Validity of Demirjian’s and Kohler’s Age Estimation Techniques in Indian Adult Population

Aim: To evaluate the accuracy of Demirjian’s (DMJ) and Köhler’s (KHL) radiographic staging methods in estimating chronological age relative to the legal threshold of 18 years in an Indian adult population and to determine the molars with most predictive ability for forensic age estimation. Materials and Methods: This retrospective radiographic study analyzed orthopantomograms of 133 Indian individuals (80 females, 53 males) aged 12–24 years. Developmental stages of first, second, and third molars were assessed using DMJ and KHL criteria. Linear regression analysis was applied to derive age estimation equations for individual teeth, stratified by gender. Pearson’s correlation and adjusted R² were used to evaluate model performance. The relationship between specific tooth development stages and the legal age threshold of 18 years was also examined. Results: The highest predictive accuracy for age estimation was observed with DMJ staging of tooth 38 (R² = 0.607, standard error of estimate [SEE] = 3.177) and KHL staging of tooth 18 (R² = 0.650, SEE = 3.144). Gender-based differences were noted: males demonstrated earlier third molar maturation, while females exhibited faster development of first and second molars. The cutoff age of 18 years was best represented between KHL stages 7 and 8 and DMJ stage G. Combined staging of teeth 28 and 38 improved prediction (R² = 0.626). Conclusion: DMJ and KHL methods demonstrated reliable accuracy in estimating the chronological age near the legal threshold of 18 years in the Indian population. Tooth 38 (DMJ) and tooth 18 (KHL) showed the highest predictive value and are recommended for forensic use. The study emphasizes the importance of population-specific dental regression models, which can enhance the accuracy and reliability of age estimation in legal and medico-legal contexts, particularly in culturally diverse populations.