what is craniosynostosis
In contrast to normal skull growth, in which the skull expands uniformly to accommodate the growth of the brain, premature closure of a single suture restricts the growth in that part of the skull and promotes growth in other parts of the skull where sutures remain open. This results in an abnormal shape of the skull, but does not prevent the brain from expanding to a normal volume.
Sometimes, many sutures close prematurely, and the skull cannot expand to accommodate the growing brain, which leads to increased pressure within the skull and impaired development of the brain. Craniosynostosis can be gene-linked, or caused by metabolic diseases, such as rickets or an overactive thyroid. Some cases are associated with other disorders such as microcephaly (abnormally small head) and hydrocephalus (excessive accumulation of cerebrospinal fluid in the brain).