Summary
Positional plagiocephaly is a positioning-related flattening of the back of an infant's head, with open cranial sutures. The head becomes asymmetric due to one-sided lying pressure – the brain is not affected. Treatment is always conservative: physiotherapy, positioning correction, possibly a helmet orthosis. Surgery is never required. It must be distinguished from craniosynostosis, in which a suture is fused and must be operated on.
What is positional plagiocephaly?
Not a craniosynostosis
Positional plagiocephaly results from pressure on the soft skull – the sutures are open, the brain develops normally. No surgery is needed. The distinction from craniosynostosis, in which a suture is fused, is decisive.
Since the "Back to Sleep" recommendation for SIDS prevention (1992), the frequency has increased markedly. Today 15–20 % of all infants are affected – making positional plagiocephaly the most common skull-shape change in infancy.
Brachycephaly (symmetric flattening of both sides of the occiput) arises from the same mechanisms and is treated the same way.
If a hardened suture ridge or a rapidly progressive skull asymmetry is present, craniosynostosis must be ruled out → Craniosynostosis: types and treatment
Positional plagiocephaly vs craniosynostosis: at a glance
| Feature | Positional plagiocephaly | Craniosynostosis |
|---|---|---|
| Sutures | Open, palpable | Closed, fused |
| Ear displacement | Ear displaced ipsilaterally forward | Ear ipsilaterally backward or normal |
| Forehead | Prominent ipsilaterally (compensatory) | Deformed depending on the suture |
| Suture ridge | No | Yes (palpable) |
| Onset | Postnatal, weeks 1–3 | Prenatal or at birth |
| Treatment | Conservative (positioning, PT, helmet) | Surgical |
Clinical rule of thumb
In positional plagiocephaly the ear on the flat side is displaced forward – as if, viewing the head from above, you saw the ear "slide" toward the tip of the nose. In craniosynostosis this sign is absent.
Why does positional plagiocephaly develop?
A newborn's skull is not yet fully ossified – sustained pressure on the same spot changes its shape. The following factors increase the risk:
- Preferred head position during sleep – most common cause; the child preferentially turns the head to one side
- Muscular torticollis – shortening of the sternocleidomastoid muscle; involved in 10–30 %; often combined
- Tight intrauterine space – multiple pregnancy, large baby, oligohydramnios
- Prematurity – even softer skull, longer lying times in intensive care
- Time spent out of bed – car seat, baby carrier seat, bouncer, swing – accumulate daily
- Male sex – slightly increased risk
Cranial Vault Asymmetry Index (CVAI)
The diagnosis is made clinically: inspection from above (bird's-eye view) and calliper measurement of the skull diagonals. A CT is indicated only when craniosynostosis is suspected.
| Severity | CVAI | Recommended measure | Time window |
|---|---|---|---|
| Mild | < 3.5 % | Parental counselling, positioning optimisation, tummy time | From diagnosis |
| Moderate | 3.5–6.25 % | Physiotherapy, possibly helmet from 4–6 months | Start immediately |
| Severe | > 6.25 % | Helmet strongly recommended | Do not delay |
CVAI = difference of the skull diagonals / larger diagonal × 100. Values above 3.5 % are considered treatment-relevant.
Three-stage concept: positioning → physiotherapy → helmet
Stage 1 — Positioning therapy (immediate, always)
- Tummy time: at least 30–60 min/day under supervision, split into several short sessions. Strengthens neck and shoulder muscles, relieves the occiput. Begin from the first week of life.
- Sleep position: change the changing table, mobile and light source daily so the child does not always turn the head to the same side.
- Minimise lying times: limit car seat and bouncer to what is necessary – no sleeping in the car seat outside the vehicle.
- Carrying: a sling or carrier relieves the occiput and at the same time promotes motor development and bonding.
Stage 2 — Physiotherapy (in case of torticollis)
If muscular torticollis is present, physiotherapy with manual stretching and active exercises is the treatment of choice. Parents learn the exercises and perform them daily. In Switzerland generally covered by basic insurance (KVG) – a medical prescription is required.
Stage 3 — Helmet therapy (cranial remoulding orthosis)
Optimal time window
The helmet works by specifically guiding the natural growth of the skull. Optimal age: 4–6 months. The effect decreases with increasing age; from 12–14 months there is hardly any correction potential left.
| Aspect | Details |
|---|---|
| Wearing time | 23 h/day, 3–6 months |
| Established systems | Cranial Technologies DOC Band, STARband, custom-made orthosis |
| Mode of action | Gives the flattened side room; slows the prominent side – uses the infant's rapid skull growth |
| Costs in Switzerland | Approx. CHF 2,500–4,000 – usually not covered by KVG; disability-insurance contribution only in exceptional cases (e.g. severe underlying disease) |
| Evidence | RCT (van Wijk et al. 2014): helmet and active exercises comparable in mild cases; in severe CVAI, helmet therapy shows better long-term results |
Who treats – and who pays?
The initial assessment is done by the paediatrician. The main care pathways:
- Suspected torticollis: referral to paediatric physiotherapy – generally covered by KVG
- CVAI 3.5–6.25 %: conservative measures + follow-up check after 6–8 weeks
- CVAI > 6.25 % or no response: referral to a specialised centre for helmet-therapy assessment
- Suspected craniosynostosis: referral to a neurosurgical or paediatric surgical centre; 3D CT
Specialised centres in Switzerland: Kispi Zurich, CHUV Lausanne, Inselspital Bern, UKBB Basel, KSSG St. Gallen.
Helmet providers: specialised orthopaedic companies and helmet providers in all major conurbations. Ask your centre for local recommendations.
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