Significance of Sacral Index in Estimation of Sex in North Indian Population

Abstract

Introduction: For the assessment of sexual dimorphism of human skeleton, pelvis has been used with great accuracy by anthropologists and forensic experts. Sacrum, being an integral part of pelvis, has therefore gained importance. Among the various parameters of sacrum, sacral index is the most reliable one, calculated by the formula: Sacral index=max breadth x100/max length of sacrum. This study aimed to determine the significance of sacral index in estimation of sex in north Indian population. Materials and methods: For the present study, 35 dry human sacrum bones were obtained from the Department of Anatomy, KGMU, Lucknow, out of which 32, free of deformity, were used in study. The bones were first separated as male and female on the basis of their gross features. Maximum length and breadth of sacra were measured using digital sliding Vernier calliper and sacral index was calculated. Results: Mean sacral index was significantly higher in females (109.52) as compared to males (92.37). Sex determination done on the basis of gross features were comparable to that done by calculation of sacral index, except in sacrum no. 5,13,14,15 &16. Sacrum no. 5,13,14 &15 were more curved forwards (female feature) while their sacral indices were much lesser (male feature). Sacrum no. 16 had a uniform curvature (male feature) while its sacral index was>105 (female feature). Sacrum no. 16 also had only 3 dorsal and ventral foramina, which was a variation. Conclusions: Sacral index is a reliable criterion for sex determination, useful for anatomical, medicolegal and anthropological purposes.

Determination of Sex by Sacral Index in South Indian Population

“…The results were consistent with that of previous studies. [5][6][7][8][9][10][11][12][13][14][15][16][17] The sacral index has the authenticity of 95% with respect to determination of sex and there is existence of variations of sacral index values among different populations secondary to differences in sacral morphometric parameters. The sacral index values for male and female sacra derived from the present study were clearly in conformity with most studies as tabulated in Table 5 i.e., studies of Mishra SR 5 , Mazumdar S 7 , Janipati P 8 , Somesh MS 10 and Masih WF 12 .…”