RESUMO
The sex determination of individual is greatly useful in Anatomy, Archeology & Forensic departments. The hip bone is most reliable bone to determine the sex of individual. A biometrical study of posterior border of 100 adult human hip bones has been done. With the use of osteometric board & triflanged stainless steel caliper, various parameters were measure. Various variables of posterior border of hip bone were calculated by using range, mean, S.D. & P value. In all parameter the arch PB (arch of posterior border), the total angle of greater sciatic notch & the posterior angle of greater sciatic notch gives statistically significant differences between the means related to sex. Above three parameters were highly significant to determine the sex by posterior border of hip bone. The mean value of the arch PB of male was high than female. The mean value of posterior angle of greater sciatic notch was 2.5 times higher in female. We had also measure demarking point (DP) for above three variables. The demarking point gives 99.75% accurate data which were measure by adding & subtracting 3xS.D.from the means. In present study the demarking point for arch PB was >143mm in male & <126mm in female, total angle of greater sciatic notch was <460 in male & >860 in female & posterior angle of greater sciatic notch <110 in male & >250 in female. In medicolegal cases where 100% accuracy is required, the use of demarking point is preferable. This study is useful for carrying out medico legal examination of bones, cephalopelvic proportions in obstetric cases, for academic studies in Anatomy & for anthropological examination of skeleton, radiological study of pelvis & for archaeological examination of skeleton.