Age estimation of fragmented human dental remains by secondary dentin virtual analysis.

Unlike bones, teeth are remarkably resilient and can withstand severe trauma, making age assessment based on the dentition essential for forensic analysis. Modern techniques for age estimation focus on pulp-chamber volume measurements using radiographs and computerized tomography (CT); however, these are applicable only for complete teeth (i.e., with intact crown and root). In the current study, we developed a new approach using high-resolution micro-computerized tomography (μCT) to visualize the secondary dentin (SD), an inner layer surrounding the pulp which accumulates with age, thus facilitating age estimation of fragmented and broken teeth.The growth pattern of the SD with age was analyzed for 77 lower premolars from two anthropological collections. A comparison of SD virtual segmentation and histological measurement was highly correlative (ICC = 0.95). SD was measured per volume (mm3) of a 1 mm thick slice directly below the cemento-enamel junction. Regression analysis using SD measurements increased the success rates of age estimation (82%) compared with the "gold-standard" pulp/dentin method (54%) in the range of ± 10 years. The accuracy of age estimation based on SD analysis was improved to a range of 7-8 years.The SD method thus allows age estimation with greater prediction rates and better accuracy based on only a small fragment of a tooth in a non-invasive manner. This novel methodology is easy to use, accessible, and bears implications in various fields such as forensic sciences and anthropological research.