Craniosynostosis is a premature fusion of the bones that make up the skull. The skull is made up of several bones with gaps between the bones called sutures or bony joints. These sutures are the connections between the bones and are the growth centers of the skull. It is easier to understand as the bones grow from the edges rather than the center of the bones.
When these edges of the bone at the sutures fuse together, then the two bones become one bone and can only continue to grow at the edges. This restricts skull growth in certain three dimensional directions and causes an abnormal head shape with distortion of facial features. Sometimes this can also cause increased intracranial pressure which can lead to brain damage or blindness.
Typically only one suture is affected and this is known as Single Suture Craniosynostosis. This is usually not an inherited genetic condition but a spontaneous occurrence. When more than one suture is involved then we consider this a Multiple Suture Craniosynostosis which has a higher chance of having a genetic cause. This is more frequently seen in Syndromic Craniosynostosis such as Apert Syndrome, Pfeiffer Syndrome, or Crouzon Syndrome. With these conditions a geneticist is involved to help guide you through what to expect and determine the cause.
The team involved with treating craniosynostosis are:
- Craniofacial Plastic Surgeon
- Pediatric Neurosurgeon
- Pediatric Ophthalmologist
- Pediatric Anesthesiologist
- Pediatric Intensive Care Specialist
For more information please visit the following pages:
- Sagittal Craniosynostosis
- Metopic Craniosynostosis
- Coronal Craniosynostosis
- Lambdoid Craniosynostosis
Frequently Asked Questions
What is Craniosynostosis?
Craniosynostosis is the premature closing or fusion of cranial sutures (bony joints) between different bones that together make up the skull.
When does craniosynostosis occur?
Craniosynostosis occurs while a child is developing in the womb.
How often does single suture craniosynostosis occur?
The incidence of single suture craniosynostosis is around 1 in every 2,000 babies born.
What causes craniosynostosis?
To date, there has not been one specific cause identified. Some animal studies done suggest intrauterine constraint may lead to premature cranial suture (bony joint) closure. That means if the child becomes stuck in a certain position in the womb this could constrain the childs head preventing growth and lead to premature suture closure. It has also been suggested that the incidence of single suture closure is higher in boys because of the male sex hormone testosterone. The theory is testosterone increases the “stickiness” of cranial sutures which encourages them to close prematurely.
How do I know if my child has craniosynostosis?
Evaluation of your child’s head shape is predictive of craniosynostosis in 99% of cases. If one of the sutures (skull joints) fuses closed, the other sutures (joints) try to compensate for the loss of growth in this one area. The other sutures compensation lead to a three dimensional head shape consistent with a particular suture fusion. As your child grows, this head shape becomes more characteristic of craniosynostosis. Your child would need to be examined by a craniofacial surgeon to help confirm the diagnosis.
Does my child need a CT (CAT) scan to confirm the diagnosis of craniosynostosis?
Typically a CT scan of the head is not always necessary. As mentioned above, the diagnosis is usually determined on physical exam alone. A CT scan is helpful if more than a single suture is suspected to be fused. This will help in the planning surgical reconstruction of the skull. An MRI is useful if Arnold Chiari Malformation (brain herniation at the base of the skull to the spinal cord) is suspected.