What is Craniosynostosis?

Definition:

• An infant's skull is made up of several free-floating bones connected by fibrous regions called sutures. These flexible connections allow the infant's head to pass through the birth canal and enable the skull to grow in response to the brain.
• Craniosynostosis refers to the early (premature) fusion of the sutures of the bones of the skull.  
• Craniosynostosis occurs in isolation (nonsyndromic) but is also present in many syndromes, such as Apert, Crouzon, Pfeiffer,Saethre-Chotzen, Carpenters and Opitz-C (also known as Opitz Trigonocephaly) syndrome.
• Craniosynostosis can be "simple" in which only a single suture is closed, or "complex" in which two or more sutures are closed. 

Effects:

• Premature fusing of the sutures restricts and distorts the growth of the skull. 
• These cranial growth restrictions often result in increased cranial pressure growth. This can potentially cause vision problems, eating difficulties, and impede intellectual development, resulting in a significant reduction in IQ.   
• The child's head takes on a distinct form which depends on the fused suture (or sutures):
• Premature fusion of the sagittal suture forces the skull to grow long relative to its width. This is predominately seen in males. (40-55% of cases)
• Premature fusion of the coronal sutures forces the skull to grow wide relative to its length (20-25% of cases)
• Premature fusion of the metopic suture (metopic craniosynostosis, also know as trigonocephaly) produces a narrow, triangular forehead with lateral pinching of the temples. (5-15% of cases)
• Premature fusion of one of the coronal or lambdoid (0-5% of cases) sutures results in asymmetrical head shape with flattening. 
• Premature fusion of both the coronal and sagittal sutures (oxycephaly) results in a an abnormally high conical head shape.
• Premature fusion of the coronal, lambdoid and posterior sagittal sutures [a rare condition] results in a cloverleaf skull (also known as kleeblattschadel).
• Abnormal head shape is associated with low self-esteem and behavioral problems.  Correction of these deformities can relieve cranial pressure and in the long-term, improve the child's self-esteem.

Causes:

• There are a number of genetic mutations that can cause syndromic craniosynostosis. When a gene mutates, the information it carries is mixed up, resulting in one of the bodily functions not working correctly.
• Research has not yet found a definite cause of nonsyndromic craniosynostosis, however there are a few theories. 
• The first is a possible cell defect in the sutures themselves that leads to them fusing too early. 
• A second theory is that when in the womb, the baby assumes an irregular position. If pressure was being put on the baby's head, the plates of bone in the skull might be pushed together and cause the sutures to fuse.

http://www.craniosynostosis.info/