Suthat Duangchit; Kaemisa Srisen; Worrawit Boonthai; Nareelak Tangsrisakda; Sitthichai Iamsaard & Chanasorn Poodendaen

In forensic anthropology, the radius bone has been shown to determine the sex of human remains in a number of different populations. The dry mass and growth of long bones, including the radius, are associated with sex hormone levels; however, the use of bone weight to determine sex has not been sufficiently investigated. The aim of this study was to apply bone morphometric parameters, including maximum length of radius (MLR), circumference at the midshaft of radius (CMR), and weight of radius (WR), to 400 sample radii from a Northeastern Thai population. Univariate and multivariate discriminant functions of all parameters were systemically applied. Equations for calculating sex classification were also determined. Descriptive data analysis showed significant sexual dimorphism in all variables (p < 0.05). The canonical correlation was highest in CMR (0.772) and the ratio of weight to length (0.747). Multivariate discriminant function analysis showed that the measured indices of the right radius were slightly greater than those of the left radius. The parameters demonstrating the highest values of the standardized canonical discriminant function coefficients were CMR (Rt. = 0.496, Lt. 0.431) and WR (Rt. = 0.681, Lt. = 0.715). Moreover, the results of the multivariable (stepwise method) indicated that the best accuracy rates for using combinations of CMR and WR were 94 % (right side) and 92 % (left side). In conclusion, the weight of the radius (rather than the length) is an effective parameter in determining sex.

KEY WORDS: Radius; Sex determination; Discrimination analysis; Accuracy rate.

DUANGCHIT, S.; SRISEN, K.; BOONTHAI, W.; TANGSRISAKDA, N.; IAMSAARD, S. & POODENDAEN, C. Determining sex from thai radius: discriminant function analysis including the dry bone weight as an effective variant. Int. J. Morphol., 42(4):1132- 1137, 2024.