Introduction:The foramen magnum (FM), located at the cranial base, serves as a crucial anatomical passage connecting the brain to the spinal cord.It serves as a passage for critical structures such as the medulla oblongata, surrounding meninges, vertebral arteries, and the 11th cranial nerve (accessory nerve).This study aimed to assess sexual dimorphism in FM dimensions using 3D computed tomography (CT).Materials and methods: Computed tomography head scans were obtained from Santosh Medical Hospital, Ghaziabad, and Dr OP Gupta Imaging Centre, Meerut.Measurement of the anteroposterior (AP) and transverse diameter (TD) of the FM was done using 3D reconstructed images.The foramen magnum index (FMI) was computed using these values.Results: Statistically significant sex-based differences were observed in FM dimensions.The mean AP diameter was 35.12 mm in males and 32.17 mm in females.The mean TD was 28.55 mm in males and 26.60 mm in females (p < 0.000).The oval shape was most frequently observed, followed by tetragonal and egg-shaped configurations.Conclusion: Marked sexual dimorphism exists in FM measurements.These parameters have important implications for both neurosurgical planning and forensic identification, especially in cases involving fragmented or incomplete skulls.
Sharma et al. (2025) studied this question.