Foramen magnum: it’s morphology and morphometry in dry human skull bones of northern india

The foramen magnum, an important landmark of the skull base, is also known as Foramen Primum. It is the largest foramen of the skull. The morphometry of the foramen magnum is clinically important because the vital structures that pass through it may suffer compression in cases of achondroplasia, herniation of the hindbrain through the foramen magnum, and atlantooccipital fusion. In neurosurgical practice, the transcondylar approach is commonly used to access the lesions which are ventral to the brainstem.
Aims and Objectives: This study was done to analyze the morphology and to do morphometry of the foramen magnum in dry human skulls. The objective of the present study was to see the shape of the foramen magnum and to evaluate its anteroposterior and transverse diameter with the calculation of the foramen magnum index and its area.
Materials and Methods: One hundred thirty-four dry, adult human skulls of unknown age and sex were observed in the Department of Anatomy K.G.M.U. Lucknow and Muzaffarnagar Medical College, Muzaffarnagar Uttar Pradesh. Anteroposterior and transverse diameters of the foramen magnum were measured with the help of a Vernier caliper. The area of the foramen magnum and its index were also calculated
Result: The mean anteroposterior and transverse diameter of the foramen magnum was 34.47 mm and 28.46mm respectively. The average foramen magnum index was 1.21 ± 0.1 and the average area of the foramen magnum was 770.79 mm2.
Conclusion: Detailed morphometric analysis will help in the planning of surgical intervention involving the skull base. This study will be useful for anatomists, neurosurgeons, radiologists, and orthopedic surgeons.