Sex estimation from the carpal bones in a Thai population

Abstract

© 2019 Australian Academy of Forensic Sciences. Research on the upper limbs of Thai skeletons has shown a relatively high level of sexual dimorphism in this population. However the wrist has not been extensively studied for sex estimation in Thailand. Therefore, the purpose of this study was to assess the utility of carpal bones for sex estimation in a forensic context in Thailand. Fifteen (15) measurements were taken on seven carpals from 100 skeletons (50 males, 50 females) who died in the northern area of Thailand. Six of the seven carpals produced logistic regression equations with correct allocation accuracies of 84.0% or higher. The only exception was the triquetrum, which did not reach the 80% threshold. Three of the four equations with the highest estimated accuracies came from the trapezium–the highest reaching 92.0%. The trapezoid and capitate each produced one measurement with correct allocation accuracies of 87.8% or higher. The single measurement with the best combination of correct allocation accuracy (89.1%), measurement error (0.05%), and measurability (44/50 bones) on both sides is trapezium maximum length. Combining this dimension with maximum length of the 1st metacarpal facet on the right side produced an allocation accuracy of 91.8%, with accuracies above 90% for both sexes.