Craniosynostosis is a congenital (present at birth) defect that causes one or more sutures on a baby's head to close earlier than normal. Sutures are connections that separate each individual skull bones. The early closing of a suture leads to an abnormally shaped head.

The cause of craniosynostosis is unknown. Which suture is involved determines the abnormal shape of the head.

A person's genes may play a role in craniosynostosis. The hereditary form often occurs with other defects that can cause seizures, diminished intellectual capacity, and blindness. Genetic disorders commonly associated with craniosynostosis include Crouzon, Apert, Carpenter, Chotzen, and Pfeiffer syndromes.

However, most cases of craniosynostosis occur in a family with no history of the condition and children with craniosynostosis are otherwise healthy and have normal intelligence.

There are different types of craniosynostosis. Sagittal synostosis (scaphocephaly) is the most common type. It affects the main (sagittal) suture on the very top of the head. The early closing forces the head to grow long and narrow, instead of wide. Babies with this type of craniosynostosis tend to have a broad forehead. It is more common in boys than girls.

Frontal plagiocephaly is the next most common form. It is the closure of one side of the suture that runs from ear to ear on the top of the head. It is more common in girls.

Metopic synostosis is a rare form of craniosynostosis that affects the suture close to the forehead. The child's head shape may be described as trigonocephaly, and the deformity may range from mild to severe.

• Absence of the normal feeling of a "soft spot" (fontanelle) on the newborn's skull
• Disappearance of the fontanelle early
• A raised hard ridge along the affected sutures
• Unusual head shape
• Slow or no increase in the head size over time as the baby grows

The doctor will feel the infants head and perform a physical exam. A neurological exam would also help diagnose the condition. The following tests may be performed:

• Measuring the width of the infant's head
• X-rays of the skull
• CT scan of the head