Faraj Behbehani

Apical Root Resorption Six and 12 Months After Initiation of Fixed Orthodontic Appliance Therapy

The low explained variance of identified risk factors for apical root resorption in orthodontic patients suggests effects of parameters related to individual predisposition. Our purpose was to explore this hypothesis. We evaluated standardized periapical radiographs of the maxillary incisors made before treatment (T1) as well as at about six and 12 months after bracket placement (T2 and T3) of 247 patients aged 10.1 to 57.1 years at T1. The radiographs were converted to digital images, and commercially available software was used to correct for differences in projection. The results showed that 20.2%, 7.7%, and 5.3% of the patients had > or =1 tooth with >2.0, 3.0, and 4.0 mm resorption at T3, respectively. Pearsons correlation revealed an association between resorption from T1 to T2 and from T2 to T3 (P < .01). The risk of > or =1 tooth with >1.0 mm resorption from T2 to T3 was 3.8 times higher (95% CI 2.4-6.0) in patients with > or =1 tooth with >1.0 mm from T1 to T2 than in those without. Also, resorption was more pronounced (P < .001) from T2 to T3 in patients with > or =1 tooth with >1.0 mm and >2.0 resorption from T1 to T2 than in those without. The explained variance of identified risk factors was <10%. Orthodontic patients with detectable root resorption during the first six months of active treatment are more likely to experience resorption in the following six-month period than those without.

Dental age assessment for Kuwaiti children using Demirjian's method

Background: Dental age can be estimated based on the level of tooth mineralization during the developmental process. Various methods of determining chronological and radiographical stages have been used for dental age estimation. Aim: To test the validity of the standards of dental maturation of Demirjian and Goldstein (Ann Hum Biol 3:411–421, 1976) when applied to Kuwaiti children. Subjects and methods: The sample was selected from healthy Kuwaiti children attending the routine and emergency dental clinics of the Faculty of Dentistry, Kuwait University. Good quality rotational pantomographs were obtained for 509 children (263 girls and 246 boys) between 3 and 14 years. Maturation of the seven permanent teeth on the left side of the mandible was determined according to the crown and root development stages described by Demirjian et al. (Hum Biol 45:211–227, 1973). Results: There were statistically significant differences in the mean of dental maturation between Kuwaiti and French–Canadian children (p<0.0001). Kuwaiti children were dentally delayed compared to the Canadian standards (mean dental maturation difference of 0.69 year, SD=1.25 years, CI=0.58–0.80). The mean delay in girls was 0.67 year (SD=1.30 years, CI=0.51–0.83) and in boys it was 0.71 year (SD=1.18 years, CI=0.56–0.86). Using a non-linear regression model, function formulae were developed for Kuwaiti girls and boys. Conclusion: The standards of dental maturation described by Demirjian and Goldstein (1976) may not be suitable for Kuwaiti children.

Prevalence and Severity of Malocclusion in Adolescent Kuwaitis

Objectives: Our aim was to evaluate prevalence and severity of malocclusion in an adolescent Kuwaiti population. Subjects and Methods: Using a stratified cluster sampling method and excluding non-Kuwaitis, subjects with mesial migration and/or loss of first molars, and subjects with orthodontic treatment experience without availability of initial study models, we examined 1,299 Kuwaitis (674 boys and 625 girls) of mean age 13.2 ± 0.4 years in a regular well lit classroom. We scored molar and canine relationship, overjet, overbite, anterior and posterior cross bite as well as spacing and irregularity of the incisors using gloves, mirrors, rulers, and spatulas. Results: Fourteen, 15, and 71% met the criteria for almost ideal, mild, and moderate to severe malocclusion, respectively. Of the 86% with malocclusion, occurrence of class 1, half step class 2, full step class 2, half step class 3, and full step class 3 was 57.8, 24.9, 6.3, 8.8, and 2.2% for the first molars, and 36.1, 50.0, 6.2, 5.4, and 2.3% for the canines, respectively. Incisor malalignment was the most prevalent malocclusion trait (73.2%). Overjet ≧9.5 mm occurred in less than 1.5%, open bite in less than 3.5%, deep bite with gingival contact in less than 2.0%, complete posterior cross bite in less than 1.5%, and complete anterior crossbite in less than 2.0%. Median diastema was present in about 2/3 of the cases with maxillary anterior spacing as opposed to only about 1/3 of those with mandibular spacing. Conclusion: Our findings suggest that more than 70% of young adolescent Kuwaitis have moderate to severe malocclusion, with incisor malalignment as the most prevalent malocclusion trait.

Lateral Cephalometric Norms for Adolescent Kuwaitis: Soft Tissue Measurements

Objective: The purpose of this study was to establish lateral cephalometric hard tissue norms for adolescent Kuwaitis and to compare them with published norms. Subjects and Methods: Digital lateral cephalograms were made of 162 Kuwaitis (82 boys and 80 girls of mean age 13.27 ± 0.42 years and 13.21 ± 0.43 years, respectively), with almost ideal occlusion. Anatomic landmarks were identified directly on the digital images. Linear and angular measurements were calculated electronically using the Dolphin version 9 software package. Results: The average subject in the sample had a steeper mandibular plane, a more convex profile with a tendency for reduced chin protrusion, and a more protrusive dentition than the norms of the common analysis systems. In addition, the ranges of the skeletal and dentoalveolar parameters were larger than those reported in the above-mentioned norms. Gender differences were limited to maxillary and mandibular length and lower anterior facial height. Conclusion: The present findings indicate that Kuwaiti norms for incisor inclination and protrusion should be used as a reference when making the extraction decision in Kuwaiti orthodontic patients, and that the variation in skeletal relationships among subjects with satisfactory occlusal compensations is larger than previously documented, suggesting a need for establishing different norms for different skeletal patterns.

Prediction of maxillary third molar impaction in adolescent orthodontic patients.

The purpose of this study was to identify risk factors for maxillary third molar impaction in adolescent orthodontic patients. Radiographs made before treatment (T1) and after treatment (T2) and at a minimum of 10 years postretention (T3) of 132 patients that allowed accurate diagnosis of impaction vs eruption of one or both maxillary third molars were evaluated. Although univariate logistic regression revealed that the decision to extract premolars reduced the risk of impaction by 76% (P < .01), this parameter was not included in the final prediction model at T1. Multiple logistic regression analyses revealed that third molar impaction could be predicted at T1 according to the size of the retromolar space and the amount of mesial molar movement that will occur during active appliance therapy, reducing the risk of impaction by 22% and 34% for every millimeter increase in distance, respectively (P < .01). At T2, multiple logistic regression revealed that the odds of impaction were more than 60 times higher (P < .01) if the third molar was angulated mesially as compared with less than 30 degrees distally relative to the occlusal plane and almost five times (P < .05) higher if the third molar was angulated more than 30 degrees distally as compared with less than 30 degrees distally. Similar analyses at T2 showed 29% reduced risk of impaction for every millimeter increase in retromolar space and 18% reduced risk for every degree increase in angle MP/SN (P < .01).

Residual Need for Early Orthodontic Treatment and Orthodontic Treatment Experience among 13- to 14-Year-Old School Children in Kuwait

Objective: Our purpose was to determine the residual need for early orthodontic treatment and the parameters associated with orthodontic treatment experience in 13- to 14-year-old school children in Kuwait. Subjects and Methods: A total of 788 boys and 795 girls, representing about 6.7% of the target population, were selected according to cluster sampling methods. Information on nationality, family income and orthodontic treatment experience was collected through subject and family interviews. The occlusal morphology was recorded in a well-lit classroom or from initial study models of subjects with orthodontic treatment experience. Results: Only 6.7% of the 225 subjects with early treatment need, defined as overjet ≧6.5 mm, and functional posterior and anterior crossbite on 1 or more teeth, had treatment experience. Residual need for early treatment was present in 13.4% of the subjects. Only 26.8% of the subjects with treatment experience met our criteria for early treatment need. The odds of treatment experience were higher in the subjects attending private schools (p < 0.05), in those from families with an income of KWD >2,000 (USD 6,600; p < 0.01) and in subjects meeting the criteria for early treatment need (p < 0.01). Conclusions: About 15% of each birth cohort of school children in Kuwait need early orthodontic treatment. Less than 10% of those with a need have treatment experience at 13–14 years of age, and about 75% of those with treatment experience at that age do not need early treatment. The predictors for treatment experience at 13–14 years of age are private-school attendance, a high family income and need for early treatment.

Prevalence of asymmetric molar and canine relationship

The purpose of this study was to investigate the prevalence and severity of occlusal asymmetries in the molar and canine regions in a large population-based sample of adolescent Kuwaitis. Using a stratified cluster sampling method, 1299 Kuwaiti adolescents (674 boys mean age 13.3 years and 625 girls mean age 13.2 years), representing approximately 6.7 per cent of that age stratum in the population, were examined clinically for sagittal molar and canine relationships, with a view to recording half and full-step asymmetries. In this sample, 1244 subjects were examined clinically, while for the remaining 55, pre-treatment study models were assessed. All subjects were in the early permanent dentition stage. Descriptive statistical analyses were used to determine the proportion of different molar and canine asymmetries. Antero-posterior asymmetries were found to be a distinctive and common feature of the dental arches, with half-step outweighing full-step asymmetries both in the anterior and posterior regions. The total prevalence of an asymmetric molar or canine relationship was 29.7 and 41.4 per cent, respectively, with more than 95 per cent falling in the mild category. Patient gender did not influence the prevalence or magnitude of asymmetry. The results showed a clinically significant prevalence of asymmetric molar and canine relationships, which were mainly in the category of half-step asymmetry. Class II half and full-step asymmetries were more prevalent than Class III asymmetries in the molar and canine regions.