Prevalence and gender comparison of malocclusion among Japanese adolescents: A population-based study

BackgroundA lack of studies regarding the prevalence of malocclusion, including gender comparisons, has precluded an efficient dental health policy in Japan. We aimed to describe the prevalence and perform a gender comparison of malocclusion requiring orthodontic treatment in Japan.MethodsOn the basis of the index of orthodontic treatment need, occlusal characteristics of a population-based sample of adolescents (ages 12–15 years) were evaluated by orthodontists.ResultsA total of 821 adolescents participated in this study. The prevalence of malocclusion was 46.5%. Multivariate logistic regression indicated that girls were 1.56 times more likely than boys to develop malocclusion, particularly with anterior crossbite and upper and lower crowding.ConclusionsThis population-based study revealed that approximately half of the Japanese adolescents included in this study had malocclusion, which occurred primarily in girls. This study may provide reliable baseline data regarding the orthodontic treatment needs of the Japanese adolescent population.