Biological sex and stature estimations from dry sternum: A population-specific study in Northeastern Thais

Background Biological sex determination and stature estimation are crucial components to establish the biological profiling for human identification. The population-specific standards are still needed to apply for accurate assessment. Sternum has been demonstrated to have high sexual dimorphism in many populations, but has not yet been adequately studied in Northeastern Thais to be applied in cases where traditional bones are not available or fragmented. This study, therefore, aimed to develop the standard measurements in Northeastern Thai sternum. Materials and Methods The study examined 390 dry sterna (200 males, 190 females) collected from identified Thai skeletons. The length of manubrium, manubrium width, three corpus stern widths, and sternal body length were measured using a digital Vernier caliper. Logistic regression analysis was used for biological sex determination and the linear regression was employed to estimate the stature. Results All sternal parameters showed significant sexual dimorphism. The optimized multivariate model for biological sex determination using four sternal parameters achieved approximately 83.6% classification accuracy. For stature estimation, the combined equation using three measurements revealed the strongest correlation (r= 0.588) with a Standard Error of Estimate (SEE) of 6.24 cm. Sex-specific equations showed the improved precision of male SEE = 5.871 cm and of female SEE = 5.798 cm, respectively. Conclusion This study provided the standards for biological sex determination and stature estimation from sternal measurements. Dry sternum can be useful for sex dimorphism and stature evaluation in forensic identification for Northeastern Thai population when the classical bones like complete pelvis, skull, or long bones are unavailable.