Craniosynostosis

When skull bones fuse too early and the head shape changes

Important. This is general educational information. Your child's situation is unique. Always talk to your child's treating doctor for advice that fits your child specifically.

If your baby's head shape looks unusual, or if a doctor has told you that one of the seams in the skull has closed too early, this page explains what that means, how doctors decide whether it needs treatment, and what the surgery involves. The information here is general, your child's craniofacial team will discuss what applies specifically to your child.

What is craniosynostosis?

A baby's skull is not a single solid bone. It is made up of several bones with soft seams (called sutures) between them. The sutures allow the skull to stretch and grow as the brain expands underneath. Most of the sutures stay open until a child is at least a few years old.

Craniosynostosis happens when one or more of these sutures closes too early, in some cases even before the baby is born. Once a suture is fused, the skull can no longer grow across it. The brain underneath continues to grow normally, but it can only push the skull outward in the directions where the sutures are still open. The result is a head shape that is not the usual round shape.

There are several types of craniosynostosis depending on which suture is involved, and your child's team may use one of the following names:

Sagittal synostosis is the most common form. The suture that runs from front to back along the top of the head is closed. The head grows long from front to back but narrow from side to side. This is sometimes called scaphocephaly, or a "boat-shaped" head.

Metopic synostosis affects the suture running down the middle of the forehead. The forehead can look pointed or triangular, often with the eyes set slightly closer together. This is sometimes referred to as trigonocephaly.

Coronal synostosis affects a suture that runs across the top of the head from ear to ear. When only one side is fused, the forehead is flat on that side and the opposite side bulges. When both sides are fused, the head is wide and short.

Lambdoid synostosis is the rarest form. It affects a suture at the back of the head and produces a particular pattern of flattening posteriorly.

Most children with craniosynostosis have only one fused suture and are otherwise healthy. In a smaller number of children, multiple sutures are fused at once and there may also be features in the face, the hands or the feet. This is termed syndromic craniosynostosis, names you may hear include Apert, Crouzon, Pfeiffer, Saethre-Chotzen, and Muenke syndromes. These children are looked after by a larger team and may need more than one operation as they grow.

Signs you might notice

Many babies are diagnosed during routine well-baby visits when the doctor notices the head shape or feels along the sutures. Some are noticed by the parents first. One important point upfront, a flat spot on the back or side of the head is very often not craniosynostosis at all, see the note about positional flattening at the end of this section.

In babies

  • A head shape that is clearly not round, long and narrow side-to-side, pointed or triangular at the forehead, flat on one side of the forehead, or flat at the back
  • A ridge of bone that can be felt along one of the sutures
  • The anterior fontanelle closing earlier than expected, or feeling unusually firm
  • Head growth that is not progressing as expected at routine measurements
  • Eyes that look different in size, position or shape, or eyelids that do not close fully (in some syndromic cases)
  • In syndromic cases - additional differences in the face, the fingers or the toes that the team will examine carefully

In older children

  • An unusual head shape that has been present since infancy and has not changed
  • Forehead, eye, or facial differences that families and the child come to notice over time
  • In rare untreated or complex cases - morning headaches, vomiting, or visual changes that can suggest raised pressure within the head

How is it diagnosed?

The first and most important assessment is a careful examination by a doctor who knows what to look for, usually a paediatric neurosurgeon, a craniofacial surgeon, or a craniofacial team. The shape of the head, the position of the sutures, and the fontanelle all give important clues. In many babies the examination on its own is enough to make the diagnosis.

When imaging is required, a low-dose CT-scan of the skull is the test of choice. It shows the sutures clearly and confirms which one is fused. Modern protocols use a very small dose of radiation, and the scan is quick. In some centres, 3D ultrasound or specific MRI sequences are used first to avoid radiation altogether.

There is one very important condition that can look like craniosynostosis but is not - positional plagiocephaly, a flattening of the back or side of the head that occurs because a baby has spent a lot of time lying in one position. Positional flattening is very common, it does not affect the brain, and it does not need surgery. It is managed by changing positions, more tummy time, and sometimes a specially-fitted helmet. Your child's doctor will be able to tell the two conditions apart by examining the head shape and the sutures. If there is any doubt, an experienced craniofacial team should review the baby.

If craniosynostosis is confirmed and the team suspects a syndrome (because of additional features in the face, the hands or the feet, or because more than one suture is involved), a genetics consultation will be arranged and genetic testing may be recommended. This helps plan all the care your child may need over the years.

How is it treated?

When surgery is needed, the aim is to give the brain room to grow normally and to restore a normal head shape. There are two main surgical approaches, and the right one depends primarily on your baby's age, on which suture is fused, and on which option is offered at your centre. Most non-syndromic craniosynostosis is treated within the first year of life, earlier is usually easier on the baby.

Endoscopic strip craniectomy + helmet

A minimally invasive operation performed through one or two small cuts in the scalp. The neurosurgeon uses a small camera (an endoscope) to remove a strip of bone along the fused suture, which allows the head to grow back into a normal shape over the following months. After the surgery, your baby will wear a custom-fitted helmet for several months (usually 6 to 12) to guide the head shape as it grows. This approach gives smaller scars, less blood loss, a shorter hospital stay and a faster recovery, but it works best when performed early, typically before the baby is about 4 to 6 months old.

Open cranial vault remodeling

In this operation the craniofacial team makes a longer (often zig-zag) cut across the top of the scalp, removes the affected pieces of skull, and reshapes them carefully before fixing them back in their new position with small dissolvable plates and screws. It is a bigger operation, typically a few hours long, with a blood transfusion usually needed and a hospital stay of several days, but it does not require a helmet afterwards, and it works well for babies who are too old for the endoscopic approach (generally after about 6 months) or for more complex cases.

Spring-assisted and distraction techniques

Some centres use small metal springs or a slow stretching device (distractor) to gradually reshape the skull over weeks. These techniques are less common, are best suited to specific situations, and require a second small operation to remove the device. The team will tell you whether this is an option for your child.

Surgery for syndromic craniosynostosis

Children with syndromic craniosynostosis often need more than one operation as they grow. The first operation in infancy is similar to the ones described above. Later operations may address the middle part of the face (a midface advancement) to help breathing, the position of the eyes, and bite alignment. The exact plan is highly individual and is discussed in detail by the craniofacial team.

When surgery is not needed

Not every unusual head shape needs surgery. If the sutures are open and the shape is from positioning (positional plagiocephaly), no operation is required, positioning changes, tummy time, and sometimes a helmet are enough. The team will explain clearly which situation your baby is in.

Craniofacial surgery is a highly specialised field. Your baby will be cared for by a team that usually includes a paediatric neurosurgeon, a craniofacial plastic surgeon, anaesthesia, ophthalmology, ENT, dentistry/orthodontics (later on), genetics (if syndromic), and a nurse coordinator. If a syndrome is suspected, a centre experienced in syndromic craniosynostosis is the right place for your child's care.

What can we expect?

After endoscopic surgery, most babies spend one or two nights in hospital and go home soon afterwards. After open cranial vault remodeling, the stay is usually three to five nights, with the first night in the paediatric intensive care unit. In both cases, swelling and bruising around the eyes is expected and can look dramatic for the first few days, your baby's eyes may be almost swollen shut for a short period. This always settles over about a week.

Most babies are back to normal feeding and behaviour within two to three weeks. The head shape continues to improve for many months as the skull keeps growing. Photos taken at one month, six months and one year usually show clear changes you can see for yourself.

If your baby needs a helmet after the endoscopic surgery, it is fitted by an orthotist and changed every few months as the head grows. The helmet is worn 23 hours a day, with breaks for bathing and a short out-of-helmet time each day. It is hard work for families at first, but most babies tolerate the helmet well and the results are excellent.

In the long term, most children with non-syndromic single-suture craniosynostosis grow up with normal development, a good head shape, and no further surgery needed. Follow-up generally continues for a few years to check head growth, vision and development. Children with syndromic craniosynostosis are followed by the craniofacial team into adolescence and sometimes into adulthood, with operations planned at the ages where they make the most difference.

Most parents are anxious before the surgery and relieved afterwards. Talking with the team, with families who have been through it, and with patient organisations dedicated to craniofacial conditions can make the journey easier.

Questions you might ask your child's doctor

  • Which suture (or sutures) is fused in my child, and what is the name of this type of craniosynostosis?
  • Is this isolated craniosynostosis, or could it be part of a syndrome? Do you recommend a genetics consultation?
  • Do you recommend endoscopic surgery with a helmet, or open cranial vault remodeling, and why for our child specifically?
  • What is the best age for our child's operation, and what happens if we wait?
  • How long will our child be in hospital, and what will the first week at home look like?
  • What are the risks of this operation, including bleeding, the need for transfusion, infection and the anaesthetic risks?
  • If a helmet is part of the plan, how does it work, how long is it worn, and how is it fitted and adjusted?
  • What is the long-term plan, how often will follow-up appointments be, and what will you be watching for?
  • Are there any signs at home that should prompt us to call you urgently?
  • Are there families or organisations you can connect us with for support?

When to call your child's doctor right away

After craniosynostosis surgery, most recovery is smooth. But some signs need to be looked at quickly. Do not wait, contact the craniofacial team (or go straight to the emergency department) right away if you notice any of the following:

  • Redness, swelling, fluid leaking, or pain along the scar
  • A fever, particularly in the first two weeks after the surgery
  • Worsening swelling around the eyes after the first week (when it should be getting better, not worse)
  • Repeated vomiting that does not stop, or refusal to feed
  • Unusual drowsiness, difficulty rousing, or unusual irritability
  • A seizure
  • A bulging or tense fontanelle that was not there before
  • Eyes that do not close properly, or new concerns about your baby's vision
  • Any change in breathing, particularly in babies with syndromic craniosynostosis who can have airway issues

If your child is difficult to rouse, is having a seizure, or is having difficulty breathing, this is an emergency, go to the nearest emergency department or call the emergency services immediately.

More information from trusted sources

  • Children's Craniofacial Association (CCA) — A US-based non-profit supporting families of children with craniofacial differences, with educational booklets on the major types of craniosynostosis and craniofacial syndromes, as well as family events.
    https://ccakids.org ↗
  • FACES: The National Craniofacial Association — A US-based organisation providing financial assistance and information to children and families affected by craniofacial conditions, including travel grants for specialised care.
    https://www.faces-cranio.org ↗
  • Headlines Craniofacial Support (UK) — A UK-based charity dedicated to families affected by craniofacial conditions including craniosynostosis, with information, a helpline, and family meet-ups.
    https://www.headlines.org.uk ↗
  • American Association of Neurological Surgeons — Patient Information — The patient education pages of the professional society, including overviews of craniosynostosis written in plain language.
    https://www.aans.org/Patients/Neurosurgical-Conditions-and-Treatments ↗
  • HealthyChildren.org (American Academy of Pediatrics) — Trusted patient and family information from the American Academy of Pediatrics, with practical guidance on positional plagiocephaly versus craniosynostosis and on protecting infants' head shape.
    https://www.healthychildren.org ↗