Estimation of sex in a contemporary Saudi population based on sternal measurements using multidetector computed tomography

Sex estimation is an essential step for identifying unknown individuals and usually depends on the presence of highly dimorphic bones, such as the pelvis and skull. Nevertheless, the body integrity can be compromised in certain circumstances, and these bones might be absent; therefore, the ability to use other bones for sex estimation is crucial. The aims of this study were to collect baseline data for sternal dimensions in Saudi adults, assess the existence of sexual dimorphism in the sternum, and generate population-specific equations to estimate sex using sternal dimensions. During 2014-2015, 200 thoracic/thoraco-abdominal computed tomography (CT) images (100 men, 100 women) were anonymously collected from King Abdulaziz Medical City. Six measurements were obtained and two indices calculated after 3D reconstruction of the CT scans. Descriptive statistics were calculated, and sexual dimorphism was assessed using independent t-tests. Discriminant function equations were developed for these measurements. Except for the sternal index, men had significantly larger dimensions than women. Sexual dimorphism was highly significant (p < 0.001). The best predictor was the combination of the manubrium and sternal body lengths (89.5%). In the stepwise analysis, the best predictors were the manubrium length, sternal body length, manubrium width, and corpus width at the first sternebra, with a cross-validated accuracy of 90.5%. Cross-validated accuracy for all measurements ranged between 62.5% and 90.5%. The findings of the study may have important anatomical, anthropological, and forensic applications.