An approach to the infant with plagiocephaly

A 4-month-old boy presents to the paediatric ED. His parents are concerned about the appearance and shape of his head.

They ask how this can be fixed.

Before we get into the clinical case, let’s consider some anatomy and background.

Sutures and skull development in infancy

The skull is made up of five bones – two frontal bones, two parietal bones and an occipital bone. Each bone sits adjacent to its neighbour. Sutures, the junction between the bones, allow the bones to move during birth and allow the skull to expand as the brain grows.

Terminology

Plagios is ancient Greek for oblique or slanting 

Cephal is Latin for head or skull. 

When put together as ‘plagiocephaly’, the term broadly means cranial asymmetry. 

Deformational plagiocephaly is due to external forces causing constraint or twisting. Possible causes include twin pregnancy, intra-uterine constraint, or sleeping position. 

Positional plagiocephaly is a form of deformational plagiocephaly, specifically referring to plagiocephaly secondary to external forces against one side of the head from lying flat. 

Craniosynostosis refers to the premature fusion of one or more cranial sutures. 

The distinction between plagiocephaly and craniosynostosis is important as the level of concern and management are different.

What causes plagiocephaly?

The ‘Back to Sleep’ Campaign in 1991 reduced sudden infant death by up to a half. The parallel effect, however, was an increase in babies with plagiocephaly. Although there is little good-quality prospective evidence confirming potential risk factors, there is an epidemiological correlation to support the theory that cumulative time spent sleeping supine correlates with positional plagiocephaly. 

Our job is to differentiate between the self-limiting benign condition of positional plagiocephaly and undiagnosed craniosynostosis.

An approach to a child with plagiocephaly

Start by taking a full perinatal history, including complications during pregnancy, twin or triplet pregnancy, and delivery, including any instrumentation. 

Explore when the carers first noticed the head shape. Was it at birth or more recently? 

Ask about the sleeping position. 

Take a developmental history. Are milestones being met? 

Take a systems review and ask about any other parental concerns.

Next, examine the infant’s head.

Look

Examine the head from the top (vertex view).

In positional plagiocephaly, the skull has a characteristic parallelogram shape with unilateral occipital flattening and ipsilateral frontal bossing.

Look for any difference in the position of the orbits. A difference in orbit position suggests something else – premature suture fusion, i.e. craniosynostosis. 

Feel

Palpate the fontanelles and sutures. Can you feel any fused/ rigid suture lines? 

Measure

Measure head circumference. NICE recommends measuring the distance between the outer canthus of the baby’s eye and the tragus of the ear on each side.

If these measurements are not the same, the baby has plagiocephaly, and if they are developing normally, you don’t need to refer.

If the measurements are the same, however, suspect unilateral premature closure of the lamboid sutures and refer to your local services.

Craniosynostosis

Craniosynostosis is rare. It is due to the premature closure of the sutures rather than positional changes to an otherwise normal skull. There are many causes, and it is less well understood than plagiocephaly.

Craniofacial syndromes, such as Alpert, Crouzon and Pfeiffer, associated with mutations of the fibroblast growth factor receptor pathway, account for a minority of cases. Most are idiopathic with no clear genetic cause. 

Craniosynostosis can lead to raised intracranial pressure and failure to thrive. and can worsen and become harder to correct over time. This can lead to intracranial hypertension and neurodevelopmental delay. 

Craniosynostosis needs urgent referral and is usually corrected operatively before a child’s first birthday. 

Features of craniosynostosis include: 

– Abnormal head shape noted at or shortly after birth 
– No palpable fontanelle 
– Raised firm sutures 
– Delayed head growth over time 
– Appearance of baby face suggesting craniofacial syndromes

In unilateral lambdoid craniosynostosis, the head shape resembles a trapezium because one side of the head is restricted in growth. Craniosyntosis can be anterior due to unicoronal suture closure or posterior due to lambdoid suture closure.

You take a thorough history and are happy that the baby is meeting its developmental milestones. The head shape appeared normal at birth, and the flattening was noticed only recently.

The baby sleeps in a bedside cot, on his back for all naps and at night. Examination reveals an obvious flattening across the back of the baby’s head.

There is no difference in orbital position, and the head is parallelogram-shaped. The fontanelles were normal, and there were no palpable fused suture lines.

A top-to-toe examination reveals normal neurology and no syndromic features. 

You suspect this is a case of ‘Positional Plagiocephaly’.

What should we tell parents?

Positional plagiocephaly is a common, benign condition. The ‘natural’ shape of the head is normal and it should re-mould without surgery or intervention. 

Position changes can help, so when they are awake, encourage tummy time. When the child is lying awake and lying on their back, use distraction, hanging mobiles, and toys to encourage head movement away from the effected side. 

Consider using a sling to carry rather than prolonged periods of lying flat in a pram. 

Reiterate safe sleeping guidelines. Even in babies with positional plagiocephaly, the advice is always to put the baby to sleep on the back as this can reduce the risk of sudden infant death. Never put toys, pillows, or props in the cot with a sleeping baby. 

What about helmet therapy?

The Academy of Medical Royal Colleges and NICE guidance does not advocate the use of helmet therapy.

They risk pain and pressure sores. They can also affect baby-caregiver bonding and are an added expense with no proven benefit.

What is the prognosis?

Positional plagiocephaly is a benign, self-limiting condition. It resolves when the child becomes more mobile and becomes less obvious as hair grows and covers the skull.

Bottom Line

Babies under one with unilateral head flattening, a parallelogram shaped head, and no other concerning features in history or examination can be safely diagnosed with positional plagiocephaly. 

Positional plagiocephaly is benign and can be managed conservatively. 


Craniosynostosis is the premature fusion of one or more of the cranial sutures and requires onward referral to specialists. 

Features suggestive of craniosynostosis include abnormal head shape noted at or shortly after birth, abnormal fontanelle, palpable fused suture lines, delayed head growth or concerns regarding generalised neurology of failure to meet developmental milestones. 

Get a second opinion if you are unsure.

References

The ISPN Guide to Pediatric Neurosurgery (USA): Positional Plagiocephaly in Children Homepage. New York, USA: The International Society for Pediatric Neurosurgery, 2024 (Accessed January 9, 2024).

Bialocerkowski, A. E., Vladusic, S. L., & Wei Ng, C. (2008). Prevalence, risk factors, and natural history of positional plagiocephaly: a systematic review. Developmental Medicine & Child Neurology, 50(8), 577–586. https://doi.org/10.1111/j.1469-8749.2008.03029.x 

Bomer-Skogstad J, Dremmen M, Mathijssen I, Smithuis R. Craniosynostosis, The Radiology Assistant. The Radiology Assistant: Craniosynostosis Accessed 10.01.2024 

Mawji, A., Vollman, A. R., Hatfield, J., McNeil, D. A., & Sauvé, R. (2013). The Incidence of Positional Plagiocephaly: A Cohort Study. Pediatrics, 132(2), 298–304. https://doi.org/10.1542/peds.2012-3438 

Mitchell, E. A. (2006). Recommendations for sudden infant death syndrome prevention: a discussion document. Archives of Disease in Childhood, 92(2), 155–159. https://doi.org/10.1136/adc.2005.076752 

National Institute for Health and Care Excellence (Great Britain), National Guideline Centre (Great Britain), & Royal College of Physicians of London. (n.d.). Suspected neurological conditions : recognition and referral. 

Purnell, C. A., Benz, A. W., & Gosain, A. K. (2015). Assessment of Head Shape by Craniofacial Teams. Journal of Craniofacial Surgery, 26(6), 1808–1811. https://doi.org/10.1097/SCS.0000000000001948 

Santiago, G. S., Santiago, C. N., Chwa, E. S., & Purnell, C. A. (2023). Positional Plagiocephaly and Craniosynostosis. Pediatric Annals, 52(1), e10–e17. https://doi.org/10.3928/19382359-20221114-03 

van Wijk, R. M., van Vlimmeren, L. A., Groothuis-Oudshoorn, C. G. M., van der Ploeg, C. P. B., IJzerman, M. J., & Boere-Boonekamp, M. M. (2014). Helmet therapy in infants with positional skull deformation: randomised controlled trial. BMJ, 348(may01 8), g2741–g2741. https://doi.org/10.1136/bmj.g2741 

Wilbrand, J.-F., Wilbrand, M., Malik, C. Y., Howaldt, H.-P., Streckbein, P., Schaaf, H., & Kerkmann, H. (2012). Complications in helmet therapy. Journal of Cranio-Maxillofacial Surgery, 40(4), 341–346. https://doi.org/10.1016/j.jcms.2011.05.007