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What Is Craniosynostosis?

Craniosynostosis is when one or more seams between bones in a child's skull close too soon. When this happens, the skull can't grow properly, and develops a different shape.

What Happens in Craniosynostosis?

Babies' skulls are made of several bones that fit together like a puzzle. At birth, the borders between the bones (called cranial sutures) are not yet solid. This lets the skull expand, leaving the "soft spot" (or fontanelle).

Normally, cranial sutures:

  • flex and squeeze together a little, so that a baby's head can fit through the mother's pelvis during childbirth
  • let the skull expand to make room for the baby's rapidly growing brain
  • remain open until the third decade of life (when someone is in their twenties). The mid-forehead suture (the metopic suture) is the only exception, and it normally closes within the first year of life.

But in craniosynostosis (kray-nee-oh-sin-oss-TOE-sis), one or more sutures close too soon, either before birth or within a few months after. Craniosynostosis that's not corrected can cause pressure inside the skull (intracranial pressure). If it’s not treated, the increased intracranial pressure can lead to developmental problems, headaches, brain damage, or blindness.

What Are the Signs & Symptoms of Craniosynostosis?

Kids with craniosynostosis have an irregular head shape. Their head may look smaller, longer, wider, or more narrow than usual. Or, the two sides of the head may be uneven.

Parents or doctors may not notice a baby has an unusual head shape until a few weeks after birth. That's because it's normal for a baby's head to change shape in the early weeks of life.

A baby with craniosynostosis may show signs of a more urgent problem, such as:

  • inconsolable crying or fussiness
  • being very sleepy or not very active
  • a bulging fontanel (soft spot) on the top of the head
  • not feeding well
  • long pauses in breathing at night
  • regular bouts of vomiting (more than just a little baby “spit-up”)

What Causes Craniosynostosis?

Doctors don't always know why a child has craniosynostosis. Single-suture craniosynostosis is most common, and usually happens just by chance. When more than one suture fuses too soon, or when the craniosynostosis happens along with with other birth differences (facial differences, fused fingers or toes, heart problems, etc.), doctors may suspect a and recommend genetic testing.

How Is Craniosynostosis Diagnosed?

Sometimes, doctors see craniosynostosis on ultrasound scans before a baby is born. Other times, they find the condition when a baby is born or a few weeks later.

If doctors think a baby might have craniosynostosis, they may order tests, such as X-rays or a computed tomography (CT) scan. Then, they'll work with a neurosurgery team or a craniofacial team to confirm the diagnosis.

How Is Craniosynostosis Treated?

Often, a team of doctors works together to find the best treatment for a child with craniosynostosis. The team may include specialists in:

Babies with craniosynostosis usually need surgery during their first year of life. The main goal of surgery is to protect the developing brain and give it plenty of room to grow. A secondary goal is to provide a more normal head shape. A neurosurgeon and a craniofacial surgeon will work together to remove the fused suture(s) and to remodel and expand the surrounding skull bones.

Babies who are diagnosed with craniosynostosis early (within the first several weeks of life) might be able to have minimally invasive surgical treatment. Children diagnosed later typically need more extensive surgery to remodel and expand the skull bones.

Babies who have surgery for craniosynostosis usually recover quickly and do well. Patients with more complex patterns of craniosynostosis or those who are affected by a syndrome may need multiple operations as they grow.

How Can Parents Help?

A baby with craniosynostosis needs regular checkups. During visits, the doctor will examine your baby and pay close attention to your child's development. The doctor will tell you if your child needs regular eye exams and other care to help with learning.

It is important to find a specialized craniofacial team to care for your child. Ask your doctor for recommendations. Or search online at:

It also can help to talk with other parents who have a child with craniosynostosis. Ask your doctor to recommend a local support group, or look online at:

Medically reviewed by: Brian C. Kellogg, MD
Date reviewed: June 2023