Craniosynostosis and Craniofacial Disorders
Craniosynostosis is a congenital deformity of the infant skull that results when the skull sutures (fibrous joints) between various skull bones fuse improperly. Skull growth is limited at the fused suture, and growth at the remaining sutures results in an abnormal shape to the infant skull. Craniosynostosis is usually apparent in infancy and is characterized by an abnormal but characteristic head shape, depending upon how many, and which, sutures are involved. In most cases, the problem is solely cosmetic and leads to an abnormal head shape; sometimes, the growth of the facial bones is affected as well. Rarely is the growth of the skull restricted enough to cause increased pressure in the head and lead to headaches, visual loss, or developmental delays.
The severity of the deformity depends on which sutures close, the point in the development process that the closure occurred, and the success or failure of the other sutures to compensate by expansion.
The majority of cases of craniosynostosis are sporadic and there is no family history or other causal factor. In some instances, craniosynostosis is inherited and can be associated with other developmental problems.
The diagnosis is usually apparent simply by examining the child’s head. A radiological examination is usually necessary both to confirm the problem, characterize the deformity, and guide the corrective surgical procedure. Plain x-rays of the skull usually show the problem well; computerized tomography scans provide additional information about the fused sutures and the status of the underlying brain. Three-dimensional (3-D) computed tomographic scans may provide information to guide surgical correction.
Surgery involves releasing the fused suture and correcting the cosmetic deformity. A number of different procedures are available to correct the deformity. When multiple sutures are fused and the pressure in the head is raised, surgery may be necessary to relieve intracranial pressure and accommodate for brain growth, as well as improve cosmetic appearance.
One of the most common reasons for a malformed head shape is occipital flattening (or plagiocephaly), a condition which is frequently confused with lambdoid craniosynostosis (fusion of the lambdoid suture in the back of the head). In occipital flattening, the infant’s head is flattened in the back (the occiput) because the infant lies persistently on the back of the head (often with the head turned preferentially to one side). In addition, the ear on that side is often pushed forward, and even the forehead may seem a bit prominent compared with the other side. This produces a parallelogram shape to the infant’s head. X-rays can show a small amount of bone build-up which is misinterpreted as fusion of the lambdoid suture; however, occipital plagiocephaly is not caused by lambdoid craniosynostosis and usually does not need to be treated surgically.
Copyright© 1998-2003; American Association of Neurological Surgeons / Congress of Neurological Surgeons
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