Objective: To evaluate the differences in the measurements of the Foramen magnum (FM) in relation to sex in an Egyptian population using cone beam computed tomography (CBCT).
Material and Methods: One hundred and twenty retrospective CBCT scans of adult Egyptian individuals were included in this study (sixty males and sixty females). The maximum length (sagittal diameter) and the maximum width (transverse diameter) of the FM were measured on axial CBCT images, then the foramen magnum index (FMI) and foreman magnum area (using two different equations) were calculated. All the measurements were statistically analyzed.
Results: It was found that all the FM measurements performed in this study were higher in males than that in females with statistical significance difference, except for the FMI which was higher in males, but the difference didn't reach the statistical significance level. Moreover, discriminant function analysis showed that FM length and FM area are the best sex discriminant measurements with overall accuracy of 65% and 64% respectively.
Conclusion: FM measurements assessed on CBCT scans can be used as a reliable indicator of sexual dimorphism in the Egyptian population.