Summary
Craniosynostosis refers to the premature fusion of one or more cranial sutures in newborns. The skull can then no longer grow symmetrically, leading to characteristic head shapes and, in severe cases, raised intracranial pressure and developmental delay. The only causal treatment is surgical – the earlier, the better. Surgery is performed in specialised interdisciplinary centres.
What is craniosynostosis?
Important distinction from positional plagiocephaly
In craniosynostosis one or more cranial sutures are fused – treatment is surgical. In positional plagiocephaly the sutures are open – treatment is conservative. This distinction is crucial.
Craniosynostosis is the premature closure of one or more cranial sutures. The rapidly growing infant skull bulges elsewhere – a characteristic deformity results and, in severe cases, raised intracranial pressure (ICP) with risk of brain damage and visual disturbance.
Frequency: about 1 : 2,500 live births. Second most common craniofacial malformation after cleft lip and palate. In 15–20 % of cases part of a genetic syndrome.
With a flat occiput and no suture ridge, positional plagiocephaly must first be considered → Positional plagiocephaly: causes and treatment
Which suture is affected? Six main forms
| Suture | Skull shape | Medical term | Share |
|---|---|---|---|
| Sagittal | Long, narrow, ridge front/back | Scaphocephaly / dolichocephaly | 40–55 % |
| Unilateral coronal | Asymmetric forehead, ear pulled back | Anterior plagiocephaly | 20–25 % |
| Metopic | Keel-shaped forehead, triangular head | Trigonocephaly | 10–15 % |
| Bilateral coronal | Short, broad, tower-like raised | Brachycephaly / turricephaly | approx. 5 % |
| Lambdoid | Flattened occiput, ear lower | Posterior plagiocephaly | 2–4 % |
| Multiple sutures | Variable, often turricephaly | Complex craniosynostosis | approx. 5 % |
Palpable suture ridge – leading sign
The most important clinical sign is a hardened, ridge-like bony elevation along the affected suture. This sign is absent in positional plagiocephaly.
Common associated syndromes with craniosynostosis
In 15–20 % of craniosynostoses a genetic syndrome is present. The following table shows a clinically meaningful selection of the most relevant syndromes – chosen by frequency and therapeutic importance for practice.
| Syndrome | Affected sutures | Characteristics | Gene(s) |
|---|---|---|---|
| Crouzon | Coronal, sagittal, lambdoid | Midface hypoplasia, exophthalmos – without syndactyly | FGFR2 |
| Apert | Coronal (bilateral) | Complex syndactyly of hands/feet, midface hypoplasia | FGFR2 |
| Pfeiffer | Coronal, sagittal | Broad thumbs/toes, 3 types (type 2/3 life-threatening) | FGFR1, FGFR2 |
| Saethre-Chotzen | Coronal (often unilateral) | Ptosis, ear anomalies, syndactyly II–III | TWIST1 |
| Muenke | Coronal | Most common syndromic CS; sensorineural hearing loss, variable penetrance | FGFR3 p.Pro250Arg |
Overarching presentation of craniofacial syndromes with embryology, genetic pathway and interdisciplinary treatment concept → kraniofazial.ch – Syndromes & treatment concepts
Diagnostics: clinical, imaging, genetics
Clinical diagnosis
- Palpable suture ridge – hardened bony ridge along the fused suture
- Characteristic skull shape according to the affected suture (see table above)
- In syndromic forms: midface underdevelopment, exophthalmos, sleep apnoea, visual disturbance
Imaging
- CT with 3D reconstruction: gold standard. Shows fused sutures, skull-bone morphology and orbit. Preferably under 6 months to minimise radiation exposure.
- MRI: assessment of the brain, exclusion of Chiari malformation (common in complex forms), ventricular width
- Ophthalmological examination: papilloedema as a sign of raised ICP – mandatory in all syndromic forms
- Polysomnography: sleep-apnoea screening in syndromic forms
Genetic work-up
In syndromic presentation or positive family history: panel testing (FGFR1/2/3, TWIST1, EFNB1, RAB23). Medical-genetics consultation recommended for family planning.
Surgical procedures: which – when – for whom?
| Procedure | Optimal age | Indication | Specifics |
|---|---|---|---|
| Endoscopic suturectomy | < 4–6 months | Simple, non-syndromic forms (sagittal, metopic) | Followed by helmet therapy 12–18 months; minimal blood loss |
| Open CVR (cranial vault remodeling) | 6–12 months | All syndromic forms; unilateral coronal suture | Complete remodeling of the cranial vault; higher blood loss |
| FOA (fronto-orbital advancement) | 6–12 months | Coronal and metopic suture synostoses | Forehead and orbit are advanced together |
| Spring-assisted craniotomy | 3–6 months | Sagittal suture synostosis | Implanted springs actively use growth; two-stage (insertion + removal) |
| Le Fort III distraction | 6–12 years | Syndromic midface hypoplasia (Crouzon, Apert, Pfeiffer) | Midface is distracted forward; external or internal distractors |
| Orthognathic surgery | From 16–18 years | Residual dysgnathia after growth completion | Bimaxillary osteotomy |
Le Fort III distraction, internal vs external systems, long-term results and adult care → Adults: osteotomy and midface distraction
ICP monitoring – why it is indispensable
Raised intracranial pressure can be asymptomatic in syndromic forms. Regular ophthalmological checks (papilloedema) and, where appropriate, ICP measurement are therefore part of the follow-up programme, not just initial work-up.
Specialised centres and professional societies
Interdisciplinary care
Syndromic craniosynostoses require a fixed interdisciplinary team. Many Swiss centres are associated with the European reference network ERN CRANIO (European Reference Network for Rare Craniofacial Anomalies and ENT Disorders) or follow its guidelines. Internationally, the ACPA (American Cleft Palate-Craniofacial Association) is also authoritative, having established worldwide standards for the multidisciplinary care of craniofacial patients.
Specialised centres in Switzerland:
- Kispi Zurich: neurosurgery, paediatric surgery, maxillofacial surgery, ophthalmology, speech therapy, orthodontics, ENT – largest interdisciplinary centre in Switzerland
- USZ Zurich: oral and maxillofacial surgery, orthognathic surgery
- CHUV Lausanne: paediatric neurosurgery, craniofacial surgery
- HUG Geneva: paediatric craniofacial surgery
- Inselspital Bern: neurosurgery, maxillofacial surgery
Funding: surgical treatment is generally covered by basic insurance (KVG); coverage is assessed case by case. In syndromic forms, disability insurance (IV) often covers additional services (rehabilitation, aids, speech therapy).
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