Dental Age Assessment Using Demirjian’s Method On Urumqi Juveniles

Objective:To validate the applicability of Demirjian’s method for age estimation in children and teenagers of Xinjiang Uighur population and to modify it, then establish a mathematical model for the region. Methods:Digital panoramic radiographs of796children of Xinjiang were assessed in Demirjian’s method. There were385boys and411girls involved in this study with chronological age from3to16years. The dental maturity scores (DMS) and dental ages of all the subjects were calculated.Paired t-test was performed between the chronological age and the dental age determined by Demirjian’s method and compare the difference between the dental age and the chronological age. The method of curve-fitting was used to established the mathermatical model between the dental maturity score and the chronological age initially. Results:The Demirjian’s method utilizing French-Canadian standards presented significant difference between dental age and chronological age for the sample. The results of paired t-test between chronological age and predicted age showed that there was significant difference (P<0.01), the mean difference between the dental age and the chronological age is0.25years in boys and0.31years in girls. Demirjian’s dataset is not suitable for estimating the age of3～16years old Uighur children. The regression equations were established as follow as:y(male)-64.38+26.11×-0.95×2, y(female)=-64.384+22.02×-0.95x2. Conclusion:The standards of dental age described by Demirjian etal may not be suitable for the Uygurs’ chileren in Xinjiang. We should establish a new mathematical model between tooth maturity and chronological age.