Craniosynostosis

In this condition, one or more of the flexible joints between the bone plates of a baby's skull close before the brain is fully formed.

Update Date: 01.08.2025

Overview

Craniosynostosis (kray-nee-o-sin-os-TOE-sis) is a condition present at birth. It causes one or more of the joints between the bones of a baby's skull to close too early, before the brain is fully formed.

A baby's skull is made up of small plates of bone connected by flexible, fibrous joints called sutures. The sutures allow a baby's skull to get bigger as the brain grows. The sutures usually close when the brain is done growing.

Craniosynostosis usually involves early closing of one cranial suture but can involve more than one. Brain growth continues even when one or more sutures close too early. Open sutures on other sides of the head allow brain growth in those directions. This causes the head to have a shape that's not typical.

Treating craniosynostosis involves surgery to reshape the skull. Early diagnosis and treatment allow the baby's brain enough space to grow and develop.

After surgery, most children develop as expected and have a more average shape to the face and head.

Cranial sutures and fontanels

Joints called cranial sutures are made of flexible, fibrous tissue. They hold the bones of a baby's skull together. The sutures meet at the fontanels, the soft spots on a baby's head. The sutures remain flexible during infancy. This allows the skull to grow as the brain grows. The largest fontanel, called the anterior fontanel, is at the front.

Symptoms

Symptoms of craniosynostosis usually can be seen at birth. They become easier to see during the first few months of a baby's life.

Symptoms and their severity depend on how many sutures are closed and when the closing occurs during brain development. Symptoms can include:

  • A skull with a shape that's not typical. Shape depends on which of the sutures are closed. The brain keeps growing on the sides with open sutures, changing the shape of the head.
  • Change in the balance of facial features and ears. For example, one eye may be higher than the other.
  • A raised, hard ridge along the closed cranial suture.

Types of craniosynostosis

On the top of the head toward the front, some sutures meet at the large soft spot called the anterior fontanel. The anterior fontanel is the soft spot felt just behind a baby's forehead. The next largest fontanel, called the posterior fontanel, is at the back of the head where the other sutures meet. The flexible, fibrous sutures connect the bony plates of the skull.

The term given to each type of craniosynostosis depends on which sutures are affected. Types of craniosynostosis include:

  • Sagittal. The sagittal suture runs from front to back at the top of the skull between the front and back fontanels. When the sagittal suture closes too early, it forces the head to grow long and narrow. Sagittal craniosynostosis is the most common type of craniosynostosis.
  • Coronal. Coronal sutures run from each ear to the top of the skull, meeting at the front fontanel. When only one coronal suture closes too early, it may cause the forehead to flatten on that side and bulge on the other side. It also causes the nose to turn and the eye socket to rise on the affected side. When both coronal sutures close too early, the head looks short and wide, often with the forehead tilted forward.
  • Metopic. The metopic suture runs up from the top of the bridge of the nose through the middle of the forehead to the front fontanel. When the metopic suture closes too early, the forehead has a triangular shape and the back part of the head widens.
  • Lambdoid. The lambdoid suture runs down the back of the head from the back fontanel. When the lambdoid suture closes too early, it may cause one side of a baby's head to appear flat, one ear to be higher than the other ear and the top of the head to tilt to one side. Early closing of the lambdoid suture is a very rare type of craniosynostosis.

Other reasons for a changed head shape

A head shape that's not typical doesn't always mean that a baby has craniosynostosis. For example, if the back of your baby's head appears flattened, it could be the result of spending too much time lying on the back. This can be treated with regular position changes. If the head is very flat on one side, helmet therapy can help reshape the head to a more balanced look.

When to see a doctor

Your pediatrician or other healthcare professional monitors your child's head growth at well-child visits. Talk with your healthcare professional if you have concerns about your baby's head growth or shape.

Causes

Often the cause of craniosynostosis is not known. But sometimes it's related to genetic conditions.

  • Nonsyndromic craniosynostosis is the most common type. Its cause is not known, but it's thought to be a mix of genetic and environmental factors.
  • Syndromic craniosynostosis is caused by certain gene changes that cause genetic syndromes. Examples include Apert syndrome, Pfeiffer syndrome and Crouzon syndrome. These syndromes can affect a baby's skull development. They usually also include other physical changes and health conditions.

Risk factors

Genetic syndromes that affect a baby's skull development, such as Apert syndrome, Pfeiffer syndrome and Crouzon syndrome, are risk factors for craniosynostosis.

Complications

If not treated, craniosynostosis may cause:

  • Lasting changes in the shape of the head and face.
  • A feeling of not being worthy and of wanting to stay away from others.

The risk of higher pressure inside the skull, called intracranial pressure, from craniosynostosis is small if the suture and head shape are treated with surgery. Babies who have craniosynostosis caused by a genetic syndrome may develop higher pressure inside the skull if treatment doesn't make the skull larger to make room for their growing brains.

If not treated, higher pressure inside the skull can cause:

  • Developmental delays.
  • Problems with thinking, memory and learning.
  • Blindness.
  • Seizures.
  • Headaches.

Diagnosis

Craniosynostosis is usually diagnosed by specialists, such as pediatric neurosurgeons or specialists in plastic and reconstructive surgery. Diagnosis of craniosynostosis may include:

  • Physical exam. Your healthcare professional feels your baby's head for suture ridges and looks for changes in facial features and head shape.
  • Imaging studies. A computerized tomography (CT) scan and magnetic resonance imaging (MRI) of your baby's skull can show whether any sutures have fused. Cranial ultrasound imaging may be used. Sutures can't be seen after they've closed, so not seeing sutures means that they're closed. Imaging studies also may show a ridging of the suture line. Results of imaging studies, a laser scan and photographs may be used to make precise measurements of the skull shape. These measurements also are used to plan surgery.
  • Genetic testing. If your healthcare professional suspects that craniosynostosis is part of a genetic syndrome, genetic testing may help identify the syndrome.

Rarely, craniosynostosis may be suspected or diagnosed before birth.

Treatment

Your child's care team may include a variety of specialists who are experts in managing craniosynostosis. At a center with expertise in diagnosing and treating craniosynostosis, these specialists work together in one place.

Mild craniosynostosis may not need treatment with surgery.

For most babies, surgery is the main treatment. The type of surgery and when it's done depends on the type of craniosynostosis and whether it's part of a genetic syndrome. Sometimes more than one surgery is needed.

The purpose of treatment is to reshape the head, lessen or prevent pressure on the brain, and create room for the brain to grow properly. This process involves planning and surgery.

Surgical planning

Imaging studies can help surgeons create a surgical plan. Virtual surgical planning for treatment of craniosynostosis uses high-definition 3D CT scans and MRI scans of your baby's skull to create a computer-simulated surgical plan specific to your baby's needs. Based on that virtual surgical plan, customized models and templates are made to guide the procedure.

Surgery

A team that includes a specialist in surgery of the head and face, called a craniofacial surgeon, and a specialist in brain surgery, called a neurosurgeon, usually do the surgery. Surgery can be done with endoscopic or open surgery. The exact surgery and when it's done depend on which and how many sutures have closed. Both types of procedures generally have very good cosmetic results with low risk of complications.

  • Endoscopic surgery. This minimally invasive surgery may be considered for babies up to age 6 months. It's better to have the surgery done as soon as possible. A lighted tube and camera called an endoscope is inserted through small scalp cuts, also called incisions. The surgeon removes the closed suture to allow the skull to expand with the baby's brain growth. Compared with an open surgery, endoscopic surgery has smaller incisions, typically involves only a one-night hospital stay and usually does not need blood transfusion.
  • Open surgery. Generally, open surgery is done for babies older than 6 months. The surgeon makes a cut in the scalp and cranial bones. Then the surgeon reshapes the skull to allow more room for the brain to grow. The skull position is held in place with plates and screws that dissolve on their own over time. Open surgery typically involves a hospital stay of 3 to 4 days. Blood transfusion is usually needed. Open surgery is generally a one-time procedure, but in babies with complex craniosynostosis, more open surgeries are often needed to reshape the head.

To help widen the space between the skull bones once a closed suture has been removed, springs may be placed in the gap. Called spring-mediated cranioplasty, placement of the springs can be done as part of open surgery or endoscopic surgery. Another surgery is needed to remove the springs.

Helmet therapy

After minimally invasive surgery, your baby has regular office visits to fit a series of helmets to help shape the skull. The surgeon talks with you about how long helmet therapy is needed based on how quickly the head shape responds to treatment. Usually a baby wears a helmet 23 hours of each day for about a year. If open surgery is done, usually no helmet is needed afterward.

Coping and support

When you learn that your baby has craniosynostosis, you may have a range of emotions. You may not know what to expect. Information and support can help.

To help you prepare and care for your baby:

  • Find a team of trusted professionals. You'll likely need to make important decisions about your baby's care. Medical centers with craniofacial specialty teams can offer you information about the condition, coordinate your baby's care among specialists, help you look at treatment options and give treatment.
  • Seek out other families. Talking with people who are dealing with the same kinds of challenges can give you information and emotional support. Ask your healthcare professional about support groups in your community. If an in-person group isn't for you, your healthcare professional may put you in touch with a family who has a child with craniosynostosis. Or you may be able to find group or individual support online.
  • Stay positive. Most children develop as expected and have good cosmetic results after surgery. Early diagnosis and treatment are key. When needed, early intervention services offer help with developmental delays or intellectual disabilities.

Preparing for an appointment

Sometimes a pediatrician may suspect craniosynostosis at a routine well-baby visit. Or you may make an appointment because you have concerns about your baby's head growth. Your healthcare professional can refer you to a specialist for diagnosis and treatment.

Here's some information to help you get ready for your appointment. If possible, take a family member or friend with you. That person can help you remember information and give emotional support.

What you can do

Before the appointment, make a list of:

  • Any symptoms you've noticed, such as raised ridges or a change in the shape of your baby's face or head.
  • Questions to ask your healthcare professional.

Questions to ask might include:

  • What's the most likely cause of my baby's symptoms? Are there other possible causes?
  • What kinds of tests does my baby need? Do we need to do anything to get ready for these tests?
  • What treatments are available? Which do you suggest?
  • Are there other treatment options?
  • What are the risks with surgery?
  • Who will do the surgery if it's needed?
  • What happens if we choose not to have the surgery right now?
  • Will the shape of the skull affect my baby's brain?
  • What are the risks that future children will have the same condition?
  • Are there brochures or other printed material that I can have? What websites do you suggest?

Feel free to ask other questions during the appointment.

What to expect from your doctor

Your healthcare professional is likely to ask you questions, such as:

  • When did you first notice the changes in your baby's head shape?
  • How much time does your baby spend lying on the back?
  • In what position does your baby sleep?
  • Is your baby's development like that of other children of the same age?
  • Were there any complications during your pregnancy?
  • Do you have a family history of craniosynostosis or genetic conditions such as Apert syndrome, Pfeiffer syndrome or Crouzon syndrome?

Be ready to answer questions so that you have time to talk about what's most important to you.

© 2025 Mayo Foundation for Medical Education and Research. All rights reserved. Terms of Use