Human age estimation from tooth cementum and dentin.

BACKGROUND Age estimation is an important factor in the identification of an individual in forensic science. The hard tissues of the human dentition are able to resist decay and degradation, long after other tissues are lost. This resistance has made teeth useful indicators for age calculation. Recent research has indicated that Tooth Cementum Annulations (TCA) may be used more reliably than any other morphological or histological traits of the adult skeleton, for age estimation. AIMS The purpose of this study was to examine the correlation between age and the number of incremental lines in human cementum and to correlate age with thickness of secondary dentin. MATERIALS AND METHODS The study sample consisted of 100 teeth. Teeth which were extracted because of periodontal disease and orthodontic, and prosthetic reasons were used in the study. The exclusion criterion was teeth with carious lesions. The age of the individuals at the time of tooth extraction ranged from 25-60 years. Longitudinal ground sections of each tooth were prepared and examined. STATISTICAL ANALYSIS Correlation between estimated age, which was calculated by using cemental lines and thicknes s of secondary dentin and actual age, was found by using Pearson's correlation coefficient. Correlation of increase in thickness of secondary dentin in different age groups was analyzed by ANOVA test. RESULTS A strong positive correlation was found between the estimated age, which was calculated by using cemental lines and thickness of secondary dentin and actual age. Correlation of increase in thickness of secondary dentin in different age groups was found to be non significant. CONCLUSION Countable cemental annulations are present in human teeth. Quantification of cementum annuli is a moderately reliable means which is used for age estimation in humans. As the age advances, the thickness of the secondary dentin also increases; hence, the amount of secondary dentin can also be an indicator of age of an individual.