Anatomical revisit of mastoid region with sexual dimorphic potential - A study in eastern Indian population

Sex determination from skeletal remains is vital. Considering regional variability, need for population specific data is often emphasized to identify sexually dimorphic potential of bony skull fragments. However, limited amount of data is available especially from Eastern Indian population. In this context, different metric assessment of mastoid region in human skull were considered based on discriminant function formula.

A total of 40 male and 35 female adult human skulls were studied. Traditional measurements of four linear parameters of mastoid region on both sides were taken according to standard anthropometric references. The potential of mastoid region dimension in sex estimation was evaluated with ROC analysis and discriminant function formula.

All linear mastoid parameters yielded significant difference (p<0.05) between males and female skulls. Canonical correlation (0.597) and Wilk’s lamda (0.644) also indicated overall model as significant. Most accurate discriminant function was observed with linear distance between right sided porion and mastoidale with highest canonical discrimination function coefficient (0.776). Average 81.3% of original cases were correctly classified by the model in terms of sex prediction accuracy.

The studied mastoid parameters exhibited sexual dimorphism. Therefore, awareness of sexually dimorphic characteristic from fragmentary bony skull with intact mastoid region is worth knowing to correctly classify the individual with highest predictability and development of regional population specific discriminant function formula.