Sex Determination from Calcaneus in Thais

Abstract

     Skeleton plays a very important role in forensic anthropology where sex determination is the first step of individual identification. This study focused in sex determination by using calcaneus in Thais. Two hundred skeletons (male 115, female 85) adult calcanei from Anatomy Department of Medicine, Chiang Mai University were studied. The ages of individuals ranged obtained from 26-94 years with average of 67.6 years. Seven parameters of both left and right calcaneus in “millimeter” included maximum length (ML), minimum width (MW), body height (BH), load arm length (LAL), load arm width (LAW) dorsal articular facet length (DAL) and dorsal articular facet width (DAW) were measured. Descriptive statistics were determined for means and standard deviation. Student’s t-test was used to compare all average variables between male and female and it was significant population difference (p>0.05). Sex determination according to discriminant analysis (stepwise method) for two discriminants derived from left and right calcaneus could be calculated by the equation:

     YL = 0.069ML + 0.106BH + 0.174DAL + 0.402DAW – 22.005

     YR = 0.075ML + 0.097LAW + 0.144DAL + 0.434DAW – 22.044

     Sectioning point of two equations are -0.418 and -0.421 respectively. The result higher than sectioning point, was classified as male and lower the level were defined as females. Left calcaneus showed 90.5% (male 91.3%, female 89.4%) accuracy in sex determination and right calcaneus 91% (male 90.4%, female 91.8%).