Sex determination from foramen magnum parameters in Thai cadaveric donor

The foramen magnum (FM) occupies a well-protected position, making it particularly intriguing for forensic research. The necessity for methods to estimate sex from cranial fragments becomes evident when only a partial skull is available for identification. The objective of this study was to assess sex differences in anthropometric measurements, including the length of the foramen magnum (FML), width of the foramen magnum (FMW), foramen magnum area (FMA), and circumference, with the aim of developing a binary logistic regression model in Thai cadaveric donors. Sixty adult dry skulls underwent both intraclass and interclass correlation analyses. Subsequently, 240 adult dry skulls of known sex (120 males and 120 females) were meticulously measured and analyzed to determine the optimal threshold for sex determination. Morphometric analysis of the FM was carried out using vernier calipers, and the area of the FM was precisely calculated. The FML, FMW, FMA, and circumference were all found to be significantly larger in males than in females. Furthermore, FM circumference exhibited an AUC (Area Under the Curve) value of 0.908, signifying it as an excellent parameter for sex discrimination. Lastly, binary logistic regression was executed. Significant sex differences in FM circumference were consistently observed, demonstrating an accuracy of 81.62% when validated in 120 dry skulls.