Although the skull appears to be one large bone, there are actually several major bones that are connected together. The major bones that compose the skull of a newborn include the following:
These bony plates cover the brain and are held together by fibrous material called sutures.
Some sutures extend to the forehead, while others extend to the sides and back of the skull. One suture in the middle of the skull extends from the front of the head to the back. The major sutures of the skull include the following:
Sutures allow the bones to move during the birth process. They act like an expansion joint, allowing the bone to enlarge evenly as the brain grows and the skull expands, resulting in a symmetrically shaped head. However, if any of the sutures close too early (fuse prematurely), there may be no growth in that area. This may force growth to occur in another area or direction, resulting in an abnormal head shape.
There are two fontanelles (the space between the bones of an infant's skull where the sutures intersect) that are covered by tough membranes. The fontanelles include: