The purpose of this study was to investigate the prevalence and genetic tendency of Class Ⅲ malocclusion among 400 primary school students. Cephalometric head films and impressions for models were taken to evaluate the malocclusion and the results w...
The purpose of this study was to investigate the prevalence and genetic tendency of Class Ⅲ malocclusion among 400 primary school students. Cephalometric head films and impressions for models were taken to evaluate the malocclusion and the results were statistically analyzed.
1. There was no significant differences between the sexes for the occurrence of Class Ⅲ malocclusion. The prevalence of Class Ⅲ malocclusion was a 5 % among the students.
2. Among the students with Class Ⅲ malocclusion, there was a 10% genetic tendency for mandibular prognathism in the parents and a 5% in the grandparents including three generations. The results suggest a 20% genetic relationship between Class Ⅲ malocclusion and genetic tendency.