In the past, babies rarely got funny shaped heads because they slept on their tummies. When we started putting babies to sleep on their backs 20 years ago, unusual head shapes started to be noticed. The pictures above show three types of head shapes: symmetrical, plagiocephaly (flat on one side) and brachycephaly (flat along the back).

A baby’s head will take on an unusual shape if he spends more time sleeping with his head in one direction. This occurs because more pressure is applied to one area and the head “molds” the corresponding location. In most cases, this represents a temporary finding that will resolve over time.

When pediatricians examine babies with unusual head shapes, we look for two problems. This first is a common condition called congenital muscular torticollis. If a baby has torticollis, the neck muscles that bend and rotate the head are tighter on one side causing the baby to spend more time turned in one direction when asleep. It many cases, it will also be noticed when the baby is awake. Over time, this will deform the shape of the skull. Torticollis is treated with physical therapy or watchful waiting depending on its severity.

The second is a rare condition called craniosynostosis. In this situation, one of the skull bones is not growing properly because it is “stuck” to the opposing bone, causing a misshapen head. If there is a question whether your baby has this condition, he will be x-rayed or referred to a pediatric specialist (neurosurgeon or plastic surgeon) for a thorough evaluation.

For the past 10 years or so, companies have sprung up to “fix” plagiocephaly and other asymmetric head shapes. A handful of studies have been published showing that this is not necessary. If your baby’s head is flat on the side or back because of positional forces, the problem will usually resolve by 2 to 3 years of age. The head may not look perfect, but a corrective helmet won’t make it look any better.