary canine class I on the right side of the jaw associated with higher attrition
prevalence and severity when compared to C.II and III (P= 0.000).
11. Molar Class I on the right side of the jaw associated with lower attrition scores when
compared to Class II and III (P= 0.019).
12. All other variables were not statistically significant with attrition but one variable
showed a trend in hyperactive children with (P=0.091).
13. The mean value of the DFT% is 30.1%. DFT score was higher in the government
(32.44%) than the private schools (27.7%) with no difference between boys and
girls.
14. A statistically significant relation found between, DFT score and type of school
(P=.000), teeth brushing/day (P=.000), and Mothers educational level (P=0.009).
57
LIMITATIONS AND FUTURE RRECOMMENDATIONS
1. The questionnaire variables filled by the parents in terms of accuracy the information
will be more accurate if collected by one to one interaction with the parents.
2. The variables of attrition like bruxism, dietary habits and Oral Hygiene habits might
show significant correlation if done as control versus sever attrition groups.
3. Additional research is necessary to support the correlation between malocclusion and
tooth wear.
58
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