Sex Determination and Clinical Importance of Foramen Magnum on Basis of Its Morphometrical Analysis in Adult Human Dry Skull in Tribal Region of Central India.

Background: The Foramen Magnum lies in an anteromedian position and leads into the posterior cranial fossa. Its dimensions can be used in the eld of forensic identication and anthropology for determination of the gender of the human skulls. There are certain diseases like Arnold chiari malformation (tonsillar herniation), Achondroplasia, its stenosis, meningioma and Atlanto-occipital fusion associated with it. So, we are proposing the present study on basis of its morphometry for sex determination and its clinical importance. The present study is planned To evaluate its morphometry by following parameters: a. Anteroposterior diameter(APD)/Length(L) b.Transverse Diameter(TD)/Width(W) c. Area of FM by Radinsky Formula(1/4×APD×TD×π) d.FM index(TD×100/APD) e. Shape of FM. To nd correlation between male and female FM by using above parameters. 50 dry adult human skulls of Materials and Method: unknown sex and vernier calliper. After classication, Male (29) and Female (21) skulls were taken with All the above stated parameters and unpaired t-test is applied statistically. Antero-posterior diameter 34.90±2.366 is l Result: arger in male as compared to females 32.43±2.481, mean transverse diameter is slightly larger in male than females i.e. 29.76±1.864 and 29.24±3.375 respectively, Area of Foramen magnum is 816.79±85.145 in males and 748.95±128.391 in females, where males show the higher value. The Foramen Magnum index is larger in Females 90.14±8.344 than in males 85.55±6.738.The results were found to be Statistically Signicant except for Transverse diameter. The dimensions of Foramen Conclusion: Magnum - Anteroposterior diameter, Transverse diameter and its Area are larger in male skull as compared to female skulls. The Foramen Magnum index is larger in Females than in Males. Its shape shows sexual dimorphism, Oval shape being more common in Males. These parameters are helpful for posterior and lateral approach to Cranio-verterbral junction by neurosurgeons and orthopedicians. Radiological evaluation is also important for surgical approach to prevent complications like Haemorrhage, Atlanto-occipital instability.