The foramen magnum is a fundamental component in the interaction of bony, ligamentous and muscular structures composing the craniovertebral junction. The objectives of the present study are to find out the shape and dimensions of foramen magnum both in skull bones and cranial CT scans. All the variables were evaluated by using discriminant function analysis. The study sample comprised of 200 skull bones (105 males and 95 females) and 200 CT scans (119 males and 81 females). The FMs were classified into 8 types based on shape. Commonest being oval and pentagonal was the least common type in...