THE STERNUM AS A SEX DISCRIMINATOR IN A CONTEMPORARY SPANISH POPULATION

E. D. Fernández, D. A. C. Monllor, M. F. C. Rodríguez, M. B. López, J. M. González

Abstract: The sternum is a bone that is useful in the morphological discrimination of sex, especially when other bones with greater discriminating capacity are not available, such as the pelvis and certain long bones.
Satisfactory results obtained in different investigations, as well as the need to have more specific population reference values, have led to a significant increase in studies and publications in this regard.
In the present study, we analyse the utility of the sternum as a sex discriminator in a sample of 202 sternums (117 men, 85 women), from corps exhumed in the last 50 years, corresponding to the contemporary Spanish population. All the metric variables (lengths of manubrium of sternum and body of sternum, total length, and width at the level of the first and third sternebrae) have been statistically classified using discriminant analysis and decision trees. The best results, in agreement with multiple works, are provided by the total sternal length. A measure of the total length, “the 141.5 rule” (the length of the male sternum exceeds 141.5 mm, whereas the length of the female sternum is equal or less) allows us to discriminate 86.1% of the sternums of the sample, with a sex bias of 5.7. Consequently, this bone can be useful in forensic studies of bone remains of unknown identity.
Keywords: sternum, sex estimation, decision tree, discriminant functions, forensic anthropology, forensic science, identification.