Prevalence of malocclusion in high school students in Japan according to the Dental Aesthetic Index

Abstract – The Dental Aesthetic Index (DAI) was used to evaluate malocclusion in Japanese high school students ( n = 409, ages 15–18 yr). The purpose of this study was to obtain basic data concerning malocclusion in Japanese high school students. This study used a sample of students from randomly selected urban and rural high schools in Japan's Kyushu district. The DAI scores for urban and rural high school students, as well as the total DAI scores from these two areas were significantly higher than that of American high school students. These results showed that the number of students with an acceptable dental appearance among Japanese high school students is significantly lower than among American high school students. This indicates a higher need for orthodontic treatment among Japanese high school students.