Assessment of Tooth Coronal Index Measurements on CBCT-Reconstructed Panoramic Images for Adult Age Estimation

Objective: This study aimed to evaluate mandibular premolar (p) and molar (m) teeth using cone-beam computed tomography (CBCT)-derived panoramic reconstructions, with particular emphasis on premolars, which are often poorly visualized on conventional panoramic radiographs. By overcoming these imaging limitations, CBCT may allow more accurate assessment of pulp cavity morphology and improve the applicability of the Drusini method.Methods: This retrospective study evaluated CBCT images of 101 individuals (52 women, 49 men; mean age: 37.4 ± 14.3 years, range: 18–71 years). Intra-observer reliability was assessed using intraclass correlation coefficients (ICC). Sex differences were examined with independent samples t-tests. The tooth coronal index (TCI) of mandibular premolars and molars was measured using Drusini’s method. Associations between TCI and chronological age were analyzed using Pearson correlation and linear regression. Model accuracy was assessed using coefficient of determination (R²) and standard error of estimate (SEE).Results: Intra-observer reliability was good to excellent, with ICC values ranging from 0.895 to 0.929. No significant sex differences were observed for any index (p > .05). All four indices showed significant negative correlations with chronological age, with correlation coefficients ranging from Pearson correlation coefficient (r) = -0.354 to -0.411 (p < .001 for all). Simple linear regression models explained 12.0% to 16.9% of the variance in age. The combined first mandibular premolar- first mandibular molar model demonstrated the highest predictive performance (R² = 0.228, adjusted R² = 0.218; SEE = 12.7 years), representing a moderate improvement over single index model.Conclusion: Despite significant correlations, the Drusini TCI method does not provide sufficient accuracy for standalone forensic age estimation in the Turkish population and should be considered only as a complementary approach.