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What is plagiocephaly?

Plagiocephaly, also known as deformational plagiocephaly or positional plagiocephaly, is a common and treatable condition that causes a baby’s soft skull to become flattened in one area due to continuous pressure on that part of the head.

Plagiocephaly can develop when a baby consistently sleeps in the same position. It’s often most noticeable during the first few months of life and usually peaks between 6 weeks and 3 months. Plagiocephaly tends to improve once babies gain strength and muscle maturity, tolerate longer stretches of tummy time, and achieve motor milestones such as rolling over belly to back and back to belly.

Plagiocephaly | Symptoms & Causes

What are the symptoms of plagiocephaly?

Typically, the only symptom of plagiocephaly is a flattened appearance of a baby’s head. It’s also not uncommon to notice a bump on the back of your baby’s head, asymmetrical ears, or an uneven forehead.

Plagiocephaly isn’t painful and doesn’t affect a baby’s day-to-day life or abilities.

What causes plagiocephaly?

Plagiocephaly is most often caused by a baby sleeping regularly in one position. Some studies show that 20 to 25 percent of infants who sleep on their backs develop some degree of plagiocephaly. Other causes of plagiocephaly include:

  • Womb position: Babies who are part of a multiples birth, developed in a small uterus, or experienced low amniotic fluid may be at increased risk of plagiocephaly. Infants’ skulls often get misshapen from the birthing process, referred to as skull molding. This molding typically resolves quickly within the first week of life.
  • Prematurity: Many premature infants spend extended periods in a fixed position while in the neonatal intensive care unit, which can lead to plagiocephaly. Some NICUs have started implementing cranial molding cups to help prevent plagiocephaly.
  • Muscular torticollis: A shortening or tightening of the muscle in one side of the neck that causes the head to tilt in one direction.

Plagiocephaly | Diagnosis & Treatments

How is plagiocephaly diagnosed?

In most cases, a clinician can diagnose plagiocephaly by examining your baby and reviewing their medical history. Testing is usually unnecessary.

How is plagiocephaly treated?

Plagiocephaly is treated through non-surgical methods, including:

Positional changes

Changing your baby’s sleeping and resting positions can help reduce pressure on their skull, which is highly malleable during the first few months of life. Your doctor may recommend the following:

  • having your baby spend time on their tummy throughout the day
  • turning your baby’s head position during the night when sleeping on their back
  • eliminating swaddling during waking hours at around one month and entirely around three months
  • ensuring your baby doesn’t spend too much time lying down while awake


Many infants with plagiocephaly — especially those born with an imbalance of the neck muscles, such as muscular torticollis — will benefit from exercises to increase neck range of motion. Sometimes, referral for an early intervention evaluation or to a pediatric physical therapist may be beneficial. These providers can teach you exercises and position changes to help with the torticollis.

The Perfect Noggin (specialized sleep surface)

The Perfect Noggin was developed by a plastic surgeon at Boston Children’s to reduce and prevent head-flattening in infants. The contoured surface of the Perfect Noggin aligns a baby’s head and torso in the best position for breathing, with a recess that cradles the back of their head to promote natural head shape and symmetry. This device is best implemented in early infancy before babies start to roll over.

Corrective helmet

Corrective helmets are most effective in infants from 4 to 8 months with moderate to severe head flattening. Corrective helmets must be prescribed by a licensed clinician, and carefully monitored and adjusted regularly. We help refer our patients to highly qualified orthotists who fit your child with helmets that can gently correct head shape as comfortably as possible.

Most babies need to wear the helmet 22 to 23 hours a day for an average of three months but potentially up to their first birthday to benefit most from the treatment. As your baby grows, their helmet will need periodic adjustments.

It’s also important to note that even with a helmet, your child’s head most likely won’t be perfectly round at the end of treatment.

How we care for plagiocephaly at Boston Children’s

The Plagiocephaly Clinic at Boston Children’s Hospital is at the forefront of diagnosing and treating plagiocephaly and other craniofacial conditions through our collaborative, multidisciplinary approach to care. We’re often able to diagnose some of these conditions before birth. This could mean referring an infant with plagiocephaly to a plastic and neurosurgery clinician to rule out craniosynostosis. Craniosynostosis is a condition where one or more of the skull bones fuse prematurely, resulting in an abnormal head shape that can resemble plagiocephaly. However, unlike plagiocephaly, craniosynostosis is treated surgically.

Plagiocephaly | Frequently Asked Questions

How common is plagiocephaly?

Plagiocephaly has become more common since the American Academy of Pediatrics began advising parents to place infants to sleep on their backs to prevent sudden infant death syndrome (SIDS). Approximately 20 to 25 percent of infants who sleep on their backs develop some degree of plagiocephaly. Although this recommendation has increased the number of babies with plagiocephaly, it has also greatly reduced the number of babies lost to SIDS.

What makes a baby more likely to develop plagiocephaly?

Any baby who has limited ability to reposition their head can experience flattening. Babies with other risk factors, such as muscular torticollis (an imbalance in the neck muscles), who are part of a multiple birth (i.e., twins), or who developed in a small uterus may be more likely to have plagiocephaly.

When does plagiocephaly develop?

Most parents and caregivers notice the flattening of their baby’s head at around 6 to 8 weeks old.

Why does head flattening occur?

Flattening occurs when the infant’s growing head meets the resistance of a flat resting surface. It’s similar to how a pumpkin develops a flat spot in a field: Since it can’t grow into the ground, it conforms to the ground’s flat shape.

When does head flattening stop?

Head flattening usually stops when babies gain head control, typically at around three months. A premature infant or a baby with developmental delays may have flattening for longer since they may take longer to reach physical milestones such as head control and rolling over.

Can head flattening be prevented?

There are three main ways to help prevent head flattening in infants:

  • repositioning the baby often to avoid prolonged periods on their back
  • changing the baby’s sleep surface from flat to concave
  • using a hospital-approved sleeping surface or device up until the baby starts rolling over. Boston Children’s Hospital has developed an alternative sleep surface, called the Perfect Noggin, to help reduce or prevent head flattening in some babies.

It’s important to know that these strategies don’t work with all babies and may not help to reverse any flattening that has already occurred.

Does plagiocephaly cause any medical problems?

No, there are no known medical problems linked to plagiocephaly. Plagiocephaly is a treatable condition that causes cosmetic changes in a baby’s skull shape. Plagiocephaly responds well to non-surgical treatments, such as:

  • changes in sleep position
  • offering tummy time during the day
  • exercises or physical therapy
  • helmeting
What is the difference between plagiocephaly and craniosynostosis?

Craniosynostosis is the premature fusion of one or more joints that connect the bones in the skull. Unlike plagiocephaly, craniosynostosis may limit the size of the skull, increase pressure inside the skull, and damage brain growth. In plagiocephaly, there is no fusion of the skull joints.

Plagiocephaly | Programs & Services