Jian Wang1, Miaochen Wang1, Shihui Shen1, Ying Guo2, Linfeng Fan3, Fang Ji4, Jiang Tao5. 1. Department of General Dentistry, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China. 2. Department of Orthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China. 3. Department of Oral Radiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China. 4. Department of Orthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China. Electronic address: smilefang98@hotmail.com. 5. Department of General Dentistry, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China. Electronic address: doctor_taojiang@126.com.
Abstract
OBJECTIVE: The study evaluated the validity of the nonlinear equations (Qingdao model) for dental age assessment in an eastern Chinese population. MATERIALS AND METHODS: We studied 1073 digital panoramic radiographs of children aged 11-16 years from a Chinese Han population. Dental ages (DAs) were calculated using the Demirjian and the new model methods. Statistical significance was set at p < 0.05. For each method, differences between the chronological age (CA) and dental age were analyzed by paired t-tests and mean absolute error (MAE). RESULTS: The discrepancies between CA and DA determined by Qingdao model were 0.18 and 0.30 years for males and females, respectively. While using Demirjian method, these differences were and 0.46 and 0.30. The Qingdao model's MAEs between DA and CA were 1.23 and 0.90 years in males and females, respectively. As for the Demirjian method, MAEs were 1.43 and 0.86 years in males and females. CONCLUSIONS: This study showed that the new nonlinear equations were more accurate than the traditional Demirjian method. Especially, the new nonlinear Qingdao model is more competitive in 11-14-year male groups and 15-16-year female groups. We recommend a combined Qingdao model and Demirjian method may reasonably reflect the CAs among children in the eastern Chinese population.
OBJECTIVE: The study evaluated the validity of the nonlinear equations (Qingdao model) for dental age assessment in an eastern Chinese population. MATERIALS AND METHODS: We studied 1073 digital panoramic radiographs of children aged 11-16 years from a Chinese Han population. Dental ages (DAs) were calculated using the Demirjian and the new model methods. Statistical significance was set at p < 0.05. For each method, differences between the chronological age (CA) and dental age were analyzed by paired t-tests and mean absolute error (MAE). RESULTS: The discrepancies between CA and DA determined by Qingdao model were 0.18 and 0.30 years for males and females, respectively. While using Demirjian method, these differences were and 0.46 and 0.30. The Qingdao model's MAEs between DA and CA were 1.23 and 0.90 years in males and females, respectively. As for the Demirjian method, MAEs were 1.43 and 0.86 years in males and females. CONCLUSIONS: This study showed that the new nonlinear equations were more accurate than the traditional Demirjian method. Especially, the new nonlinear Qingdao model is more competitive in 11-14-year male groups and 15-16-year female groups. We recommend a combined Qingdao model and Demirjian method may reasonably reflect the CAs among children in the eastern Chinese population.