Craniofacial Surgery - Craniosynostosis

Craniosynostosis

The bones of the human skull are joined together by cranial sutures (see figure 1). The anterior fontanelle is where the metopic, saggital and coronal sutures meet. Normally the sutures gradually fuse within the first few years after birth. In infants where one or more of the sutures fuses too early the growth of the skull is restricted, resulting in compensation mechanisms which cause irregular growth patterns. Growth in the skull is perpendicular to the sutures. When a suture fuses too early, the growth perpendicular to that suture will be restricted, and the bone growth near the other sutures will be stimulated, causing an abnormal head shape. The expanding brain is the main stimulus for the rapid growth of the skull in the first years of life. Inhibited growth potential of the skull can restrict the volume, needed by the brain. In cases in which the compensation does not effectively provide enough space for the growing brain, craniosynostosis results in increased intracranial pressure.

Craniosynostosis is called simple when one suture is involved, and complex when two or more sutures are involved. It can occur as part of a syndrome or as an isolated defect (nonsyndromic).

There are several classifications of deformities of the human skull, we will discuss them in order of prevalence.