Sex estimation of the foramen magnum using computed tomography data in Malaysian juveniles

This study assessed the potential of the foramen magnum (FM) in the Malaysian juvenile population to estimate sex using computed tomography (CT) data. A total of 200 (male = 100; female = 100) CT images of Malaysian individuals aged between 8 and 16 were retrieved. The maximum length (FML) and width (FMW), area (FMA 1 and FMA 2), and index (FMI) of the three-dimensional image of the FM were measured and analysed using Mimics software version 20 (Materialise N.V., Heverlee, Belgium). These metric data were then used to develop sex estimation models through discriminant function analysis (DFA) and binary logistic regression (BLR). The results showed that all measurements in males were significantly higher than in females (p < 0.001), demonstrating a high potential for accurate sex classification. Additionally, females exhibited a wider FM than males, as indicated by the FM index. Based on univariate DFA analysis, FML and FMA 2 were identified as reliable variables for sex estimation, achieving an accuracy of 68.5% with a low sex bias rate of 1.2%. The multivariate DFA yielded a higher accuracy of 70.5% compared to the univariate analysis. Similarly, univariate and multivariate BLR analyses demonstrated comparable accuracies of 68.5%. Overall, the DFA showed greater accuracy and lower sex bias across all cases, including original and validation samples. This study suggests that FM parameters can complement existing sex estimation methods and be integrated with other techniques to improve skeletal sex determination.