Odontometric sex assessment in Indians

Abstract

Sex determination of unidentified skeletal remains is important and various hard-tissue parameters have been evaluated towards this end. The dentition is considered as a useful adjunct in skeletal sex determination, particularly since teeth are resistant to postmortem destruction and fragmentation. Sex dimorphism in tooth size and the accuracy of odontometric sex prediction, is found to vary in different regions and researchers have advocated the need for population-specific data. No odontometric standards exist for Indians for use in forensic sex prediction. Therefore, this study examined sexual dimorphism in Indians using univariate and multivariate statistics. Mesiodistal (MD) and buccolingual (BL) measurements of all teeth, except third molars, were obtained from 105 Indians (53 females, 52 males). The mandibular first molar was found to be the most dimorphic tooth, followed by the canines and the BL dimension of maxillary first and second molars. While canines have, conventionally, shown the greatest degree of sexual dimorphism across populations, first molars have also been reported as the most or among the most sexually dimorphic teeth in some studies. Hence, apart from canines, the first molar would be the tooth most likely to exhibit the greatest univariate sexual dimorphism. In general, the mandibular teeth and BL dimensions showed greater tendency to be larger in males. However, nine tooth variables exhibited reverse dimorphism, i.e. female dimensions were larger than those of males. Overall, using univariate analysis, merely 37.5% of all tooth variables were statistically larger in males ( p < 0.05); the magnitude of sexual dimorphism in Indians is reduced when compared to other populations but similar to South Asian groups. Stepwise discriminant function analysis revealed moderate accuracy in sex prediction: the mandibular teeth were able to determine sex to higher levels (75.2%) compared to teeth of both jaws taken together (74.3%) or using only maxillary teeth (62.9%). Hence, for optimum odontometric sex prediction in Indians, recovery of the mandible alone suffices. Interestingly, a few teeth that showed reverse dimorphism entered the stepwise discriminant analysis, implying that larger female teeth can contribute to sex assessment and teeth being larger in males may not be a prerequisite.