Relationship between different types of malocclusion and sex and age in students in Isfahan

Epidemiological data on the prevalence of malocclusion is essential in assessing the resources required for orthodontic services. The aim of this study was to verify the prevalence of malocclusion, their individual traits and their association with age and gender of schoolchildren in Isfahan. In this cross-sectional/descriptive study, 6151 schoolchildren in Isfahan, aged 6‒17, underwent clinical examinations. The relationship between the first upper and lower molars according to the Angle's classification, overbite, overjet, open bite, crossbite, spacing and bimaxillary dental protrusion were examined. Chi-squared test and t-test were used to analyze data) α=0.05). A total of 911 (15%) students had normal occlusion. Cl I malocclusion was found in 3686 students (60%), with Cl II div I in 1236 (20%), Cl II div II in 47 (1%) and Cl III in 271 (4.4%) students. The prevalence rates of deep overbite, open bite and crossbite were 10.7%, 4.5% and 12%, respectively. There was no significant association between different types of malocclusion and gender but crossbite in females (anterior crossbite, p value = 0.002 and posterior crossbite, p value = 0.003) and deep overbite in males (p value < 0001) were more frequent. Cl II and Cl III malocclusion and dental crossbite increased with age (p value < 0.001) whereas deep overbite and overjet decreased (p value < 0.001). Deep overbite was more frequent in Cl II malocclusion and open bite was more frequent in Cl III malocclusion (p value < 0.001). Under the limitations of the present study, prevalence of malocclusion was high among schoolchildren in Isfahan. Therefore, greater care is required to prevent its incidence in this age group. Considering the relationship between malocclusions and age, proper timing should be considered.