Comparative analysis of Chaillet and Demirjian’s 8-teeth method and Acharya’s population-specific formula for dental age estimation in the Gujarati population of Western India

The Demirjian age estimation method, based on the developmental stages of mandibular teeth, is one of the most widely used techniques in forensic dental age estimation. Over time, this method has been modified by various studies, resulting in population-specific regression models. In 2011, Acharya proposed a regression equation tailored to the Indian population, derived from the developmental scores of the original Demirjian method. The present study assessed the developmental stages of eight mandibular teeth using 406 orthopantomograms (OPGs) and applied both the Demirjian and Acharya formulae to estimate ages by comparing the estimated ages with the chronological age (CA). Both methods underestimated the CA. The mean absolute error (MAE) was 0.24 ± 2.10 years for Acharya’s formula and 3.18 ± 2.46 years for Demirjian’s formula. Using Acharya’s formula, the MAE was less than 2 years in individuals aged 9 to 20.99 years, whereas with the Demirjian formula, the MAE was less than 2 years only in the age group of 9 to 16.99 years. Acharya’s formula demonstrated the lowest MAE for females (0.19 ± 1.97 years). The study also found a higher overall classification accuracy for Acharya’s formula (78.07%) compared to Demirjian’s formula (45.56%) for classifying a person as above or below 18 years. The present study showed that Acharya’s formula is more accurate for age estimation in the Gujarati population. Key Points Acharya’s Indian formula outperformed Demirjian’s original formula in dental age estimation for the Gujarati population, especially in determining whether individuals are above or below 18 years of age. The study highlighted the need for population-specific adaptations to improve accuracy, particularly for older age groups with high variability in third molar development. Refining forensic odontology standards, incorporating biological markers, and using multiple methods are essential for improving accuracy in forensic age estimation and human identification.