Passage through the birth canal often makes a newborn's head appear pointy or elongated for a short time. It's normal for a baby's skull, which is made up of several separate bones that will eventually fuse together, to be slightly misshapen during the few days or weeks after birth.
But if you've noticed that your baby is developing a persistent flat spot, either in the back or on one side of the head, it could be a sign of positional plagiocephaly. Also known as flattened head syndrome, this can occur when a baby sleeps in the same position repeatedly or because of problems with the neck muscles.
Fortunately, positional plagiocephaly usually is easy to treat, and with appropriate intervention will correct itself by the time a child is 1 year old.
About Positional Plagiocephaly
Positional plagiocephaly is a disorder in which the back or one side of an infant's head is flattened, often with little hair growing in that area. It's most often the result of babies spending a lot of time lying on their backs or often being in a position where the head is resting against a flat surface (such as in cribs, strollers, swings, and playpens).
Because infants' heads are soft to allow for the incredible brain growth that occurs in the first year of life, they're susceptible to being "molded" into a flat shape.
The number of positional plagiocephaly cases increased sixfold from 1992 to 1994, occurring in approximately 33 out of every 10,000 births. This dramatic increase started when the American Academy of Pediatrics (AAP) began its "Back to Sleep" campaign, which continues to recommend that babies sleep on their backs to reduce the risk of sudden infant death syndrome (SIDS).
Since the AAP's campaign, the incidence of SIDS in the United States has decreased by almost 40% while the incidence of flattened head syndrome has risen. Still, the prevention of SIDS is worth the increased risk of a flattened head, especially because positional plagiocephaly will often correct itself with appropriate intervention.
Causes of Positional Plagiocephaly
The most common cause of a flattened head is a baby's sleep position. Because an infant sleeps so many hours on the back of his or her head, the head sometimes assumes a flat shape.
Another thing that can contribute to flattening is torticollis, which means the neck muscles are too tight, have inadequate tone, or are shorter on one side than the other, causing the head to tilt one way while the chin points in the opposite direction.
Premature babies are more prone to positional plagiocephaly — their skulls are softer than those of full-term babies, and they spend a great deal of time on their backs without being moved or picked up because of their medical needs and extreme fragility after birth, which usually requires a stay in the neonatal intensive care unit.
A baby might even start to develop positional plagiocephaly before birth, if pressure is placed on the baby's skull by the mother's pelvis or a twin. In fact, it's not at all unusual to see plagiocephaly in multiple birth infants.
But the differences in head shape seen in children with positional plagiocephaly shouldn't be confused with those caused by craniosynostosis, a more serious condition that occurs when skull bones fuse together too soon, causing an abnormal skull shape and possible brain damage if the condition is not corrected. A child with craniosynostosis may have deformities in the front of the head and a bony ridge over the abnormally fused skull bones. Craniosynostosis is usually corrected with surgery.
Signs and Symptoms
Positional plagiocephaly is usually easy for parents to notice. Typically, the back of the child's head (called the occiput) and the ear on the flattened side may be pushed forward. In severe cases, there may be bulging on the side opposite from the flattening and the forehead may be asymmetrical (or uneven), although this is unusual in full-term infants. If torticollis is the cause, the neck, jaw, and face may be asymmetrical.
Most often, a doctor can make the diagnosis of positional plagiocephaly simply by examining your child's head, without having to order lab tests or X-rays. The doctor will also note whether regular repositioning of your child's head during sleep successfully reshapes the growing skull over time (craniosynostosis, on the other hand, typically will worsen).
If there's still some doubt, X-rays or a CT scan of the head will show the doctor if the skull bones are normally separated or if they fused together too soon. If the bones aren't fused, the doctor will probably rule out craniosynostosis and confirm that the child has positional plagiocephaly.
Treatment for positional plagiocephaly caused by sleeping position is usually easy and painless, entailing simple repositioning of babies during sleep to encourage them to alternate their head position while sleeping on their backs.
Even though they'll probably move around throughout the night, alternating sides is still beneficial. Wedge pillows are available that keep babies lying on one side or the other, but be sure to check with your doctor before using one to ensure that it's appropriate and safe for your baby. The AAP does not recommend routinely using any devices that might restrict the movement of an infant's head.
In addition, you may want to consider moving your baby's crib to a different area of the room. If there's something in the room (a window or toy, for example) that's catching your baby's attention and causing him or her to hold the head in a similar position day after day, moving the crib will coax your child to look at it from another position.
Always be sure your baby gets plenty of supervised time on the stomach while awake during the day. Not only does "tummy time" promote normal shaping of the back the head, it also helps in other ways. Looking around from a new perspective encourages your baby's learning and discovery of the world. Plus, it helps babies learn to push up on their arms, which helps develop the muscles needed for crawling and sitting up. It also helps to strengthen the neck muscles.
If torticollis is the cause of your baby's flattened head, a course of physical therapy and a home exercise program will usually do the trick. A physical therapist can teach you exercises to do with your baby involving stretching techniques that are gradual and progressive. Most moves will consist of stretching your child's neck to the side opposite the tilt. Eventually, the neck muscles will be elongated and the neck will straighten itself out. Although they're very simple, the exercises must be performed correctly.
For kids with severe positional plagiocephaly, doctors may prescribe a custom-molded helmet or head band. These work best if started between the ages of 4 and 6 months, when a child grows the fastest, and are usually less helpful after 10 months of age. They work by applying gentle but constant pressure on a baby's growing skull in an effort to redirect the growth.
But never purchase or use any devices like these without having your child evaluated by a doctor. Only a small percentage of babies wear helmets. The decision to use helmet therapy is made on a case-by-case basis (for example, if the condition is so severe that a baby's face is becoming misshapen or the parents are very upset). Although helmets might not improve the outcome in all children, some kids with severe torticollis can benefit from their use.
The outlook for babies with positional plagiocephaly is excellent. As babies grow, they begin to reposition themselves naturally during sleep much more often than they did as newborns, which allows their heads to be in different positions throughout the night. After babies are able to roll over, the AAP still recommends that parents put them to sleep on their backs, but then allow them to move into the position that most suits them without repositioning them onto their backs.
Most skull-flattening deformities are self-corrected by the time the child is 1 year old. A persistent, severe, or cosmetically obvious deformity can be corrected with reconstructive surgery between 12 and 18 months of age, but very few cases require this.
It's important to remember that plagiocephaly itself does not affect your child's brain growth or cause developmental delays or brain damage.
Babies should be put down to sleep on their backs to help prevent SIDS, despite the possibility of developing an area of flattening on the back of the head. However, alternating their head position every night while they sleep and providing lots of tummy time and stimulation during the day while they're awake can reduce the risk of positional plagiocephaly.
Reviewed by: Steven Dowshen, MD
Date reviewed: February 2008