Sex estimation through discriminant analysis of the scapula in a contemporary Northern Thai population

This study evaluates sexual dimorphism in the scapula and develops population- specific discriminant functions for sex estimation in a Northern Thai population. Measurements of four scapular dimensions – maximum length, maximum breadth, glenoid cavity length, and glenoid cavity breadth – were taken from the left and right scapulae of 252 northern Thai individuals using a digital caliper. Discriminant functions using maximum length and maximum breadth were developed and tested for their accuracy in sex estimation. The cross-validation accuracy of these functions ranged from 81.67% to 86.67%, while functions using glenoid cavity dimensions ranged from 80.00% to 83.33%. Among the univariate functions, maximum length and glenoid cavity breadth provided the highest accuracies for sex estimation (86.67% and 83.33%, respectively), indicating that these dimensions are more sexually dimorphic and effective than the others measured. These findings contribute valuable morphometric data to physical anthropology and suggest that a multivariate discriminant function incorporating maximum length and glenoid cavity breadth could further enhance classification accuracy across diverse populations. This research highlights the importance of accounting for regional anatomical variations in forensic and anthropological applications.