A comparison between incremental lines of cementum and aspartic acid racemization in age estimation: histological and biochemical study

Abstract

Background Age estimation is a vital aspect of the identification of an individual in forensic science. Teeth are one of the toughest structures in the human body and generally survive postmortem destruction. So, they can therefore be used more reliably than any other morphological or histological trait of the adult skeleton for estimating age. Aim of the study The present work aimed to compare cementum incremental lines and aspartic acid racemization in age estimation among Egyptian subjects. Methods Sixty-four subjects were assigned to two groups: males and females (each with 32 cases) to determine the effect of sex as a possible factor that might affect age estimation. For each group, in all subjects, age was estimated using histologic examination of ground, unstained section teeth by light and polarized microscopes, in addition to estimating the rate of aspartic acid racemization in the collagen of dentin by using the HPLC method. Results There was a statistically significant correlation between each method of age estimation and chronological age. However, the strongest degree of correlation was observed for the racemization method, with a correlation coefficient of r = 0.99 (95% CI 0.98 to 0.99), followed by the light method, r = 0.94 (95% CI 0.90 to 0.96), and the polarized method, r = 0.93 (95% CI 0.88 to 0.95). Conclusions Both methods, cementum incremental lines and aspartic acid racemization, could help in age estimation, but aspartic acid racemization is more reliable and accurate.