Accuracy of Chaillet and Demirjian’s 8-teeth method in dental age estimation of Central Indian population using India specific regression formulae

Abstract Demirjian’s original method for forensic dental age estimation has undergone various modifications over the years, owing to the wide discrepancies in age estimates when applied on different population samples. Specific regression formulae were derived upon testing the revised method proposed by Chaillet and Demirjian on an Indian population. The objective of this study was to apply these formulae on a Central Indian sample of 400 healthy subjects, aged between 7-25 years and assess the ability of these formulae to predict age accurately. The study sample consisted of orthopantomograms of 400 subjects, categorized into four groups: Group A (7-16-year-old males), Group B (17-25-year-old males), Group C (7-16-year-old females) and Group D (17-25-year-old females). Based on the radiographic developmental stage of each tooth in the mandibular left quadrant, their respective maturity scores were allotted and a total maturity score for all the 8 teeth was determined for each subject. This value was then substituted in the India specific regression formulae, separately for males and females, to estimate the dental age. Difference between the chronological age and estimated age was then calculated. The mean absolute error for the entire sample was 0.5 years. The mean absolute error ranged between 0.7 ± 2.05 years for males and 0.4 ± 1.86 years for female subjects, implying greater accuracy in females. Further, 78.5 % of the sample showed negligible error of less than ±1 year. In case of male subjects aged between 7-16 years, least mean absolute error of 0.34 years was obtained. Higher error rates in Group B (17-25-year-old males) and Group D (17-25-year-old females) indicated reduced tendency for accurate age prediction in subjects beyond 16 years of age. The results derived in this study, showed improved accuracy of India specific regression formulae in predicting the dental age of the population of central India.