We investigated the feasibility of estimating the living age of Japanese individuals and distinguishing sex on the basis of results from stable isotope analysis of stable carbon (13C) and nitrogen (15N) isotopes in radicular dentin. In this study, collagen fibers were extracted from the radicular dentin of mandibular second molars in Japanese individuals born between 1891 and 1964, and the carbon and nitrogen isotope ratios (δ13C and δ15N values, respectively) were calculated. The results showed that regression formulae for δ13C and δ15N values were highly reliable for estimating the living age of Japanese individuals, but no sex difference was evident. Use of radicular dentin thus has potential as a technique for estimating the living age of Japanese individuals, whose diet has changed greatly over the years.
