Utility of the sternal synostosis for age-at-death estimation in a Mediterranean population

Age estimation is essential for the identification of skeletal remains in Forensic Anthropology. Numerous studies have been performed on diverse regions of the skeleton, including the synostosis of the sternal segments. In this sense, the fusion of the different sternal segments was assessed to analyze whether it had a correlation with age-at-death in a Mediterranean population. A total of 189 sternums which belonged to individuals between the ages of 20 and 98 from both sexes (56.6% males; 43.4% females), from the San José's Cemetery of Granada Contemporary Collection (Spain), were selected. Scores ranging from 1 to 3 were assigned in accordance with the degree of manubrio-sternal fusion and sterno-xyphoidal fusion. Cohen's kappa coefficient for intra- and inter-observer error was performed and then chi-square test was run to analyze any correlation between the stage of synostosis and the skeletal age. Only the sterno-xyphoidal fusion, which starts between 30 and 39 years old, provided a predictable result, as the manubrium and the sternal body usually remain without fusion. This study demonstrates a direct correlation between fusion of the xyphoid process and chronological age.