Abnormal Skull Shape

The skull is formed by five bones, with gaps between the bones (sutures). These six gaps are important to allow the bones to move during the birth process. They also allow the brain and skull to increase in size as the baby grows. If one or more of these "sutures" grow together, then the rest of the skull has to grow in a different direction, causing the skull shape to be abnormal. This problem can only be corrected surgically by a team of pediatric neurosurgeon and pediatric/craniofacial plastic surgeon. Most surgeries are completed before one year of age; some are completed at three to four months of age. The two problems that need to be corrected include increasing the volume of the skull to prevent increased pressures on the brain within the skull (intracraniol presure), and improving the appearance of the skull and forehead. Below are a list of terms that may be used to describe the exact suture or sutures that are involved.

Plagiocephaly - literally means "crooked skull" and can be used to describe a deformational skull shape or synostosis of the unicoronal suture (left or right). It is important to differentiate between the two causes. The asymmetry is usually on one side of the head and may involve the bones around the eye. Occasionally the posterior suture (lamboid suture) will fuse and cause a plagiocephaly.

Brachycephaly - usually refers to bicoronal synostosis (both coronal sutures involved) and causes the forehead region to be wide and high. The eyes may appear wide apart.

Trigonocephaly - refers to fusion of the metopic suture causing a triangular shaped forehead. The eyes may be close together. Some babies will have a ridge over the midline suture but a mild deformity of the forehead.

Patient with Metopic Synostosis and trigonocephaly		A: Preop B: 2 years after      frontal orbital      advancement
	A                           B

Scaphocephaly - The most common suture to fuse is the middle or sagittal suture. Often the back or front of the skull will be worse but the overall shape is a long skull with a shortened distance from ear to ear..

Pre-op	CAT scan	Diagram of surgery	2 years post-op
Patient with saggital synostosis and scuphocephaly

Multiple suture fusion - Occasionally more than one suture will be fused. The resulting head shape is dictated by the number and location of the suture. These cases usually require earlier intervention and careful monitoring of intracranial pressures on the brain.

Most babies with fusion of the skull suture will not have any other anomalies. Rarely, the suture fusion is related to a syndrome meaning a collection of other congenital amonalies, not directly related to the scull. Some of the syndromes have associated genetic mutations and may be hereditary while others are merely clinical diagnoses. The following are a few of the more common syndromes associated with craniosynostosis 1. Apert's syndrome - may have fusion of skull sutures, fusion of several fingers of the hands and feet, and small face with prominent eyes (midface hypoplasia and proptosis). Babies often have a very large soft spot on the forehead. 2. Crouzon syndrome - May be similar to Apert's in skull shape. Often has more prominent eyes and small midface and no hand or foot involvement. The soft spot is usually small or gone completely. 3. Pfeiffer's syndome - Similar to Crouzon's syndrome but with braod thumbs and great toes. 4. Saethre-Chotzen syndrome - may or may not have fusion of the cranial sutures. Upper lid droop and webbing of index and long fingers and fourth and fifth toes are common. External ear anomalies may also be present. Genetic testing is now available to comfirm the diagnosis in most cases.