Craniosynostosis

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

Examples 

• brachycephaly : bicoronal and/or bilamboid sutures
• scaphocephaly / dolichocephaly : sagittal suture 
• plagiocephaly : unilateral coronal and lambdoid sutures
  • frontal plagiocephaly : unilateral coronal suture
  • occipital plagiocephaly : unilateral lambdoid suture 
• 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. 

The next commonest sutures in terms of involvement are 

• coronal : ~ 20%
• lambdoid : ~ 5 %
• metopic : ~ 5 %

Pathology

Causes are primary, or secondary to certain haematologic disorders, metabolic disorders, bone dysplasias and syndromes. There is a 3:1 male predominance. 

Associations

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

• acrocephalosyndactyly / acrocephalopolysyndactly types
  • Apert syndrome
  • Carpenter syndrome
  • Crouzon syndrome
• choanal atresia

Treatment

Treatment is often with a cranioplasty.