Craniosynostosis refers to 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.
Primary forms are either sporadic or familial. Secondary craniosynostosis occurs in relation to a variety of causes:
- endocrine disorders
- vitamin D deficiency
- haematological disorders causing bone marrow hyperplasia
- sickle cell
- inadequate brain growth
- shunted hydrocephalus
- brachycephaly: bicoronal and/or bilamboid sutures
- scaphocephaly/dolichocephaly: sagittal suture
- plagiocephaly: unilateral coronal and lambdoid sutures
- trigonocephaly: metopic suture
- pachycephaly: lamdoid suture
- oxycephaly/turricephaly: sagittal, coronal and lambdoid sutures (Tower like skull)
- cloverleaf skull/Kleeblattschadel: intrauterine sagittal, coronal, lambdoid sutures (most severe)
- harlequin eye: ipsilateral coronal suture
The sagittal suture is most commonly involved (≈50%), where lateral growth of the skull is arrested while anteroposterior growth continues, producing a narrow 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%)
Most occur as isolated anomalies but syndromic associations can be seen a small proportion of cases (~10%):
- acrocephalosyndactyly/acrocephalopolysyndactly types
- choanal atresia
CT with 3D image reformations is the best modality used for evaluation of sutures 5.
Treatment and prognosis
Treatment is often with a cranioplasty.
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