Cranial Technologies

What is Plagiocephaly? (Flat Head Syndrome)

Plagiocephaly, also known as baby flat head syndrome, is when a baby's head has a flat spot or is misshapen.

It's caused by prolonged pressure to the skull from the baby spending a lot of time on their back or other factors like positioning in the womb.

Download Resource: A Parent's Guide to Plagiocephaly

The condition is common and estimated to affect approximately 1 in 2 (47%) infants¹. Where 1 in every 4 babies¹ have severe cases. When the head shape is determined to be moderate to sever, experts will recommend helmet therapy for treatment.

Twins Quinn and Violet in doc bands lying together

What does plagiocephaly look like?

Plagiocephaly head shapes can range from mild to severe and even occur in combination with one another. Here are some common characteristics of each:

plagiocephaly head shape diagram

Plagiocephaly Head Shape

  • The back of the head is flat on one side
  • The baby's head shape appears skewed when viewing from above
  • Misalignment of the ears/ear canal
  • Asymmetry in the facial features
brachycephaly head shape diagram

Brachycephaly Head Shape

  • The baby's head shape is wider than normal
  • The back of the head is flat and lacks curvature
  • Facial features lack proportion (i.e. the eyes may seem too small for the face)
combination plagiocephaly and brachycephaly head shape diagram

Combination Head Shape

  • A combination of plagiocephaly and brachycephaly traits
  • Head is wider and taller than normal
  • Forehead is sloped
  • Ears and eyes appear misaligned
  • Head shape resembles a distorted trapezoid from above

Head shapes ranging from normal to severe

Parents spend so much time with their baby, recognizing an abnormal head shape can sometimes be difficult. Below are some examples of mild to severe plagiocephaly and brachycephaly, along with a normal head shape for comparison.

Plagiocephaly | View of the head shape from above

View of a plagiocephaly head shape from above ranging from normal to severe

Brachycephaly | View of the head shape from the side

View of a brachycephaly head shape from the side, ranging from normal to severe

What causes plagiocephaly?

Babies’ heads are soft and therefore sensitive to external forces — even gentle ones.

Whether in the womb or in the baby's daily routine, these forces applied to the baby's skull can cause deformity.

Back sleeping

The relationship between back-sleeping and plagiocephaly in infants is well-documented. Prolonged pressure applied to the back of the skull during sleep can result in flattening.

Restrictive Devices

Restrictive devices restrict the baby's natural movement and/or contribute to prolonged periods of time on their backs. Some examples of these devices include car seats, "smart" sleepers, automatic rockers, strollers, etc.


Congenital Muscular Torticollis (CMT) is a condition in which the neck muscles are abnormally tight on one side. This causes the baby’s head to tilt toward one side which they will also favor while sleeping.

Premature Birth

Premature babies have especially soft skulls, making them even more susceptible to misshaping. These babies often spend extended periods in NICU with the head in a fixed position. Premature babies also have a higher likelihood of experiencing physical delays, which can hinder the normal movement of the head.

Positioning in the Womb

Babies who become stuck in a singular position in the womb are at risk of developing plagiocephaly. A breech orientation can also lead to an abnormal head shape.

Multiple Births (Twins)

Plagiocephaly is common in cases of multiples where limited space in utero can lead to distortion of the head.

Twins in doc bands wearing t-shirts that say dream big!

Will it affect my baby's brain development?

Flat spots caused by pressure to the head do not have any negative or harmful effects on your baby's brain development.

However, if you leave severe cases untreated, there are other challenges to consider for your child later in adolescence and adulthood.

  • Noticeable facial asymmetry and misshapen head into adult life
  • Poor-fitting eyeglasses and/or safety equipment
  • Visible flat areas with short or cropped hairstyles
  • Jaw misalignment resulting in a crossbite or underbite which can affect breathing, leading to other conditions like sleep apnea
Head shape concerns? We can help.
Get a Free Evaluation

Will flat spots go away on their own?

While repositioning can sometimes correct mild flatness in babies up to four months old, research has shown that moderate to severe plagiocephaly is not likely to self-correct.

But there is some complexity to this and we must also grasp why age is a significant factor with treatment.

Why age is an important factor

At a young age, it's completely natural for babies to have very soft skulls. In fact, the baby having a malleable skull allows it to be flexible enough to fit easily through the birth canal.

Head size growth chart from birth to 2 years of age

Your baby's head will begin to grow with age, however, the skull will also harden as time continues. A baby's head doubles in size within the first 6 months of age. The brain growth slows significantly by 2 years of age, and the head shape mostly sets for life.

baby in doc band smiling with mother

How is plagiocephaly treated?

Foremost, it's important to understand if your baby's flat spots are because of a positional deformity. In other words, if pressure to the head is what causes their flat spots.

Your provider can examine your baby's head shape or you can go to a plagiocephaly treatment clinic for an evaluation.

Tummy time

Tummy time is a simple countermeasure that reduces the amount of time the baby spends on their back. Parents practice this while the baby is awake and encourage them to lift their heads.

It helps them develop core motor skills and the strength necessary to begin rolling over, crawling, and eventually standing up. It also allows your baby to move their head on their own without assistance needed from a parent or guardian.

Reposition the head

Repositioning involves turning their head while sleeping or in a convenience device (i.e. strollers or car seats). This is especially helpful if your baby favors a particular side of the head while in a sleeping position.

For instance, your baby may favor a particular side while they're sleeping. Repositioning helps reduce the risk of flat spots and also prevents additional pressure put onto one that may already exist.

Hold your baby

Similar to tummy time, this helps reduce pressure to parts of the head with flat spots. It also allows your baby to spend less time in restrictive devices that could be the cause of their condition.

When does a baby need helmet therapy?

Cranial orthotics are devices that help to reshape the infant’s head and bring back normal curvature.

Generally, experts recommend helmet therapy for babies when:

  • There has not been any improvement to the flat spots over time, or after repositioning, tummy time, and/or physical therapy

  • They are between 4-6 months and the flat spot(s) have not improved over time

  • They are older than 4-6 months and have a form of plagiocephaly considered moderate to severe

  • They are older than 6 months and the flat spot(s) persist

Schedule a Free Head Shape Evaluation

When is the best time to begin treatment?

With rapid skull development in the early months, a flat spot can form in as little as one week. The period of time is also the most effective window for treatment since this is when most of the head growth occurs.

Age Average Time to Treat
<4 months 5-7 weeks
4 months 6-9 weeks
5 months 8-10 weeks
6 months 2.5-3.5 months
>7 months 3.5-4 months

Frequently asked questions

Should I still put my baby to sleep on their back?

Yes, having babies sleep on their backs saves lives! According to the American Academy of Pediatricians, the move to back sleeping, known as the Back to Sleep campaign, has reduced SIDS (Sudden Infant Death Syndrome) by more than 50%.

Is plagiocephaly common?

The latest studies show that nearly 1 in 2 (47%) infants today have some degree of plagiocephaly. 1 in 10 babies have a severe enough degree that experts would recommend treatment with a cranial orthotic.

Is plagiocephaly preventable?

Simple at-home practices including supervised tummy time and repositioning techniques are known to prevent and improve abnormal head shapes up until about four months of age. Additionally, limiting the use of convenience devices, such as car seats, infant carriers and swings, is also recommended.

How do I know if my baby needs helmet therapy?

You can follow our at-home assessment to get a better understanding of your baby’s head shape.

Please note that this assessment is not meant to replace the diagnosis of a medical professional. If you’re concerned about your baby’s head shape, you can schedule a free evaluation at the clinic location nearest you.


  1. 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. Mawji A, Vollman AR, Hatfield J, McNeil DA, Sauve R.