In craniosynostosis syndromes, one or more bones of the skull and face fuse prematurely during fetal development. The skull is composed of multiple bones separated by sutures, or openings. If any of these close too early, the skull will expand in the direction of the open sutures, resulting in an abnormal head shape.
Premature closure of a single suture can be caused by space constraints in the womb, and is seen more often in twins than in a single fetus. Single suture closure usually isn't associated with a syndrome. Premature closure of multiple sutures, however, is often seen in children with a craniosynostosis syndrome.
In children with a craniosynostosis syndrome, bones that fuse prematurely in the skull result in abnormal head shapes. Bones in the face may also be fused together, resulting in a flat midface and protruding eyes.
The most common craniosynostosis syndromes are Crouzon, Pfeiffer and Apert.
Children with Apert, Crouzon and Pfeiffer syndrome usually have premature fusion of at least the coronal suture, an opening that extends across the top of the skull. Other sutures may also close.
A baby with single suture synostosis that's not part of a syndrome usually doesn't have any functional problems, such as difficulty breathing or feeding. Surgical release of the closed suture may be necessary, and if so, would usually be done during the first year of life.
An infant with a craniosynostosis syndrome should be seen immediately after birth by a nurse from the Center for Craniofacial Anomalies to make sure the infant can adequately breathe and feed. Shortly after being discharged from the hospital, the child should be seen for a full team evaluation at the center. The skull abnormalities require early attention, although the timing varies. A surgical procedure to advance the forehead is usually done before the baby is 6 months old.
Reviewed by health care specialists at UCSF Benioff Children's Hospital.