Osteometric Assessment of the Radius for Sex Estimation in a Western Rajasthan Population: A Study of Sexual Dimorphism and Classification Accuracy

Background: Sex estimation is an important component of forensic skeletal identification. Although the pelvis and skull are considered the most reliable skeletal elements, long bones such as the radius can provide useful information when these bones are unavailable or damaged. Population-specific osteometric standards are particularly important because skeletal dimensions vary between geographical and ethnic populations. Material and Methods: The present study was conducted on 50 adult right radii obtained from cadavers belonging to the Western Rajasthan population at the Department of Anatomy, Dr. S. N. Medical College and associated hospitals, Jodhpur. Twenty-five male and 25 female radii were examined. Bones with pathological changes, fractures, or non-union of the epiphysis were excluded. Four morphometric parameters were recorded in millimetres: maximum length, distal breadth, minimum mid-shaft diameter, and maximum mid-shaft diameter. The measurements were statistically compared between males and females, and sensitivity, specificity, and overall accuracy were assessed. Results: All four radial measurements were significantly greater in males than females (p<0.0001). Mean maximum radial length was 249.24±10.77 mm in males and 221.52±10.27 mm in females. Mean distal breadth was 33.02±2.93 mm in males and 27.06±2.43 mm in females. Minimum mid-shaft diameter measured 11.87±0.93 mm in males and 9.79±0.94 mm in females, whereas maximum mid-shaft diameter measured 15.53±1.26 mm and 13.10±0.97 mm, respectively. Maximum mid-shaft diameter demonstrated the highest overall accuracy (92%), followed by maximum radial length (90%), distal breadth (88%), and minimum mid-shaft diameter (88%). Conclusion: The present study demonstrates significant sexual dimorphism in the radius of the Western Rajasthan population. Maximum mid-shaft diameter showed the highest classification accuracy among the parameters studied. These measurements may provide useful supplementary information for sex estimation in forensic and medico-legal investigations, particularly when other diagnostic skeletal elements are unavailable.

Keywords: Radius; Osteometry; Sexual dimorphism; Sex estimation; Forensic anthropology; Western Rajasthan; Skeletal identification; Morphometry.