Dental Age Assessment :the Application Of Demirjian And Willems Methods For Xinjiang Urumqi Uygur And Han Children Aged 7?15 Years Old

Objective: The aim of this study was to use Demirjian and Willems methods to evaluate the applicability in estimating dental age of children aged 7-15 in Urumqi Uyghur and Han population.Methods: This retrospective study were selected 796 panoramic radiographs include Han 410(195 males and 215 females)and Uyghur 386(184 males and 202 females),the mean Demirjian and Willems estimated ages were compared to the mean chronological age were compared with paired t-test.The method of nonlinear regression was used to established the logistic model between the dental age and the chronological age.Results: Dental age by Demirjian method showed an overestimate in Han children,Willems method evaluate Urumqi Han children dental age is more accurately.In Uyghur children,a statistically significant difference was found between chronological age and dental age of Demirjian method and Willems method[P<0.05].Y(male)=-3.346+1.567X-0.028X2,Y(female)=-4.255+1.696X-0.031X2.Conclusion: Willems method can be applied directly to Han children.Establish the Uyghur adolescent the logistic model between the dental age and chronological age,revised dental age equation can be applied derectly to the Uyghur males and females.