Although the skull appears to be one large bone, it is really made of several bony plates which are connected to one another at their sutures. This configuration covers the brain to provide protection for this vital organ. To allow for the proper growth of the brain and skull early in life, the sutures of the infant's skull are not joined at birth. The sutures act as a type of expansion joint for the skull in that they allow bony expansion as the brain grows. These bones expand to compensate for the larger volume of the growing brain.
New bone is added at the sutures.
Eventually the sutures will stop growing and adjacent cranial bones fuse. If this fusion happens prematurely, skull growth is restricted and, as a result, the head will take on an abnormal shape. Normally, the only way to correct these changes are with a surgical procedure. The ideal time to perform these procedures is the first year of life. Later in life, problems can arise in the growth of the middle third of the face.