RESUMO
OBJECTIVE: To compare the accuracy of Demirjian's stages (DS) and Cameriere's third molar maturity index cut-off value (I3M<0.08) to estimate the age of majority on panoramic radiographs (OPTs) from the dental clinic of the Scientific University of the South (UCSUR), Lima, Peru. METHODS: An observational cross-sectional study was conducted on the sample of 208 digital panoramic radiographs of patients aged 14-22years examined during 2015 in UCSUR. The left lower third molars were analyzed using Adobe Photoshop® CS6. An effectiveness of specific DS and I3M<0.08 was evaluated by using accurate classification, sensitivity, specificity, positive (LR+) and negative (LR-) likelihood ratios and Bayes post-test probability (p). RESULTS: Only G and H stages were practical for classify adults and minors in the tested sample, while I3M<0.08 showed the best performance in both sexes. For I3M<0.08, the accurate classification, sensitivity and specificity were 0.96, 0.96, 0.96 and 0.90, 0.84 and 0.95 in males and females, respectively. Values of LR+, LR- and p were 24.96, 0.04, 0.97 and 15.68, 0.17, 0.95 in males and females, respectively. CONCLUSION: The specific cut-off value of third molar maturity index (I3M<0.08) showed to be more accurate in discriminating adults and minors in Peruvian sample when a test with high sensitivity and specificity is required.