Radiographic assessment of third molar development in a Russian population to determine the age of majority.

OBJECTIVE: To test the applicability of "Gleiser and Hunt dental staging system modified by Kohler" (GHK) to assess third molar (3 M) development in a Russian population in order to determine the age of majority. DESIGN: The sample consisted of 918 panoramic radiographs from Russian females (n = 551) and males (n = 367) within the age interval between 8 and 23 years. On each radiograph, 3 M development was classified based on the GHK technique. Statistics tested the data for normality. Mean age and standard deviation were described for each 3 M position. Ordinal logistic regression tested the performance of the technique to classify individuals below or above the 18-year threshold. Receiver Operating Characteristic (ROC) curves were used. RESULTS: The mean ages and standard deviation (SD) for apex closure in females were 21,11 (SD = 1,47), 21,11 (SD = 1,43), 21,24 (SD = 1,39), and 21,29 (SD = 1,28) years for the teeth #18, 28, 38, and 48, respectively. Among males, the same teeth showed mean closure ages of 20,57 (SD = 1,69), 20,64 (SD = 1,76), 20,68 (SD = 1,68), and 20,81 (SD = 1,62) years, respectively. Area under the curve (AUC) reached 0.904 and 0.915 for classifying females and males below or above the 18-year threshold. CONCLUSION: The GHK technique was able to describe 3 M development in a Russian population. The statistic model was able to classify individuals below or above the 18-year threshold. However, the outcomes must be carefully interpreted, especially in borderline cases (17-19-year spectrum).