Comprehensive evaluation of the greater sciatic notch for sexual estimation through three-dimensional metric analysis using computed tomography based models

The greater sciatic notch is an effective indicator for sexual estimation, which is the initial process to identify unknown skeleton. Visual assessment is the mainstream of analysis methods; however, the subjectivity of researchers is also questioned. Metric method using three-dimensional models reconstructed from radiographic images can ensure reproducible and stable measurement of the greater sciatic notch. In this study, the greater sciatic notch was analyzed in various manners, including distances, angles, and dimensions, with the aid of an automatic measurement program and a landmark verification system. Among 28 items, 15 measurements showed more than 85% accuracy. Measurements related to the posterior part of the greater sciatic notch near the posterior inferior iliac spine particularly showed higher accuracy (93.1%). To test this observation, “arithmetic posterior angle of the greater sciatic notch”, a generalized form of partial angle of the greater sciatic notch, was designed. It showed more than 90% accuracy. When the results of the three-dimensional measurements were applied to classify dry bones, it proved to be valid in contemporary Korean population. The method and results of this study can be referenced in wider use of the greater sciatic notch analysis.