Craniosynostosis (syndromic) factsheet

Introduction 

Syndromic craniosynostosis is complex and rare. It is characterised by the fusion (merging together) of multiple sutures (hold bones together). 

Patients experience issues involving brain development, vision, breathing and neurodevelopment. Many require a series of operations throughout their childhood. 

Multisuture craniosynostosis - This may be part of a syndrome, where other parts of the skull and body are affected (eg webbing/fusion of the fingers, hearing loss, cleft palate and underdevelopment of the cheekbones). 

Biicoronal craniosynostosis (most common) - This is where both coronal sutures are fused – the face and forehead will be symmetrical, but the head looks “short” when viewed from the side. 

Pan synostosis - This is when all the cranial sutures (tissue that connects the bones of the skull) are fused in children with syndromic craniosynostosis. 

 Signs and symptoms

Here's what to look out for in the types of syndromic craniosynostosis and rare genetic disorders:

  • Muenke Syndrome 

Muenke syndrome is the most common type of syndromic craniosynostosis. It is characterised by bicoronal craniosynostosis (both sides of the baby's head close too early) which is associated with hearing loss and problems with the joints of the arm. Intellectual development is usually normal. 

  • Crouzon Syndrome 

Crouzon syndrome is characterised by bicoronal craniosynostosis and under-developed cheek bones. The hands and intellectual functions are normal. Children with this condition need to be monitored for delayed onset of increased intracranial pressure. 

  • Apert Syndrome 

Apert Syndrome is characterised by bicoronal craniosynostosis, widely spaced eyes, under-developed cheek bones, a cleft palate, and fused fingers and toes, known as syndactyly. 

Beyond the visible physical characteristics, children with Apert Syndrome may experience dental issues and intellectual challenges. 

  • Pfeiffer Syndrome 

Affected children may be bicoronal or pan-synostosis. Signs include broad and short thumbs and under-developed cheek bones, hearing loss and developmental delay. 

  • Saethre-Chotzen Syndrome 

Saethre Chotzen syndrome is characterised by uni- or bi-coronal craniosynostosis, low set ears, ptosis (drooping) of the upper eyelids, fusion of the fingers and low hairline. 

  • Antley-Bixler Syndrome 

Antly-Bixler Syndrome is associated with multi-suture craniosynostosis and under-developed cheek bones. Children with Antley-Bixler Syndrome may have an airway blockage at the back of the nose called “choanal atresia” that requires early surgery.

There may be issues with the joints of the arms, internal organs (especially the urinary tract) and the way steroids are created and used within the body. 

  • Carpenter Syndrome 

Carpenter Syndrome occurs in children with multi-suture craniosynostosis. Patients have underdeveloped cheekbones, low set ears, dental issues, fusions of the skin between the fingers and toes, and commonly extra fingers and toes. 

Diagnosis

Craniosynostosis syndromes are diagnosed through physical examination at birth with CT scans and X-rays used to confirm the diagnosis. 

Genetic testing may be conducted for mutations of one of the fibroblast growth factor receptor (FGFR) genes.

Treatment

Syndromic craniosynostosis is more severe and requires more surgery than single suture synostosis. 

The choice and timing of surgery will depend on the type of syndromic craniosynostosis and the child’s age. 

Posterior Vault Expansion: There are three main types - Spring Cranioplasty, Posterior Vault Distraction, and Posterior Vault Expansion. 

Many children with syndromic craniosynostosis have bicoronal synostosis, resulting in a “short head” (brachycephaly) when viewed from the side. To improve the head shape and the give the brain room to grow, surgery is used to expand the volume at the back of the skull.

Fronto Facial Surgeries: There are three main types - Fronto Orbital Advancement (FOA), Le Fort III Distraction, Monobloc (Fronto Facial) Distraction.

Children with syndromic craniosynostosis can have unusual forehead shape, underdeveopled cheekbones, shallow orbits (causing prominent looking eyes), problems with the upper airway - causing snoring or Obstructive Sleep Apnoea (OSA), and a marked underbite. 

Surgery expands the volume at the front of the skull, repairing the above issues and respositioning the cheek bones when needed.  

Spring cranioplasty

Spring cranioplasty is a minimally invasive technique involving the placement of custom-made springs on the skull to gradually reshape and expand it. 

Surgery is usually performed around 6 months of age. The springs are removed at a second smaller procedure 3 months after the spring placement. 

Advantages

  • less invasive than traditional surgeries 
  • shorter hospital stays and quicker recovery times. 
  • safe and effective. 

Disadvantages

  • incomplete correction
  • need for a blood transfusion
  • infection of the springs
  • need for additional interventions as the child grows.  

Posterior vault distraction

Posterior vault distraction uses distractors to separate the skull bones, promoting natural bone growth. 

Cuts are made into the bone and the distractor device is applied. The distractor slowly moves the bone backwards via a screw until the desired result is achieved (this usually involves 2 or 3 screw turns a day for 2-3 weeks). 

After the bone is in its new position, the distractor device stays in place for 8 weeks before being removed via a second smaller procedure. Surgery can be performed at almost any age, but preference is around 9 – 12 months of age. 

Advantages

  • precise control over the expansion process 
  • can be adjusted during follow-up appointments
  • blood transfusions are usually avoided 
  • procedure is considered less invasive that the traditional Posterior Vault Expansion (see below). 

Disadvantages

  • requires intensive postoperative management in the days and weeks following surgery
  • risk of distractor infection and exposure
  • need for additional procedures as the child grows.  

Posterior vault expansion

A posterior vault expansion procedure without springs or distractors involves removing large amounts of bone at the back of the skull, reshaping and repositioning that bone and then closing the skin in one surgery. 

Advantages: 

  • correction in a single stage
  • useful in situations where 
    • a child is too old for spring cranioplasty
    • parents/carers are unable to turn the screw (distractor) arms for posterior vault distraction
    • there would be issues with having distractor arms protruding from the scalp 

Disadvantages

  • extensive surgical procedure with potential significant blood loss
  • damage to the dural lining of the brain and longer recovery times
  • amount of expansion that can be gained is less than that for either spring cranioplasty or posterior vault distraction. 

Fronto Orbital Advancement (FOA) surgery

FOA involves removing the forehead and orbit (the space within the skull that contains the eye) bones, reshaping them and then replacing them onto the skull using dissolving plates and screws. 

It is a routine but major craniofacial procedure. The surgery takes a few hours and is performed by plastic surgeons and neurosurgeons. Children remain in hospital for around 5 days afterwards. 

FOA is used to treat types of craniosynostosis of the front of the skull, where the forehead needs to be reshaped or repositioned, such as in the bicoronal craniosynostosis associated with syndromic craniosynostosis. It does not reposition the cheek bones. 

Advantages

  •  dramatic improvement in forehead shape and gives the brain room to grow
  • complication rate is low. 

Complications

  • risk of infection, bleeding
  • risk of damaging the dura (outside lining of the brain)
  • asymmetry, scarring
  • need for further surgeries to optimise the physical outcome when the child has finished growing. 

Le Fort III distraction surgery

Le Fort III distraction surgery is a major procedure that brings the cheek bones, nose and upper jaw forward in children who have underdevelopment in cheekbones, flat midface, small upper airway or prominent eyes. 

A frame is placed on the head which is connected to the facial bones via fine wires. The facial bones are slowly pulled forward by turning a screw on the back of the frame twice a day. 

The head frame is worn for 3 months and is removed in a small procedure when the bones have moved forward. 

Advantages 

  • controlled, gradual advancement of the cheekbones and upper jaws, improving the child’s profile
  • correcting the prominence of the eyes and expanding the upper airway. 

Disadvantages

  • bleeding
  • infection 
  • device breakage or displacement. 
  • the child has to wear the frame for a few months
  • success depends on patient and parental compliance with follow-up appointments and instructions. 

Monobloc (fronto facial) distraction surgery

In this surgery, the frontofacial (“monobloc”) of the forehead, upper orbital rim, cheekbones and upper jaws are slowly moved forward by turning the screw at the back of the frame twice a day to expand the space at the front of the brain, correct shallow eye sockets, expand the upper airway and improve the facial profile. 

Advantages

  •  corrects many of the structural issues associated with syndromic craniosynostosis in a single procedure – the brain, eye sockets and upper airway are all given more room
  • facial profile is improved
  • unlike traditional surgical approaches, Monobloc distraction surgery allows for slow advancement in a single procedure, reducing the risk of the bone retracting back (relapse) and providing greater control over the correction process. 

Disadvantages

  • risk of leakage of fluid from around the brain (CSF leak)
  • meningitis
  • bone infection and loss,
  • distraction device displacement
  • the child has to wear the frame for a few months
  • success depends on patient and parental compliance with follow-up appointments and instructions. 

 Management

Patients with syndromic craniosynostosis have more complicated needs than those with non-syndromic) craniosynostosis. Patients have impaired growth of the skull and facial bones that makes it harder to achieve a lasting correction of the appearance and maintain adequate space in the skull for the growing brain. 

A patient may need several operations during childhood to “catch up” to where they should be if their skulls and face were growing normally.

Patients with syndromic craniosynostosis frequently have additional problems with breathing, hearing, speech and eating. They may be born with deformed hands and feet which present additional functional and surgical challenges. 

Patients with complex problems require a team of specialists with expertise in each of the child’s problem areas and experience in caring for children with syndromic craniosynostosis.

Resources and more information

Healthdirect provides free, trusted health information and advice, 24 hours a day, 7 days a week online or via telephone 1800 022 022. 

Last updated Monday 6th May 2024

Disclaimer

This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024


This factsheet was produced with support from John Hunter Children's Hospital.