Morphometric Study of the Foramen Magnum in Adult Human Skulls of Central India: A Cross-Sectional Osteological Analysis

Abstract

Background: The foramen magnum (FM) is a crucial anatomical structure at the base of the skull, transmitting vital neurovascular elements. Variations in its size and shape are relevant in neurosurgical access, forensic identification, and radiological assessment.

Objective: To analyze the morphometric dimensions and shape variations of the foramen magnum in adult human skulls of Central India and to assess any sexual dimorphism.

Methods: A cross-sectional osteological study was conducted on 120 adult human skulls (60 male, 60 female) of known sex obtained from medical colleges in Central India. Parameters including anteroposterior diameter, transverse diameter, and FM index were measured using digital calipers. Shapes were classified as oval, round, egg-shaped, tetragonal, and irregular. Data were analyzed using descriptive statistics and independent t-tests.

Results: The mean anteroposterior diameter was 34.8 ± 2.6 mm in males and 33.2 ± 2.1 mm in females (p = 0.001). The mean transverse diameter was 28.1 ± 1.9 mm in males and 26.8 ± 1.8 mm in females (p = 0.003). The most common shape was oval (40%), followed by round (28.3%). The FM index was significantly higher in males, indicating sexual dimorphism.

Conclusion: Morphometric variations of the foramen magnum, including sex differences, are important for surgical planning, anthropological studies, and forensic identification. The predominance of the oval shape in this population provides relevant baseline data for future studies.

Keywords: Foramen magnum, Skull base, Morphometry, Sex determination, Osteology, Central India