Morphological variations of the anterior thoracic skeleton and their forensic significance: Radiographic findings in a Spanish autopsy sample

The anterior thoracic skeleton may exhibit a number of morphological variations or anomalies, including accessory ossicles, atypical fusion or nonfusion of bony segments, and accessory foramina. Awareness of these minor skeletal variants is important in forensic medicine given that they may be mistakenly identified as pathological or traumatic lesions. The identification of subtle morphological anomalies may also aid in the process of individualization by serving as points of similarity if their occurrence was recorded antemortem. This study assessed the prevalence of anatomical variants of the sternum and ribs in a modern population from Spain, since the frequency of these skeletal anomalies differs between population groups. The occurrence of sternal clefts and foramina, bifurcated ribs, fusion of the manubriosternal and sternoxiphoidal junctions, and type of xiphoid process end was evaluated on posterior-anterior digital radiographs. None of the morphological variations were associated with sex or age, with the exception of two traits related to the xiphoid process. The xiphoid process was absent more often in younger individuals, particularly specimens below the age of 30 years, whereas, complete fusion of the sternoxiphoidal junction was more often observed in individuals above 50 years of age. However, these morphological variants are highly variable in the study sample and thus they have limited utility in forensic age estimation in the Spanish population. Nonetheless, the presence of various morphological anomalies such as sternal foramina, bifid ribs, and triple-ended xiphoid processes may provide information useful for establishing a personal identification.