What Is Positional Plagiocephaly?

Fixing Baby's Misshapen Head

Cranial Remolding helmet worn for the treatment of plagiocephaly

Box5 / Getty Images 

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Positional plagiocephaly is the flattening of the back or sides of an infant's head. This very common condition, which is also called posterior or deformational plagiocephaly and flat head syndrome, is primarily due to sleep position and tight neck muscles, called torticollis. Tight or weak neck muscles prevent a newborn from turning their heads, which can result in excess wear and weight on one spot.

While it may be alarming to notice flattened areas on your baby's head, the condition does not impact brain development. In most cases, the cranial shape eventually returns to normal as your baby grows, usually by age 1. As long as the flat spot is caused by positioning (rather than an underlying issue), the condition is rarely medically worrisome.


In addition to the telltale flat spots on the back or side of the head, in more extreme cases, positional plagiocephaly may also result in other parts of the face becoming misshapen. Sometimes, one ear appears to be pushed forward in response to the flattening of the skull. The baby's forehead and/or eyes may bulge forward slightly. The hair may be worn off from the flattened area as well.


Pediatricians routinely check for flat spots on the head during well-child visits. A diagnosis of positional plagiocephaly is done via visual examination of the child's skull as well as measurements. The asymmetrical shape of the head is usually easily recognizable and parents have often spotted the condition before it is diagnosed by a doctor.

The condition is usually first noticed when an infant is about 2 to 3 months old but can be noticeable by around 6 weeks. Cases range from mild to severe. The sooner treatments begin, the better and quicker the skull grows back into its typically symmetrical, rounded shape.

It is easiest to see changes in a baby's skull when looking at their head from above.

Although it's usually unnecessary, additional testing can be done if the diagnosis is unclear, especially if your pediatrician suspects another issue is at play. This testing may include a skull X-ray or a head CT, which are better options than a plain X-ray in detecting if the sutures of the skull (the fibrous joints where the bones connect) are still open and to rule out craniosynostosis and other potential disorders.


Another possible cause for an infant's cranial flat spots is a similar-looking but more serious condition called craniosynostosis. Craniosynostosis is a birth defect in which the bones of the skull have fused together prematurely, which causes problems as the brain and skull grow.

In infants with coronal synostosis, a type of craniosynostosis, the coronal sutures of the skull fuse early, causing flattening of one side of the forehead and a compensatory bulging of the forehead on the other side. In comparison to positional plagiocephaly, the backs of these infants' heads appear normal and not flat or misshapen at all.

Another form of craniosynostosis, in which the lambdoidal suture closes early, can cause a flattening of one side of the back of an infant's head and bulging of the forehead on the opposite side of their head. This is in contrast to what happens in positional plagiocephaly, in which the flat spot and bulge are both on the same side of the infant's head.

Sagittal craniosynostosis or scaphocephaly is another type of craniosynostosis in which babies have a long, thin skull from front to back. Lastly, children can have trigonocephaly or metopic craniosynostosis, which is characterized by a triangular-shaped forehead.

Craniosynostosis is very rare. It's estimated that only approximately 1 in 2,500 babies is born with this condition.

You might get a referral to a craniofacial specialist if your pediatrician isn't sure whether your child has positional plagiocephaly or craniosynostosis.


Newborns have soft skulls with soft spots and unfused bones, characteristics that allow them to be delivered through the relatively narrow pelvis and vaginal canal. However, these traits also make them susceptible to developing flat spots on their heads. This is particularly true for premature infants whose skulls are even softer—but even full-term infants are at risk for this very common condition.

It is estimated that a third to a half of all infants develop this condition to some degree, which can progress very rapidly in the first weeks of life. Risk factors include premature birth, male sex, and multiples.

The causes of positional plagiocephaly are complicated, as they are tied to keeping babies safe during sleep. The American Academy of Pediatrics' Back to Sleep campaign to put babies to sleep on their backs has dramatically decreased the number of SIDS deaths since it was begun in 1992. Unfortunately, one consequence of this practice has been a dramatic rise in cases of positional plagiocephaly.

Sleeping on Their Backs

Flattened heads are linked to putting babies to sleep on their backs because, in the supine position, it's more challenging for babies to move their heads from side to side. So, the head may stay in the same spot for hours at a time. Staying in one position too long can exert a lot of force on a baby's head, causing a flat spot to develop and the head shape to become asymmetrical.

Hard Headrests

Infants can also be at risk for positional plagiocephaly if they stay in a car seat, bouncy seat, or swing too long. The risk is thought to be greatest when the baby's head is against harder surfaces, such as the hard plastic that is used to make some seats or swings.

Preference for One Side

Additionally, many infants may develop positional plagiocephaly because they simply prefer to lie in one position all of the time.

Tight Neck Muscles

Other babies have this problem because they have limited neck motion due to congenital torticollis and can't help lying in the same position. These children have limited motion on one side of their neck and may have a hard mass on their neck muscles, preventing easy movement of the head from side to side.

See your pediatrician to confirm the diagnosis and ensure that there isn't a different problem causing your baby's head to be shaped this way.


The best treatment for positional plagiocephaly is to prevent the condition from happening—and the same strategies will work for both prevention and treatment. Since the condition is caused by too much continuous pressure on one part of your infant's head, you can often curtail it by alternating the positions that your infant stays in.

Additionally, the flattened spots usually smooth out to a more rounded shape on their own as your child's brain grows and their skull bones fuse and harden. Until then, the following treatments can help:

Vary Head Position

The increased risk of developing flat spots on the head does not mean that you should stop putting your child to sleep on their back. What you should do is alternate your child's head position each time you put them to sleep. Switching sides will keep them from putting pressure on the same spot and can help improve neck mobility.

Most babies will grow out of positional plagiocephaly, but some infants don't improve just by making positional changes and do need more extensive treatment.

Tummy Time

Aim for your baby to spend minimal time lying on their back while awake. Spending more time on the stomach (prone position) in tummy time when your baby is awake and being supervised is also a good idea. In addition to reducing flattening of the head, tummy time strengthens your baby's neck, arms, and core muscles.

Carry Your Baby

Another alternative to stiff baby seats is to use an infant sling, carrier, or wrap, as they put less pressure on your child's head. You can also simply hold your child in your arms, and/or use a stationary bouncer (do not use mobile walkers as these are not safe) once your child is old enough to sit in one.

Helmets and Bands

When positional changes don't result in sufficient improvement, more obtrusive mechanisms can be tried. These options include skull molding helmets or band therapy, which involves progressively adjusting the helmet or band to encourage skull growth in flattened areas and discourage it from any bulging areas. Doctors recommend starting these treatments by five months of age.

However, while studies show that short-term improvement is often seen with these devices, final results are usually the same as for babies who did not use helmets. Because using helmets can have serious drawbacks, such as odor, skin rash, or discomfort, many practitioners do not recommend them for mild or moderate cases. In severe cases, though, helmets are often beneficial.

Physical Therapy

Infants with torticollis usually need neck exercises as part of their treatment as well. These children often keep their head in the same position and have trouble turning their head and neck. Neck exercises, perhaps with the help of a pediatric physical therapist, can help these babies improve their neck mobility.


Surgery is rarely needed but may be considered in severe cases that do not resolve with other measures. While a misshapen head shape is primarily an aesthetic issue, cases with extensive bulging around the eyes, forehead, cheek, or jaw can compromise vision, chewing, and the integrity of the jaw. In these situations, surgery may be used to correct any functional issues.


Prevention and treatment measures can be especially important for infants at higher risk of positional plagiocephaly, including preemies, multiples, and infants with poor muscle tone. Ideally, start implementing prevention strategies during the newborn period, when an infant's skull is maximally shapable.

When efforts are made to reduce the amount of time a baby is in a position that exerts undue pressure on any flattened spots on their head, improvement usually occurs over a two- to three-month period. If you do not see improvement or the deformity continues to worsen, then your child will likely need an evaluation by a pediatric craniofacial surgeon or a pediatric neurosurgeon.

A Word From Verywell

Discovering that your baby's head is misshapen can be upsetting. Luckily, simple positional treatments can prevent, halt, and reverse positional plagiocephaly. Most babies will completely outgrow any flattened cranial spots that occur—and hair will likely cover any residual effects. Most importantly, trust that placing them on their back to sleep (even if they develop a flat spot) may very well save their life.

6 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Centers for Disease Control and Prevention. Facts about craniosynostosis.

  3. Mawji A, Vollman AR, Fung T, Hatfield J, McNeil DA, Sauvé R. Risk factors for positional plagiocephaly and appropriate time frames for prevention messagingPaediatr Child Health. 2014;19(8):423-427. doi:10.1093/pch/19.8.423

  4. American Association of Neurological Surgeons. Positional plagiocephaly.

  5. Rowland K, Das N. PURLs: Helmets for positional skull deformities: a good idea, or not?J Fam Pract. 2015;64(1):44-46.

  6. Jung BK, Yun IS. Diagnosis and treatment of positional plagiocephaly. Arch Craniofac Surg. 2020;21(2):80-86. doi:10.7181/acfs.2020.00059

Additional Reading

By Vincent Iannelli, MD
Vincent Iannelli, MD, is a board-certified pediatrician and fellow of the American Academy of Pediatrics. Dr. Iannelli has cared for children for more than 20 years.