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.

Lateral cephalometric norms for adolescent Kuwaitis: soft tissue measurements.

OBJECTIVE: The purpose of this study was to establish lateral cephalometric soft tissue norms for adolescent Kuwaitis and to compare these norms to those of the common analysis systems. SUBJECTS AND METHODS: Digital lateral cephalograms were made of 82 Kuwaiti boys and 80 Kuwaiti girls, of mean age 13.27 +/- 0.42 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 smaller Z angle, a larger H angle, thicker soft tissue at point A and the pogonion, and an increase in most measurements for lip protrusion when compared to the norms of the common analysis systems. The ranges of the majority of facial and labial parameters were larger than those reported in the above-mentioned norms. Gender differences were limited to upper lip length. CONCLUSION: Our findings suggest that Kuwaiti norms for lip protrusion should be used when making the extraction decision in adolescent Kuwaiti orthodontic patients. The larger than previously documented variation of the majority of soft tissue parameters suggests a need for establishing different norms for different facial types.

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 >or=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.

Lateral cephalometric norms for adolescent Kuwaitis: hard 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.

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 > or = 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.

Incisor trauma in an adolescent Arab population: prevalence, severity, and occlusal risk factors.

INTRODUCTION: Incisor trauma is a significant clinical problem in children and adolescents. The purposes of this study were to report on the prevalence and severity of incisor trauma in a large population-based sample of adolescent Kuwaiti residents in the early permanent dentition, to determine the ages of and reasons for the injuries, and to test for any effects of sex, incisor occlusion, and lip coverage on the prevalence of incisor trauma. METHODS: Presence and type of traumatic injury were scored according to the National Institute of Dental Research index in a population-based sample of 795 girls and 788 boys with a mean age of 13.24 years (SD 0.42). RESULTS: Trauma prevalence was higher (P < .001) in boys (19.3%) than in girls (9.7%), and in the maxilla (13.6%) than in the mandible (1.5%). Most (77.3 %) of the affected subjects had only 1 injured tooth, and most (83.7%) of the traumatized teeth were maxillary central incisors. A total of 90.3% of the injuries were unrepaired enamel or enamel/dentin fractures. The major reasons for the injuries were falls and blows indoors (48.4%) or outdoors (41.6%). Nearly two-thirds (63.0%) of the traumas occurred at age 10 years or later. Mean overjet (OJ) was larger (3.9 v 3.0 mm, P < .01), and lip incompetence more frequent (12.7% v 7.3%, P < .01) among the subjects with injured maxillary incisors than among those without. Logistic regression showed that the odds of maxillary incisor trauma were 2.8 times higher in subjects with OJ between 6.5 and 9.0 mm, and 3.7 times higher in subjects with OJ > or = 9.5 mm than in subjects with OJ < or = 3.5 mm. CONCLUSIONS: Multiple logistic regression showed that the risk of maxillary incisor trauma was about 2 times higher in boys than in girls, and that the risk increased by 13% for every millimeter of increase in OJ. Lip competence was not included in the model. No associations were found between occlusion and mandibular incisor trauma.