Symptoms and Causes of Craniosynostosis in Children

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Learning more about craniosynostosis can help you better understand what to expect during your child's treatment. A good starting point is to visualize the basic structures in a newborn's skull.


  • An infant’s skull has several plates of bone that are separated by fibrous joints, called sutures.
  • The sutures gradually close as the child grows and develops.
  • When the sutures close, the skull is fully formed as a solid piece of bone. 

When a child has craniosynostosis:

  • The sutures close too early.
  • The pressure inside the skull, or intracranial pressure, can become elevated.
  • The skull and facial bones may become visibly deformed or asymmetrical.
  • The brain and skull may develop abnormally. 

If untreated, craniosynostosis can lead to serious problems, including:

  • developmental delays
  • problems with learning, memory, speech and communication
  • severe nausea and vomiting
  • seizures

Craniosynostosis is a potentially progressive condition, meaning that, if it is not treated, symptoms can continue, and possibly worsen, over time. As a result, surgery is recommended for most children with craniosynostosis.

Did you know?

Boston Children’s neurosurgery, neurology programs are ranked #1 by U.S. News & World Report

Signs and symptoms of Craniosynostosis

What are the symptoms of craniosynostosis?
Symptoms of craniosynostosis may vary, depending upon:

  • the type of craniosynostosis
  • the age of the child at diagnosis
  • which sutures in the skull are involved
  • how advanced the condition is when discovered 

The most common signs that a child may have craniosynostosis include:

  • an unusually shaped head or face
  • asymmetrical appearance of the head or skull (one side of the face or top of the head looks different than the other)
  • an enlarged appearance of the head or skull
  • a bulging fontanelle ( the “soft spot” at the top of a newborn’s skull)
  • bulging eyes 

You should seek treatment from a qualified medical professional right away if you notice several of these warning signs in your child. Early intervention is key to successfully treating craniosynostosis and preventing serious problems.

Types of Craniosynostosis

There are several different forms of craniosynostosis, namely: 

  • sagittal suture craniosynostosis; this is the most common type. Babies with this form of craniosynostosis experience premature closing of the sagittal suture, which divides the parietal bones (the bones that make up the top and sides of the head). This causes a narrowed, elongated head appearance, called scaphalocephaly.
  • unilateral coronal synostosis, which causes fused skull bones along what is known as the coronal suture. This suture runs from the ear to the baby’s fontanelle, or “soft spot,” on either the right or left side. Unilateral coronal synostosis prevents the forehead and brow bone from developing normally.
  • trigonocephaly, which involves the fusion of the metopic suture (running from the top of the head down the forehead to the top of the nose).  Children with this type of craniosynostosis may have a prominent ridge along their foreheads, and their skulls may have a pointed, slightly triangular appearance in front.


What causes craniosynostosis?

Craniosynostosis often occurs randomly—meaning there’s no clear reason why a child develops the disorder. 

In some cases, craniosynostosis is caused by an inherited genetic problem. When craniosynostosis is inherited, typically:

  • One parent has what is called anautosomal dominant gene for craniosynostosis. This means that there is a 50 percent chance of having a child with craniosynostosis, even if the parent is not directly affected by the condition.

Frequently Asked Questions (FAQ) about Craniosynostosis

Q: Will my child be OK?
A: The severity of craniosynostosis can vary widely, depending on:

  • the type of craniosynostosis
  • the specific sutures and parts of the skull involved
  • the age of your child at diagnosis
  • the overall health of your child
  • the symptoms already present at diagnosis 

Some forms of craniosynostosis—particularly in children who are diagnosed when the condition is already pronounced—can cause elevated intracranial pressure (and delays in brain development, leading to problems with learning, speech and other functions). 

The key factor in successfully treating the condition is early detection and prompt, medical attention. The earlier craniosynostosis is diagnosed and treated, the better the general outlook for the child. 

Q: How common is craniosynostosis?
A: It affects about one in every 2,500 children. 

Q: At what age does craniosynostosis tend to develop?
A: Physicians can sometimes detect craniosynostosis in fetuses as early as the 12th week of a woman’s pregnancy, but prenatal diagnosis is very uncommon. Craniosynostosis is almost always noticeable at birth, although some children’s conditions may not be detected until later in infancy.

Q: Is my baby going to need surgery?
A: Most children with craniosynostosis will need surgery to prevent further problems with their brain and skull growth and to correct deformities in their skulls’ structures. Here at Children’s Hospital Boston, our clinicians have extensive experience performing surgeries for all types of craniosynostosis, and most children who have these procedures go on to lead fulfilling, active adult lives. 

Q: What do I need to look out for once my child has been diagnosed with craniosynostosis?
Parents of children with craniosynostosis should always be watchful for changes in their child’s:

  • head shape and size
  • movement
  • activity levels
  • temperament
  • appetite
  • cognitive functioning (memory, learning, speech and language) 

Q: Is there a cure for craniosynostosis?
A: Craniosynostosis can be a progressive condition, meaning that, if it is not treated, symptoms can continue—and possibly worsen—over time. As a result, for most children with craniosynostosis, surgery will eventually become necessary.

The good news is that the surgical techniques used at Children’s have an excellent success rate for correcting the deformities of the head and skull in children with craniosynostosis, and can help prevent further problems with brain and skull growth.

Did you know?

Boston Children’s offers counseling for families with known, suspected inherited conditions

Questions to ask your doctor

You and your family play an essential role in your child’s treatment for craniosynostosis. It’s important that you share your observations and ideas with your child’s treating physician, and that you have all the information you need to fully understand the treatment team’s explanations and recommendations. 

You’ve probably thought of many questions to ask about your child’s craniosynostosis. It’s often very helpful to jot down your thoughts and questions ahead of time and bring them with you, along with a notebook, to your child’s appointment. That way, you’ll have all of your questions in front of you when you meet with your child’s treating clinician and can make notes to take home with you.
Some questions to ask your doctor might include:

  • How did you arrive at this diagnosis?
  • Are there any other conditions my child might have in addition, or instead?
  • What type of craniosynostosis does my child have?
  • How advanced is my child’s craniosynostosis?
  • Is my child's craniosynostosis possibly inherited? If so, can you refer me to genetic counseling services for my family?
  • What is the long-term outlook for my child?
  • Is surgery necessary at this time?
  • Do I need to restrict my child’s physical activity?
  • Does my child need to wear a protective helmet?
  • Do I need to make any other changes to my child’s daily routines?
  • How should I explain my child’s condition to others?
  • What other resources can you point me to for more information?
Did you know?

Boston Children’s neurosurgery, neurology programs are ranked #1 by U.S. News & World Report

Did you know?

Boston Children’s neurosurgery, neurology programs are ranked #1 by U.S. News & World Report

Did you know?

Boston Children’s neurosurgery, neurology programs are ranked #1 by U.S. News & World Report

Did you know?

Boston Children’s neurosurgery, neurology programs are ranked #1 by U.S. News & World Report

Did you know?

Boston Children’s neurosurgery, neurology programs are ranked #1 by U.S. News & World Report

We are grateful to have been ranked #1 on U.S. News & World Report's list of the best children's hospitals in the nation for the third year in a row, an honor we could not have achieved without the patients and families who inspire us to do our very best for them. Thanks to you, Boston Children's is a place where we can write the greatest children's stories ever told.”
- Sandra L. Fenwick, President and CEO

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