Plagiocephaly

A flattening on one side of the back of the head.

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Plagiocephaly is becoming increasingly more common due to widespread efforts to reduce the incidence of Sudden Infant Death Syndrome (SIDS) by encouraging parents to place their babies on their backs to sleep instead of on their bellies. In fact, up to 46% of otherwise healthy babies are estimated to experience an asymmetrical head shape.1

Causes of Plagiocephaly

At birth, the bones in your baby’s head are soft, allowing their brain to grow and develop. When this growth is restricted, it limits the expansion of the skull, causing a flat or asymmetrical head shape to occur. It generally happens when your baby’s head is pressed in one position for an extended period of time, either during pregnancy or after birth.

Some of the risk factors that may restrict the natural growth of your baby’s skull include:

  • Premature birth
  • Congenital muscular torticollis (a tilting and/or turning of a baby’s neck to one side as a result of a muscle strain)
  • Multiple births (twins, triplets, etc.)
  • Restrictive positioning during pregnancy
  • Trauma at birth
  • Cervical spine abnormalities
  • Favoring one side over another

Plagiocephaly: Three Common Head Shapes

An asymmetrical head shape is often noticed in babies older than six weeks of age by their pediatrician, physical therapist, parents, or family members, and can range in location, presentation, and severity. 

Plagiocephaly, or “flat head syndrome,” is the most common form of cranial asymmetry and is usually identified by a flattening on one side of the back of the head.​ It is sometimes referred to as a parallelogram shape, because it looks like one side of the baby’s head has been pushed forward.


Brachycephaly generally appears as flattening across the back of the head with a prominent forehead, widening above the ears, and the height of the baby’s head may appear taller.


Scaphocephaly is typically observed as a long, narrow head shape. It is commonly seen in premature babies who spent time in the NICU or consistently rest on either side of the head.

How to Identify an Asymmetrical Head Shape

While no child (or adult) has a perfectly symmetrical head, there are ranges of normal development. The majority of cranial asymmetries will correct on their own during the first weeks of life. However, a head shape that is not getting better, or may be getting worse, should be evaluated.

One of the best ways to look for asymmetry is to look at your baby’s head from above (the bird’s eye view) while his or her hair is wet.​ Also look for red creases on one side of your baby’s neck as they may result from his or her head being cocked to one side, which may be a sign of torticollis.

If you notice any irregularities, schedule an appointment with your child’s pediatrician or physical therapist and ask for a referral to Hanger Clinic for a free evaluation. Whether your baby needs some extra tummy time, repositioning, or helmet therapy, there is a lot that can be done to correct the asymmetry.

Our care at Hanger Clinic has been exceptional. The team worked with two of my daughters and held our hand throughout the entire process. I can’t say enough good things about them!

Natalie A., Mom to Hanger Clinic Patient Colette

Steps to Getting a Cranial Helmet

A cranial remolding orthosis, also known as a cranial helmet or cranial band, is a proven treatment designed to help the flattened areas of your baby’s head to grow, forming a rounder, more symmetrical shape.

If you have been referred to Hanger Clinic for a cranial helmet, here is what you can expect:

We provide free cranial evaluations to help ensure you are educated and informed prior to making the decision on whether to move forward with your baby’s treatment. If your baby is very young (under 4 months) or has been diagnosed with mild-to-moderate asymmetry, we encourage you to work with your baby’s physician or physical therapist on repositioning techniques first, prior to treatment.

Once treatment is determined to be necessary and you have a prescription from your baby’s physician, our clinical team will advise on the length of care (generally 3 – 6 months) and will begin the process of fabricating a custom cranial helmet using modern digital scanning technologies.

Your baby’s scan will be sent to a design center, where it will be modified based upon your baby’s head shape and anticipated cranial growth. The cranial helmet is then fabricated using a multi-step process in accordance with FDA guidelines.

Within 14 days of the scan, your family will return to our clinic for fit and delivery. At that time, the orthotist will evaluate and refine the fitting of the cranial band and review the break-in schedule and cleaning instructions with your family. They will then schedule the necessary follow-up appointments.

Follow-up appointments are usually scheduled every 2-4 weeks and typically include mid-treatment and end-of-treatment scans, so you can see progress in an easy-to-read report that can be shared with other healthcare providers.

When your baby graduates out of their cranial helmet, we will celebrate his or her success!


1. Mawji A, Vollman AR, Hatfield J, McNeil DA, Sauvé R. The incidence of positional plagiocephaly: a cohort study. Pediatrics. 2013 Aug;132(2):298-304. doi: 10.1542/peds.2012-3438. Epub 2013 Jul 8. PMID: 23837184.

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