Morphological and Morphometric Study of Foramen Spinosum in Dry Human Skulls: A Cross-sectional Study from South Bengal, India

Introduction: The Foramen Spinosum (FS), located posterolateral to the foramen ovale in the middle cranial fossa, provides passage to the middle meningeal vessels and the nervous spinosus. It is a critical landmark both surgically and radiologically. Abnormal morphology and a lack of proper anatomical knowledge of this foramen may interfere with various surgeries performed in cases of middle cranial fossa fractures, tumours and epidural haematomas. Aim: To study the various morphological variations and morphometric measurements of FS in dry human skulls from the South Bengal, India population. Materials and Methods: The present Institution-based cross- sectional morphometric study was conducted on 100 dry human skulls of unknown age, collected from the Department of Anatomy, IPGMER, Kolkata, West Bengal, India, from June 2024 to September 2024. The various shapes of the FS, along with its length, width and distance from the spine of the sphenoid, were measured using vernier callipers. The mean, standard deviation, and relevant p-values of these parameters were calculated using Statistical Package for Social Sciences (SPSS) software version 16.0. Results: Out of 100 dry skulls, 49 were of males and 51 were of females. The round-shaped FS was the most prevalent variety, found in 79 (79%) of the right-sides and 82 (82%) of the left-sides in both sexes bilaterally. Other shapes included almond (3% in both right and left), pear (4% on the right and 2% on the left), pinhole (2% on the right only), and oval (12% on the right and 11% on the left). Accessory FS was found in 2% of cases among females. The mean±Standard Deviation (SD) length was 2.84±0.87 mm for the right-side and 2.64±0.80 mm for the left-side; for width, they were 2.22±0.59 mm for the right-side and 2.25±0.62 mm for the left- side; and for the mean±SD distance between FS and the spine of the sphenoid, they were 4.38±2.11 mm on the right and 4.20±2.01 mm on the left. A significant statistical difference was observed in the male and female parameters on the right-side. Conclusion: A thorough understanding of the morphology and morphometry of the FS will be beneficial for neurovascular surgeries, ensuring maximum safety with minimal morbidity and mortality0