[Application of Demirjian and Chaillet method in age estimation of Uyghur and Han children and adolescents in Urumqi].

Purpose: To evaluate the applicability and accuracy of Demirjian and Chaillet method in estimating the actual age of Uygur and Han children and adolescents in Urumqi.

Methods: A total of 1144 orthopantomograms were included in the study, and the seven permanent teeth in the left jaw were divided into different stages according to two dental age estimation methods, and the dental age was converted to tooth age after checking the table and assigning points, and the dental age and its chronological age were compared with t test or rank sum test using SPSS 21.0 software package, and the accuracy of the two methods was evaluated by comparing the mean absolute error of the two methods.

Results: Demirjian method was overestimated by an average of 0.46 years (0.47 years for males and 0.43 years for women) in the Han population, 0.36 years for men and 0.26 years for women in Uyghur population, the difference was significant between Uyghur and Han boys (P＜0.05). Chaillet method yielded an average underestimate of 0.01 years (0.04 years for men and -0.08 years for women) in the Han population, and 0.08 years(0.02 years for men and -0.21 years for women) in the Uyghur population, there was no significant difference between Uyghur and Han boys and girls(P＞0.05).

Conclusions: When assessing the age of Uyghurhan children and adolescents in Urumqi, Chaillet method is more accurate than the Demirjian method. When applying dental age estimation method in different regions, it is necessary to evaluate the accuracy of the estimation method and revise it if necessary to improve the accuracy.