The skull's two parietal bones are separated by the sagittal suture. This demarcation is located on top of the head and extends down the middle from front to back. Several sutures are in the skull. These narrow openings give bones flexibility when a baby is born.
As a child's brain and skull grow, the sutures provide space for expansion. This allows for even growth, resulting in a normal-shaped head. If sutures close too early, head growth can be asymmetrical.
By the age of 35, the sagittal suture is typically completely fused. When a skull is examined for anthropological or forensic reasons, the appearance of the sagittal suture is sometimes used to help identify the age of an individual.