[Prevalence of malocclusion among 1022 Kazak junior school students: an epidemiological study]

This study provided baseline data for oral public health though epidemiological survey to investigate the prevalence of malocclusion and the relationship with caries in Kazak junior school students in Xinjiang Aletai district, China.

Using stratified and cluster random sampling, 1 022 Kazak junior school students in Aletai district were chosen. According to the standard of Angle's classification and individual normal occlusion, a full clinical examination was carried out. The results were statistically analyzed by SAS JMP 10.0.

Of all 1 022 subjects, the prevalence of malocclusion was 43.64%. Among them there were 215 males (43.97%) and 231 females (43.34%). The composition ratios of Class I, Class II and Class III malocclusion were 30.92%，3.42% and 9.30%, respectively. The malocclusion prevalence in urban was 44.56%, and 43.06% in rural areas. There was no significant difference between them. Among children with malocclusion, crowding of dentition was the majority, and the others in turn were abnormal space of anterior teeth, deep overjet, deep overbite, cross jet, and open bite. The prevalence of caries was 59.49%, and DMFT was 1.382. Students who had caries with malocclusion was 1.54 times more than those who did not have caries.

Compared with other studies, the prevalence of malocclusion in Xinjiang Aletai district is not high. The incidence of malocclusion is closely related to caries.