Plagiocephaly

Positional plagiocephaly means asymmetric head shape — typically, flattening in one area. It is caused by pressure on the bones of the skull either before or after birth. The flattening may be obvious or barely noticeable.

Plagiocephaly isn't thought to be genetic. Possible causes include:

  • Torticollis, or muscle tightness on one side of the neck — This makes the baby prefer holding the head to one side or in one position.
  • Prematurity — The baby's head rests on a flat surface in the isolette for several weeks rather than in the womb.
  • In-utero crowding — This can occur during a first pregnancy or pregnancy with twins or multiples; if the mother has large fibroids or an abnormally shaped uterus; or because of early descent into the birth canal.
  • Sleep habits — If your baby prefers to sleep facing in one direction all the time, this can cause flatness on that side.

Positional plagiocephaly is diagnosed based on an examination by a health care provider experienced in craniofacial anomalies. In addition to the flattening, the baby's ear is usually displaced forward on the same side as the flatness in the back.

Sometimes, X-rays of the skull are needed to determine whether a baby has positional plagiocephaly or a condition called craniosynostosis, in which one or more bones of the skull close prematurely.

The first line of treatment is often to keep the baby off the flat part of the head as much as possible by repositioning the head during sleep, while still keeping the baby on his or her back. At night and during nap time, place a roll of fabric under the shoulder and hip of the flat side and attach it to your baby's bed clothes with pins or tape, so your baby can't roll away.

In addition, keep your baby off the flat area by:

  • Increasing "tummy time," when you play with your baby on his or her stomach
  • Avoiding the car seat unless you're in the car, and using a baby front pack instead of a stroller
  • Positioning the car seat so your baby will turn off the flat side when looking out the window
  • Placing toys and mobiles so they attract your baby's attention to turn off the flat side

Repositioning usually works well when started early, before 6 months of age. If the deformity persists, helmet therapy may be recommended. For helmet therapy, a specialist constructs a custom helmet that fits the child's head snugly except for where the head is flat. As your child's brain grows, the skull fills in the flat area and becomes rounder.

If your child's positional plagiocephaly is caused by torticollis, we may recommend specific exercises to perform every time you change your baby's diaper. The exercises consist of stretching your baby's chin toward the opposite shoulder 10 times and tipping the ear to the opposite shoulder 10 times.

Reviewed by health care specialists at UCSF Benioff Children's Hospital.