The use of ¹³C,¹⁴C and ¹⁸O of dental enamel to estimate the year of birth and geographic origin from Mexican individuals

Abstract In recent times, forensic science has increasingly relied on methods that use stable and radioactive isotope analysis to identify human remains. The use of 14 C-AMS dating of dental enamel and dentine of an individual allows the estimation of the year of birth, while that of stable isotopes of carbon and oxygen can provide information on their geographical origin. Isotopic analysis of a tissue complements existing identification techniques, enhancing the capacity to refine, exclude, and affirm investigative approaches directed towards individual identification. The primary aim of this exploratory study is to amalgamate diverse isotopic methodologies conducive to the prompt and accurate identification of a deceased individual. In this manuscript, we elucidate the application of a rapid processing technique for whole molars from individuals with documented ages, employed to ascertain age through 14 C-AMS dating. Furthermore, an investigation was undertaken to assess the capacity of carbon and oxygen-stable isotopes in distinguishing regional disparities. To achieve this, we conducted a comparative analysis of tooth samples sourced from individuals residing in three cities within the Mexican Republic: Mexico City in the central region, Oaxaca City in the southern region, and Tepic Nayarit on the western Pacific coast. The age of dental piece formation, as estimated through 14 C-AMS, exhibited a precise correlation with the actual age. By means of the stable isotope outcomes, the data disclosed substantial disparities in 13 C and 18 O abundances among teeth from individuals residing in the three cities.