Assessment of Malocclusion of Japanese Junior High School Pupils Aged 12-13 Years in Iwate Prefecture According to the Dental Aesthetic Index (DAI)

The purpose of this investigation is to grasp the actual condition of malocclusion in Japanese junior high school pupils using the Dental Aesthetic Index (DAI). A total of 218 junior high school pupils aged 12-13 years were examined according to DAI. About 40% of the subjects had incisal crowding. The percentage of subjects with incisal spacing was 24%, and 71% of them had diastema of 1 mm or more. The percentage of subjects with anterior irregularity on the upper and lower arch was 39% and 33%, respectively. The percentage of subjects with anterior maxillary overjet and mandibular protrusion of 1 mm or more was 85% and 6% respectively. Dislocation by more than a half-cusp in the proximal or distal relationship in the molars was observed in 26% of all subjects. Mean +/- SD of DAI score was 25.3 +/- 7.3.