Sex Estimation from the Mastoid Process Among North Indians*

Abstract

Determination of sex from fragmentary crania is a critical problem in forensic anthropology. Osteometric analysis of mastoid can serve forensic anthropologists better in sex identification by virtue of the noticeable dimorphic characteristics. The present study aims to develop population-specific, sex-differentiating anthropometric standards for the mastoid process of North Indian skulls. Eight parameters of the mastoid region were measured on 138 adult crania (M/F 104:34, 22-65 years) and analyzed using SPSS 16.0. All parameters showed significant sexual dimorphism (p < 0.000). In stepwise analysis, asterion-mastoidale and mastoid breadth have provided an accuracy of 87%. Receiver operating characteristic curves were obtained for each variable to observe their overall performance in sex determination. Posterior end of incisura mastoidea-depression of suprameatal triangle was found to be the best variable with maximum area under curve and highest predictive accuracy (82.6%).

Evaluation of the mastoid triangle for determining sexual dimorphism: A Saudi population based study

“…In addition, the males-females differences were statistically significant for all the 3 sides of the mastoid triangle in the North Indian study [3] similar to the results of the present study. In stepwise discriminant function analysis, AM provided the highest accuracy of 87% in the North Indian study [3] well above the accuracy level for this function in the present study. However, Kemkes and Gobel found AM to be statistically insignificant in sex determination in the German population [2].…”

“…In general, the malesfemales differences were statistically significant for AMT. In the North Indian study [3], all the 3 sides of the mastoid triangle were larger in males than females similar to the findings of the present # AP: Linear distance measured from the asterion to the porion; AM: Linear distance measured from the asterion to the mastoidale; PM: Linear distance measured from the porion to the mastoidale; AMT: Area of the mastoid triangle. Table 3 Step-wise discriminant function analysis and canonical discriminant coefficients for the variables.…”

“…The results of these validation studies [2][3][4][5] on the mastoid triangle and sex determination have failed to replicate the excellent results previously reported by Paiva and Segre [1]. Hence, it is necessary to validate a method on the population of interest before its routine use in determination of sex in forensic cases.…”

“…Since the publication of this Brazilian study, researchers have attempted to evaluate the usefulness of the mastoid triangle in sex determination in few other populations including the German, Portuguese, North Indian, South Indian and Nigerian [2][3][4][5].…”

“…Kemkes and Gobel [2] analyzed the mastoid triangle in 97 German skulls and 100 Portuguese skulls to evaluate the validity of the method published by Paiva and Segre [1]. Identification of sex from the mastoid triangle was tested with measurements on 138 North Indian skulls by Saini et al [3]. One hundred and eighteen skulls were tested with measurements to determine if the mastoid triangle method was valuable in identifying sex in South Indians [4].…”