Last revised by Mina Sameh Rizk on 4 Aug 2023

Craniosynostosis (plural: craniosynostoses) refers to the premature closure of the cranial sutures. The skull shape then undergoes characteristic changes depending on which suture(s) close early.

There is a 3:1 male predominance with an overall incidence of 1 in 2000-2500. 8% of cases are syndromic or familial.

Most occur as isolated anomalies but syndromic associations can be seen in a small proportion of cases (~10%):

Primary forms are either sporadic or familial. Secondary craniosynostosis occurs in relation to a variety of causes: 

The sagittal suture is most commonly involved (≈50%), where the lateral growth of the skull is arrested while anteroposterior growth continues, producing a narrowly elongated skull known as scaphocephaly (meaning boat-shaped) or dolichocephaly (from the ancient Greek for long, δολιχός: dolichos).

The next most common sutures in terms of involvement are:

  • coronal (~20%)

  • lambdoid (~5%)

  • metopic (~5%)

Restriction of skull growth is perpendicular to the affected suture line. Characteristic dysmorphic head shapes are associated with each type of craniosynostosis.

Ultrasound can be used as a screening tool or in clinically-subtle cases and can reduce radiation exposure in infants to cases with inconclusive findings 11.

General features include:

  • sutures are normally hypoechoic

    • there may be a loss of normally decreased echogenicity in the region of the fusion

  • lack of suture patency

  • ridging of the sutures

Low-dose CT with 3D image reformations is the best modality for the evaluation of skull sutures 5.

Treatment is often with a cranioplasty. Abnormal intracranial pressure may affect neurocognition.

Craniosynostosis was first accurately characterized by Rudolph Virchow in 1851 10.

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