The foramen magnum (FM) is a unique and complex anatomical opening in the base of the skull,which the posterior cranial fossa communicates with the vertebral canal. It is also related to a number of pathological conditions, including Chiari malformations, various tumours, and occipital dysplasias. The study aimed to compare and evaluate the foramen magnummorphology in dry skulls and CT scan images. Material and methods: The morphology of the foramen magnum was assessed in 118 adult non-pathological dry human skulls and 3D computer tomography images in 118 individuals (66 male, 52 female) aged 18–75 years. Result: the incidence of various shapes of the foramen magnum was observed the most common shape was oval (33.89%) in skulls, followed by round (15.25%), tetrahedral (13.55%), pentagonal (7.32%), hexagonal (16.94%) and irregular (12.71%). The mean anteroposterior 33.76 ±2.1mm & 28.09+ 1.9 mm transverse diameter of the foramen magnum. The minimum and maximum values for AP diameter were 31.78 & 39.13. Inthe CT scan study, the mean anteroposterior diameter of FM in the male 35.96± 3.7 and 33.85±3.5 in females. The transverse diameter in males 30.38±3.5 and 27.83±2.5 in females. The FMI was observed in males 85.48±9.1 and 83.26±9.0 in female. Discussion: Results provides baseline data for the anatomist and important information for neurosurgeons to approach the cranial base with maximum safety and minimum mortality and morbidity.
: Ishwar B Bagoji