Craniosynostosis occurs when one or more of the bone plates in the skull fuse early.

The skull is made up of several plates of bone. In a baby these plates are not supposed to be fused together as they are in an adult. This makes giving birth easier, as the plates can move when the baby goes through the birth canal. It also allows a baby’s brain to grow after the birth.

Craniosynostosis occurs when one or more of the plates have fused together earlier than they should have. The site of the fusion is called a suture. The baby’s brain still needs to grow and it cannot grow in all directions if the sutures are fused too early. The brain grows in the direction of the non-fused sutures. This gives people with craniosynostosis an unusual-shaped head. If the fusion occurs before the baby is born it can sometimes be seen on an ultrasound during pregnancy. If a baby is going to develop craniosynostosis, it usually occurs in the first year of life and is very unlikely to occur after the age of 2 or 3 years.

What causes craniosynostosis?

There are several causes of craniosynostosis and not all are known. It is known that some cases are due to a gene change in the baby and other cases are non-genetic. It is also known that mothers who take certain medications while pregnant are at increased risk of having children with craniosynostosis.

Can anything be done to correct the craniosynostosis?

Surgery can reopen the closed sutures. This can be done in the first year of life. More than one surgery may be required depending on how many sutures are fused and how long they have been fused.

Will my child have other problems?

Craniosynostosis can occur in isolation, in a child with no other medical problems. Even if the brain is not the usual shape, it still is fully formed and so there is no brain damage from being a different shape. The risk of brain damage occurs if the brain does not have room to grow. Pressure from the skull can cause damage to the brain. It is important to get a medical care if a child with craniosynostosis has frequent headaches, as this may indicate that there is pressure on the brain from the skull.

Craniosynostosis can also occur as part of a syndrome. The percentage of children with craniosynostosis that have a syndrome is around 20%. This percentage can be higher depending upon which sutures are involved. About 70 syndromes have craniosynostosis as one of their features.

Can more than one child in a family have craniosynostosis?

If the craniosynostosis occurred in isolation, the chance of it happening in another pregnancy depends on the sutures involved and the family history. For families that want more information, genetic counseling is advised. If the craniosynostosis is part of a syndrome, the reoccurrence risk (chance of it happening again in another child) varies depending on the syndrome, because different syndromes are inherited in different ways.


  • Gorlin R.J., Cohen M.M., Hennekam R.C.: Syndromes of the Head and Neck. Oxford University Press, 1990.