Age estimation in northern Chinese children by measurement of open apices in tooth roots

The aim of this study was to assess the accuracy of Cameriere’s methods on dental age estimation in the northern Chinese population. A sample of orthopantomographs of 785 healthy children (397 girls and 388 boys) aged between 5 and 15 years was collected. The seven left permanent mandibular teeth were evaluated with Cameriere’s method. The sample was split into a training set to develop a Chinese-specific prediction formula and a test set to validate this novel developed formula. Following the training dataset study, the variables gender (g), x₃ (canine teeth), x₄ (first premolar), x₇ (second molar), N₀, and the first-order interaction between s and N₀ contributed significantly to the fit, yielding the following linear regression formula: Age = 10.202 + 0.826 g − 4.068x₃ − 1.536x₄ − 1.959x₇ + 0.536 N₀ − 0.219 s ⋅ N₀, where g is a variable, 1 for boys and 0 for girls. The equation explained 91.2 % (R² = 0.912) of the total deviance. By analyzing the test dataset, the accuracy of the European formula and Chinese formula was determined by the difference between the estimated dental age (DA) and chronological age (CA). The European formula verified on the collected Chinese children underestimated chronological age with a mean difference of around −0.23 year, while the Chinese formula underestimated the chronological age with a mean difference of −0.04 year. Significant differences in mean differences in years (DA − CA) and absolute difference (AD) between the Chinese-specific prediction formula and Cameriere’s European formula were observed. In conclusion, a Chinese-specific prediction formula based on a large Chinese reference sample could ameliorate the age prediction accuracy in the age group of children.