A flexible helmet worn 23 hours a day helps correct abnormal skull growth.

Six separate bones make up the cranium (skull). The lines where these bones come together are called sutures. In an adult, these sutures are fused together and the skull becomes rigid to protect the brain. However, in an infant these sutures are flexible. There are also two open spots between the skull bones called fontanels. These open spots and the flexible sutures allow the bones to shift and move so the skull can fit through the birth canal during delivery. It is normal for a baby's head to be slightly misshapen during the weeks immediately following birth.

However, there are two problems that can actually permanently deform an infant's head. One can be easily treated with a corrective helmet; the other requires surgical correction.

Unintended Result

Because the baby's skull is thin and flexible, constant pressure on one area can reshape, flatten or deform it. This condition is called plagiocephaly (play-gee-oh-seph-alee) and it occurs when one bone in the skull becomes deformed, causing repositioning of the other bones. Plagiocephaly does not cause damage to the baby's brain, but severe cases can lead to significant disfigurement, including deformities of the ear, forehead and eye socket on the side of the flattening.

Plagiocephaly is often caused by an infant being left in the same position day after day. Between cribs, strollers, car seats and carriers, some babies spend almost 24 hours a day on their backs with their heads laid against a firm object, like a mattress.

"This is an unintended result of the recent 'back to sleep' campaign which was started in an effort to reduce the number of cases of Sudden Infant Death Syndrome (SIDS), explained Bruce Kaufman, M.D., Neurosurgery Today pediatric editor and a neurosurgeon in Missouri.

"The problem is that Mom and Dad took the instructions too much to heart. Their baby never gets off its back. As a consequence, neurosurgeons have witnessed a dramatic increase in plagiocephaly, or flattening of the bones in the back of the head. The solution is as simple as placing the baby on its side or tummy when it's not sleeping to relieve the constant pressure on the back of the head. The direction the child is placed in the crib should also be varied."

Babies with plagiocephaly have a distinguishable flatness on one side of the back of their heads and also commonly have little hair growing in that area. Treating an infant with plagiocephlay starts with simple repositioning. In moderate to severe cases, the baby is fitted with a custom helmet, which he or she wears for 23 hours a day. The rounded helmet does not allow the head to constantly fall into one position because it distributes the forces equally around the head. The helmet also takes advantage of the child's rapid brain growth by allowing skull expansion into the flattened area.

More Serious Problem

The second, more serious, problem that can affect the shape of an infant's head is craniosynostosis. Normally, the bones in the skull fuse slowly over time with almost 80 percent of fusion taking place by the second birthday. However, if the suture lines close early, the baby's head becomes misshapen.

"When only one suture closes too early, the skull accommodates the brain growth by expanding and bulging in another direction," Dr. Kaufman explained. "Most cases of craniosynostosis will require surgery and use of a positioning helmet to develop the correct the skull shape, particularly if more than one suture is affected".