[Year:2018] [Month:May-August] [Volume:3] [Number:2] [Pages:9] [Pages No:41 - 49]
Introduction: The foramen magnum (FM) is a large opening in the base of the skull. The dimensions of FM are clinically important because many vital structure passing through it, viz., the lower end of medulla oblongata, the vertebral arteries, and spinal accessory nerves. It may endure compression such as in cases of FM herniation, FM meningiomas, and FM achondroplasia. The knowledge of FM diameter is needed to determine some malformations such as the Arnold–Chiari syndrome, which shows expansion of the transverse diameter.
Materials and methods: The present study was carried out on 75 dry human skulls of unknown age and sex belonging to Rajasthan population by the Department of Anatomy at Mahatma Gandhi Medical College and Hospital, Jaipur, Rajasthan. All the measurements were taken with the help of digital vernier calipers.
Results: The mean anteroposterior diameter was 35.11 ± 3.12 mm, the transverse diameter was 29.35 ± 3.48 mm, area was 813.94 ± 146.40 mm2, and the FM index was 1.208 ± 0.150. The FM shapes were determined as oval (22.67%), egg-shaped (12.00%), round (14.67%), tetragonal (14.67%), pentagonal (9.33%), hexagonal (16.00%), and irregular (10.67%).
Conclusion: This study will be useful for the anatomists, radiologists, neurosurgeons, and orthopedic surgeons.