A three-dimensional (3D) approach to estimating sex based on the subpubic angle of the contemporary Korean population

The utility of the subpubic angle (SPA) as a sex indicator has not been tested for the Korean population. Moreover, the inconsistency in the SPA measurement methods makes the SPA comparisons between populations impractical. This study aims to present the SPA of the contemporary Korean population and generate a statistical model to discriminate between the sexes. Additionally, this study presents a standardized method for the SPA measurement from a 3D pelvic model. This study used the CT images of 139 resolved forensic cases (70 males, 69 females) in South Korea. The SPA was measured using an open-source software, which exhibited a high concordance and reproducibility within- and between observers. The Korean SPA is highly sexually dimorphic with the mean female SPA (91.0 degrees) greater than the male (66.2 degrees). With the age effect controlled for, the sex of an individual explains 75.1% of the SPA variance. The logistic regression model yields an overall discrimination accuracy of 92.8%. This study is the first to record the Korean SPA using CT images and will contribute to sex estimation of the Korean victims in a forensic context. Also, the proposed SPA measurement method will allow for inter-population comparisons of the SPAs.