Plagiocephaly
Etymology: Plagiocephaly is derived from Greek, literally meaning “oblique head.”
It describes an asymmetrical or flattened skull shape that develops due to external pressure on an infant’s head.
Aetiology and Risk Factors
Deformational plagiocephaly arises when repeated external forces on the malleable infant skull result in flattening. Key risk factors include:
- Supine sleeping position
Infants who sleep predominantly on their backs or spend extended periods in car seats, prams, or bouncers without head position changes are at increased risk. - Congenital muscular torticollis
Tightening or shortening of one or more sternocleidomastoid muscles leads to a consistent head tilt or preference for turning in one direction, contributing to unilateral pressure. - Prematurity
The cranial bones of premature infants are especially soft and pliable, making them more vulnerable to deformity from external forces. - Intrauterine constraint
Less commonly, plagiocephaly may be present at birth due to restricted fetal movement or “crowding,” such as:- Multiple gestation
- Breech presentation
- Small maternal pelvis or uterine anomalies
Diagnosis and Differential
- Clinical diagnosis is based on head shape and positional history.
- Important differential: Craniosynostosis
This condition involves premature fusion of cranial sutures and may also cause asymmetry. However, unlike deformational plagiocephaly, there is no suture fusion in positional cases.
Facial asymmetry is typically more pronounced in craniosynostosis and may require neurosurgical assessment.
Management
1. Observation and Natural Improvement
- Mild cases often improve spontaneously once the infant begins independent sitting and mobility.
- Monitoring head shape progression is recommended during routine developmental checks.
2. Early Physiotherapy for Torticollis
- Early identification and referral for physiotherapy is crucial where torticollis is present.
- Stretching and strengthening exercises improve neck range of motion and head positioning.
3. Counter-Positioning (Repositioning Therapy)
- Most effective when initiated before 4 months of age.
- Techniques include:
- Alternating head position during sleep.
- Encouraging tummy time during waking hours.
- Side-lying supervised play.
- Use of supportive towel rolls or positioning devices (under guidance).
- Instruction is typically provided by maternal and child health nurses or paediatric physiotherapists.
4. Helmet Therapy (Cranial Orthosis)
- Considered in moderate to severe cases or when conservative repositioning has failed.
- Most effective between 4–8 months of age, coinciding with rapid skull growth.
- Helmets:
- Are custom-fitted by a qualified orthotist.
- Consist of a lightweight hard shell with a foam lining.
- Typically worn 23 hours/day for 2–6 months, depending on age and severity.
- Function by offloading pressure on flattened areas to promote symmetrical cranial growth.
Summary Table
| Aspect | Deformational Plagiocephaly | Craniosynostosis |
|---|---|---|
| Cause | External pressure | Premature fusion of cranial sutures |
| Suture fusion | Absent | Present |
| Onset | Often postnatal | Can be congenital or develop early |
| Skull shape | Asymmetrical, often occipital flattening | Asymmetry with palpable ridging |
| Facial asymmetry | Mild or absent | Often marked |
| Treatment | Conservative ± Helmet | Surgical referral may be required |
