Age estimation using annulations in root cementum of human teeth: A comparison between longitudinal and cross sections

BACKGROUND: Age estimation is an important factor in the identification of an individual in forensic science. Research indicates that cemental annulations may be used more reliably than other morphological or histological traits of human skeleton for age estimation. MATERIALS AND METHODS: Twenty-five teeth were sectioned longitudinally, and twenty-five teeth were cross-sectioned at the mid portion of the root. Sections were ground, mounted and viewed under a bright light microscope. The area selected for counting was photographed under ×10 objective, magnified 5 times; cemental lines were counted and added to the eruption age of that patient, to obtain the chronological age. The statistical software SAS 9.2, SPSS 15.0, Stata 10.1, MedCalc 9.0.1, Systat 12.0 and R environment ver.2.11.1 were used for the analysis of the data. RESULTS: The P value comparing actual age and calculated age using longitudinal sections is moderately significant and the P value comparing actual age and calculated age in the age group of <30 years is significant. INTERPRETATION AND CONCLUSION: The middle third of tooth root was most suitable to count annulations. The cross sections are easier to count but longitudinal sections give more appropriate results on age estimation. Though the procedure predicts under assessment of age in the younger age group and over assessment of age in the older age group, it provides a close estimate of the actual age of an individual. It can be correlated with other age estimation methods for better reliability.