The shape of an infant’s head is a common concern for new parents, often due to visible flattening or asymmetry. The skull is initially soft and flexible to accommodate passage through the birth canal and rapid brain growth. Changes in head shape, including flat spots, are normal in early infancy because the skull plates are not yet fused. Understanding the physiology of these malleable bones is the first step in managing any changes that may arise. This guide provides actionable information on preventing and treating common changes in an infant’s head shape.
Understanding Infant Skull Molding
An infant’s skull is composed of several separate bony plates connected by flexible joints called cranial sutures. At the intersection of these sutures are the fontanelles, or soft spots, with the largest one located on the top front of the head. These unfused seams allow the skull to change shape during birth, a process known as molding.
The flexibility of the skull is maintained after birth to allow for the brain’s rapid growth, which doubles in size during the first year of life. The pressure of gravity and consistent positioning against a firm surface can easily cause a skull to flatten because the bones are so pliable. The most common condition resulting from this external pressure is positional plagiocephaly, often called “flat head syndrome.”
Positional plagiocephaly occurs when an infant spends too much time with their head resting in the same position, such as while sleeping on their back or sitting in car seats and swings. This constant pressure leads to a flattening on the back or side of the head, resulting in an asymmetrical shape. A contributing factor to this preference for one side may be congenital muscular torticollis, a condition where tight neck muscles limit the baby’s ability to turn their head fully in one direction.
Proactive Strategies for Head Shape Management
The most effective approach to managing an infant’s head shape involves consistently redistributing pressure away from any flattened area throughout the day. This proactive strategy is non-medical and focuses on environmental and positional changes. The current recommendation for safe sleep is for infants to always be placed on their backs, but this must be balanced with plenty of time off the back when awake.
The primary tool for pressure redistribution is “Tummy Time,” which involves placing the baby on their stomach while they are awake and supervised. Tummy Time immediately removes pressure from the back of the head and strengthens the neck, shoulder, and trunk muscles, which improves head control. Parents should aim to start Tummy Time early, even with a newborn, with short sessions of one to two minutes, several times a day.
The total duration of Tummy Time should be gradually increased, with a goal of reaching approximately 90 minutes spread throughout the day by four months of age. To encourage head turning and muscle development, toys, mirrors, or the caregiver’s face should be positioned to the sides, prompting the baby to look in different directions. If a flat spot is present, all stimuli should be placed to encourage the baby to turn their head away from the flattened side.
Active repositioning should also be practiced during all awake periods and during sleep.
Repositioning Strategies
- When placing the baby in the crib, alternate the direction the baby faces each night, or change the crib’s orientation in the room so the infant is encouraged to look toward the door or another point of interest.
- During feeding, alternate the arm used to hold the baby.
- When carrying them, use positions like holding them upright or in a carrier to minimize time resting on a flat surface.
- Minimize the time the baby spends in restrictive devices like car seats, swings, or bouncers when not in transit, as these contribute to sustained pressure on the back of the skull.
Recognizing When Medical Intervention is Necessary
While positional plagiocephaly is common and often improves with repositioning, parents should consult a pediatrician if they notice a persistent flat spot or asymmetry by the time the baby is around four months old. The doctor will evaluate the severity of the flattening and rule out a much rarer but more serious condition called craniosynostosis.
Craniosynostosis occurs when one or more of the skull sutures fuse prematurely, which restricts brain growth and requires surgical intervention. Unlike positional plagiocephaly, which is a deformation caused by external pressure, craniosynostosis is a congenital condition that can lead to increased pressure on the brain if untreated. A specialized physical examination is often enough to differentiate the two, though imaging like a CT scan may be used if craniosynostosis is suspected.
If the positional plagiocephaly is moderate to severe and does not improve with consistent repositioning and Tummy Time, a specialist may recommend a cranial orthosis, commonly known as a helmet. This treatment works by applying gentle, persistent pressure to the prominent areas of the head while providing space for the flattened areas to grow into a more rounded shape. Cranial orthosis therapy is typically initiated when the infant is between three and six months old, as this is the period of maximum head growth, and treatment may last for an average of three months.
For infants diagnosed with torticollis, a physical therapy program is often necessary alongside repositioning to stretch the tight neck muscles. Strengthening the neck muscles and improving the baby’s range of motion is a necessary step to allow the infant to naturally turn their head away from the flat spot. A specialist evaluation ensures the appropriate course of action, whether it is conservative management, physical therapy, or cranial orthosis.