Curvature of the greater sciatic notch in sexing the human pelvis

Abstract

The maximum curvature of the greater sciatic notch and two standardized indices were calculated for use in the sexing of human hip bones. This was done by means of quadratic regression of the contour points of the greater sciatic notch. The new variables are not directly affected by the osteometric landmarks (e.g. ischial spine, tubercle of the piriformis, and posterior inferior iliac spine) which determine the greatest width of the notch. These landmarks are, however, known to be ill-defined on occasion, but nevertheless have been used to derive the conventional depth-to-width index and angles of the sciatic notch. The curvature parameter and its new indices were applied to the sciatic notch of 164 Japanese hip bones of known sex (104 males and 61 females). The accuracy of the new variables in the determination of sex was assessed and compared with that of the conventional indices and angles of the sciatic notch. The best discriminating variable was found to be the posterior angle with an accuracy of 91%. The new parameters of the present study that represent localized shape of the sharply curved edge of the notch diagnosed sex with an accuracy of 88%. In paleoanthropological or forensic cases, using the maximum curvature of the sciatic notch and its indices may be applicable to sexing the hip bones of specimens with postmortem damage.