Infant Skull Shape Differences — CranioWell Orthotics & Prosthetics Center

Infant skull shape differences have become more common. Since 1992, the American Academy of Pediatrics has recommended back sleeping to reduce suffocation and Sudden Infant Death Syndrome (SIDS) risk. One consequence of back sleeping can be an asymmetric or flattened head. Known as deformational plagiocephaly, this pattern reflects asymmetry from repeated pressure on the same area of the head.
Changes can begin around 1–2 months of age. At birth, cranial bones are soft and flexible, and plates are not fully fused so the brain can grow. When an infant is repeatedly placed in the same orientation, the skull can flatten.
Some infants are born with asymmetric head shapes. Babies from multiple pregnancies may have limited movement in the womb; labor can also temporarily flatten the skull. Other causes include muscular torticollis, which tightens neck muscles so the infant turns only one way to sleep.

Early Intervention Matters in Skull Shape Differences

Clinical experience and studies are reassuring: plagiocephaly does not harm the infant’s brain or growth. Repositioning in the first months can help. Shape can also be improved with positioning strategies or several months of a cranial remolding helmet.
Because of back sleeping and increased use of devices that keep infants on their backs—car seats, strollers, inflatable seats, and swings—more infants present with this pattern than two decades ago.

If asymmetric head shape worries you, talk with your pediatrician. Any infant with an unusual skull shape should be evaluated to rule out more serious conditions such as craniosynostosis, in which sutures fuse too early and limit space for brain growth. For deformational plagiocephaly or craniosynostosis, early care between about 2 and 4 months is important.

CranioWell focuses on healthy cranial shape. Evaluation by the infant’s physician should come first to help exclude craniosynostosis, followed by detailed assessment.
If the infant is seen early enough, repositioning therapy can often be used. After 4 months of age, or when the head is markedly misshapen, a remolding helmet may be needed. Helmet fitting is provided at CranioWell Orthotics & Prosthetics Centers.

Helmet Support for Infant Head Asymmetry

Between about 4 and 6 months, the head is soft and growing quickly. A helmet contacts fuller areas and leaves room so growth is directed into flatter zones. Each infant remolding helmet is custom-made. Typical wear is about 23 hours a day for an average of four months. Infants are usually adaptable both in cranial change and in adjusting to the helmet.

Positioning Tips to Prevent or Ease Plagiocephaly

• Aim for at least one hour of supervised tummy time daily. This also strengthens neck and arm muscles while supporting motor skills.
• When you go out, leave the car seat in the car. Constant carrying in the seat can worsen shape. Use a front carrier or sling instead to reduce pressure on the back of the head.
• Limit time in swings and rockers that also press on the back of the head.
• Alternate which end of the crib the infant sleeps at each night so natural looking outward changes pressure points.