Dental age estimation by cementum incremental lines counting: A systematic review and meta-analysis

The estimation of dental age by cementum incremental lines (CIL) is a widely investigated method; however, its reliability remains uncertain. The aim of this article was to assess whether CIL are a reliable biological indicator for estimating dental age. A search was performed in Embase, LILACS, PubMed/MEDLINE, SciELO, Scopus and Web of Science databases using a combination of terms related to the topic. Two independent reviewers used inclusion and exclusion criteria so that relevant articles were selected and evaluated. For the risk of bias analysis, a checklist from The Joanna Briggs Institute was applied. For the meta-analysis, Pearson's Correlation Coefficient between chronological age and estimated age was considered as an effect measure. The heterogeneity of studies was assessed using the Cochran's Q statistical test (p < 0.05), and the publication bias using the asymmetry of the Funnel plot and Egger's linear regression test (p < 0.05). Most selected articles had low risk of bias. Although not all studies were included in the meta-analysis, it demonstrated the presence of high heterogeneity among them. Despite this, the synthesized result indicated that the age estimated by CIL count has a high correlation with chronological age. Furthermore, the graphical analysis suggested the absence of publication bias, which was confirmed by the Egger's linear regression test. Therefore, there is scientific evidence that CIL are reliable in estimating dental age, but the method requires a standardized protocol to be followed, as well as the rigorous choice of the root area to be analyzed.

Tooth Cementum Thickness as a Method of Age Estimation in the Forensic Context

Estimating age at death is a key element in the process of human identification of skeletal remains. The interest in dental cementum stems from its increase in thickness throughout life and, at the same time, from the fact it should not be affected by remodeling processes. Since the age assessment is particularly difficult in adults when using traditional anthropological methods on the skeleton, we tested a dental method based on maximum cementum thickness and developed new regression equations. We microscopically analyzed the histological sections of dental roots from a sample of 108 permanent teeth with known age and sex. Age at the time of dental extraction was in the range of 18–84 years. Our findings show that there were no differences in thickness between sexes, dental arch, and mono- and pluriradicular teeth. Separate regression equations were developed for individuals in the whole age range and individuals under 45 years. The equations were then tested on a hold-out sample from the same Mediterranean population demonstrating higher reliability for the equation developed for those under 45. Conversely, due to the increased error in age estimation in individuals over 45, this method should be used with caution in the forensic context when skeletal remains presumably belong to elderly individuals.