DefinePK

Abstract

The foramen magnum is the biggest natural foramen of the neurocranium. It is located within occipital bone and connects the posterior cranial fossa with the vertebral canal (base of the skull). The structure is surrounded by various parts of occipital bone and secondary to their growth and development, the shape of the foramen may change during prenatal and postnatal period. Oval or oval-to-round forms of the foramen are the dominant ones for the contemporary human. However, numbers of anatomical variances have been already described, including circular, two-semicircular, heart-like, wide oval, bi-rounded oval, ventrally wide oval, bi-pointed oval and dorsally convergent oval forms. The structure is also directly or indirectly involved in numbers of pathological processes that may change its contour/shape. The linear diameters (length and width/breadth) as well as area of the foramen, especially with similar data of occipital condyles are helpful in sex determination.