craniosynostosis

Craniosynostosis is a condition in which one or more of the cranial sutures fuse prematurely, restricting skull growth and sometimes altering head shape. It can occur in isolation (nonsyndromic) or as part of a genetic syndrome (syndromic). The most commonly affected sutures are the sagittal, coronal, metopic, and lambdoid sutures.

Nonsyndromic craniosynostosis affects about 1 in 2,000 to 2,500 live births. Syndromic forms are rarer and linked to genetic mutations in FGFR2, FGFR3, TWIST1, EFNB1, and related genes. Inheritance ranges from familial autosomal dominant to de novo mutations with variable expressivity.

Clinical features depend on the fused suture. Sagittal fusion typically causes scaphocephaly, a long narrow skull. Coronal fusion may produce anterior plagiocephaly and facial asymmetry. Metopic fusion leads to trigonocephaly with a triangular forehead. Lambdoid fusion causes posterior plagiocephaly and skull distortion. When multiple sutures fuse, there is a greater risk of increased intracranial pressure and impaired brain growth.

Diagnosis usually begins with physical examination and is confirmed by imaging. Computed tomography with three-dimensional reconstruction is commonly used to delineate fused sutures and plan treatment; ultrasound can screen very young infants. Differentiation from deformational plagiocephaly is essential, as that condition does not involve suture fusion.

Management depends on severity and age. Mild nonsyndromic cases may be observed. Surgical options include endoscopic-assisted suturectomy with postoperative molding helmets for select infants younger than about six months, and open cranial vault remodeling or fronto-orbital advancement for more complex or older cases. Multidisciplinary care is recommended.

Prognosis is generally favorable with timely treatment. Long-term follow-up focuses on craniofacial growth, neurodevelopment, and the potential need for secondary procedures or surveillance for raised intracranial pressure in complex cases.