Craniosynostosis

ByJoan Pellegrino, MD, Upstate Medical University
Reviewed/Revised Jul 2024
VIEW PROFESSIONAL VERSION

Craniosynostosis is a birth defect in which one or more of the skull's sutures close too early.

Birth defects, also called congenital anomalies, are physical abnormalities that occur before a baby is born. "Congenital" means "present at birth." (See also Introduction to Birth Defects of the Face and Skull.)

Sutures of the Skull

The sutures are bands of tissue that connect the bones of the skull. The sutures allow the skull to grow as the brain grows inside.

The sutures are bands of tissue that connect the different bones that make up the skull. The skull is not a single bone. The sutures allow the skull to grow as the brain grows inside. They remain flexible for several years after birth and close and harden as the baby grows. After the sutures close, the skull cannot grow any more.

Craniosynostosis results when these sutures close too early, which restricts the ability of the brain and skull to grow to a normal shape and size. Craniosynostosis may occur spontaneously or may be caused by mutations in the baby's genes.

This defect occurs in 1 in every 2,500 babies. There are several types of craniosynostosis, depending on which suture is closed.

Sagittal craniosynostosis

Craniosynostosis of the sagittal suture (the suture on top of the head running from the baby's fontanelle or soft spot to the back of the head) is the most common type. This type of craniosynostosis results in a narrow and long skull (dolichocephaly).

About 20 to 50% of children who have this type of craniosynostosis develop learning disabilities.

Craniosynostosis of the Sagittal Suture (Sagittal Craniosynostosis)
Hide Details
These photos show a 6-week-old infant who has craniosynostosis of the sagittal suture (sagittal craniosynostosis), which causes a narrow and long skull (dolichocephaly).
© Springer Science+Business Media

Coronal craniosynostosis

Craniosynostosis of the coronal sutures (the sutures running across the head to the left and right of the soft spot) is the next most common type. This type of craniosynostosis results in a short and broad skull if the sutures on both sides of the soft spot are closed (brachycephaly) or in a diagonal skull if the sutures on only one side of the soft spot are closed (plagiocephaly). Children who have this type of craniosynostosis often have other defects of the face and skull.

Craniosynostosis of the Left Coronal Suture (Coronal Craniosynostosi...
Hide Details
This image shows a 10-week-old infant who has craniosynostosis of the left coronal suture. This defect has caused the right side of the forehead to appear more prominent and the eyes to be uneven.
© Springer Science+Business Media

Diagnosis of Craniosynostosis

  • A doctor's evaluation

  • Sometimes imaging tests such as CT scan

  • Sometimes genetic testing

Doctors can identify craniosynostoses during a physical examination.

Doctors may also do imaging tests of the skull and brain.

A baby who has craniosynostosis may be evaluated by a geneticist. A geneticist is a doctor who specializes in genetics (the science of genes and how certain qualities or traits are passed from parents to children). Genetic testing of a sample of the baby's blood may be done to look for chromosome and gene abnormalities. This testing can help doctors determine whether a specific genetic disorder is the cause and rule out other causes.

Treatment of Craniosynostosis

  • Surgery

  • Special helmet

Craniosynostoses are usually corrected with surgery. After surgery, babies often wear a special helmet to help mold their skull into a more regular shape.

Because abnormal genes may be involved in the formation of craniosynostoses, affected families may benefit from genetic counseling.

quizzes_lightbulb_red
Test your KnowledgeTake a Quiz!
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID