Sex estimation from the scapula in a contemporary Chilean population

- The scapula is useful for sex determination in the modern Chilean population.
- Discriminant function score equations were generated for use in sex determination.
- Accuracy of sex classification ranged from 80.7% to 86.0%.
- Other population functions had accuracy rates for Chileans from 76.3% to 85.1%.

The scapula is valuable for sex estimation in human skeletons. Muscles provide protection to the scapula making it difficult to fracture, therefore increasing the potential for undamaged scapulae at forensic scenes. The goal of this project is to evaluate the accuracy of discriminant functions, created using an indigenous Guatemalan and contemporary Mexican population, when applied to a contemporary Chilean sample for estimation of sex from the scapula. The length of the glenoid cavity (LGC) and breadth of the glenoid cavity (BGC) were measured. The sample included 114 individuals (58 males and 56 females) with age ranges from 17 to 85 years old. When the Guatemalan discriminant functions were applied to the Chilean sample they showed higher accuracy rates for sexing male scapulae (89.6% to 94.8%) than for sexing female scapulae (53.4% to 80.3%). When the Mexican discriminant functions were applied to the Chilean sample they showed higher accuracy rates for sexing female scapulae (82.1% to 96.4%) than for sexing male scapulae (56.9% to 89.6%). Size comparisons were made to a Guatemalan, Mexican, White American, and Greek population. Overall, in males and females of the Chilean population both left and right scapulae were larger than in the Guatemalan population but smaller than in the Mexican, White American, and Greek samples. Population-specific discriminant functions were created for the Chilean population with an overall sex classification accuracy rate of 80.7% to 86.0%.