What is the average shape of the normal cranium of the skull?

The average shape of the normal cranium of the skull is classified as oval. This is primarily due to the way the skull is structured, providing a balance between the need to house and protect the brain while also accommodating for the facial structure. The oval shape allows for a slightly elongated form, which is necessary to provide a more aerodynamic contour.

In terms of proportions, the cranium is not perfectly round, as a round shape would not adequately account for the varying contours that exist due to the presence of the forehead, the occipital region, and the sides of the skull. The oval shape facilitates the attachment of muscles and minimizes the risk of injury while still allowing for adequate space for the brain's growth and development.

Additionally, maintaining an oval shape contributes to the overall functionality of the skull, including how the skull responds to external forces and its ability to support the organs of hearing and vision. Understanding the normal anatomical shape is crucial in fields such as medicine and anthropology, where variations from this shape can indicate differing health or genetic backgrounds.