The applicability of Willems' and Lee's dental age estimation methods for Japanese children and the comparison with the Korean population.

This study aimed to examine the applicability of Willems' and Lee's methods in a Japanese population and to find the differences in teeth development between Japanese and Korean children by comparing the accuracy of their estimated age using the two methods. The developmental status of the lower left permanent teeth in 1,475 orthopantomograms of Japanese children were evaluated based on Demirjian's criteria, and the ages were estimated using Willems' and Lee's methods. The errors in estimated ages were calculated and compared with equivalent Korean population data. The accuracy of both methods for estimating the age of the Japanese population was similar to that in the Korean population except for that of Lee's method used in Japanese males. The results showed that there might be differences in teeth development between the Japanese and Korean boys. To increase the accuracy of the dental age estimation, the method that is derived from their own population data should be applied in forensic practice.