These gaps, known as cranial sutures, are designed to give the cranial bone plates flexibility, enabling the skull to grow along with the brain. In cases of craniosynostosis, one of these sutures closes before birth, or shortly after. This restricts the growth of the skull in one area, leading to overgrowth in another and resulting in an unusually shaped head.
Craniosynostosis is a rare defect that affects an estimated one in every 2,500-3,000 births, with boys three times more likely to develop the condition than girls. Craniosynostosis often develops alone without any other problems. However, in 4.5% of cases, craniosynostosis develops as part of a collection of birth defects, such as Apert's syndrome or Crouzon's syndrome (both of which are rare genetic conditions).
Craniosynostosis affecting the front of the head
When craniosynostosis affects the front part of the head, surgeons use a variety of frontal (forehead) remodelling or advancement procedures. Generally, this type of surgery is carried out at approximately 10-14 months, although this may vary if the condition is part of a more generalised syndrome. Surgeons have found that if these operations are carried out before the age of ten months, patients tend to grow out of them, meaning that further operations may be needed at a later date.
Operations to treat frontal craniosynostosis usually involve moving and reshaping not only the forehead but also the upper part of the eye sockets. In most cases, the bone of the forehead is removed completely from the skull and reshaped into a more normal form. The upper part of the eye sockets are then released from their attachments, shaped into a more normal configuration, and fixed into their new position using either fine wires or, occasionally, small plates and screws. The bone of the forehead is then reattached to the upper part of the eye sockets, again with wires, plates or screws. A small gap is usually left to allow for further growth as the brain expands.
What surgery is available, and what techniques are involved?
Surgical treatment of craniosynostosis varies depending on the age at which a patient is first seen. If a child is very young, i.e. up to six months, the bones of the skull are still relatively soft and pliable, and surgeons can bend or mould these bones into a more normal shape.
In such cases, the bones are usually repositioned using absorbable sutures. These sutures take some time to dissolve and will remain in place until the bones have set and healed in their new position.
When treatment is carried out on children over the age of six months, the surgery becomes more complex. After this time it is no longer possible to mould the bones of the skull, as they will have become much more brittle. It is therefore necessary to remove a large area of bone in order to reshape it, or to reposition it so that the overall shape of the skull can be normalised. Exact treatment requirements will vary from patient to patient, but in general this is a relatively major operation. Surgeons fasten the cranial bones in their new position using wire sutures, which remain in place and are not removed unless they start to cause problems.
What should I expect as a patient/parent of a patient?
For younger children, the operation to correct craniosynostosis is a lesser procedure compared with most other craniofacial interventions, and a child will usually be in hospital for four to five days.
For older children, it can occasionally be difficult to stabilise the bones in their new position with wires, in which case small metal plates and screws will be used. Patients will usually be in hospital for seven to ten days.