Sex Determination In Anthropology

DISCUSSION

Sex determination is an intricate part of forensic medicine, forensic anthropology and medico legal cases. It is also one of the most difficult tasks as fragmentary crania are very common due to warfare, explosions, intentional attempt to obscure the identity of the victim (3) and thus requires great expertise. It has been reported that when the complete skeleton of the victim is recovered, sex can be determined with 100% accuracy. This percentage decreases to 98% when only the pelvis and crania are present for determining sex, 95% when only the pelvis or pelvis and long bone and 80-90%when only the long bones are presented to forensic experts for sex determination. (59). Predominantly there are two approaches for sex determination:

The replicability of metric approach has been reported to be high. It is also more easily subjected to statistical analysis thus facilitating comparison between samples. (70) In the recent times, statistical methods utilizing metric traits have gained popularity with most of the bones being subjected to linear discriminant classification. (71)

Craniometric features which are essentially a part of anthropometric characteristics, form an integral part of forensic medicine as they can help in identification of the deceased individual from a detached skull. (72) Skull is the most sexually dimorphic portion of the body following pelvis, but sex determination from the skull is not reliable until well after puberty. (59) As the craniofacial features are composed basically of hard tissue, they are relatively indestructible. (73)

Giles and Elliot (8) reported an accuracy of 82-89% in sex determination, by developing a discriminant function technique that utilized the measurements of crania in intact skull. They also stated that “next to the pelvis, skull is the most easily sexed portion of the skeleton”. But in cases when fragmentary skulls are recovered, it poses a great challenge for the forensic science

When these variables were substituted in the Discriminant equation derived from the variables it showed an overall accuracy of 94%. The results of Stepwise discriminant analysis excluded the length of right occipital condyle, width of left occipital condyle and maximum median intercondylar distance as independent variables of sex determination.

Thus, the metric parameters that emerged as significant independent variables of sex determination at the end of study were the length and width of foramen magnum, length of the left occipital condyle,width of the right occipital condyle, minimum intercondylar distance, maximum median interncondylar distance and the area of foramen magnum. By substituting the values of the above mentioned parameters the oveall accuracy obtained remained the same (94%) as obtained earlier. Hence these metric variables can be considered as the significant determinants of sex in the present