Lambdoid craniosynostosis is an uncommon condition, with an incidence of 1 per 33,000 live births. The lambdoid suture extends across the back of the head. Each parietal bone plate meets the occipital bone plate at the lambdoid suture.
Sutures allow the bones to move during the birth process. They act like an expansion joint, allowing the bone to enlarge evenly as the brain grows and the skull expands, resulting in a symmetrically shaped head. However, if any of the sutures close too early (fuse prematurely), there may be no growth in that area. This may force growth to occur in another area or direction, resulting in an abnormal head shape.