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This molding helmet, for infants older than 4 months, provides a brace to redirect cranial growth to the flattened areas. |
Plagiocephaly and related cranial deformities
Since the American Academy of Pediatrics launched its “Back to Sleep” campaign in 1992, parents have laid their babies to sleep on their backs in an effort to prevent sudden infant death syndrome (SIDS). This recommendation has been widely followed but has lead to an increase in deformational cranial flattening. “The rise in plagiocephaly has spawned a lot of concern on the part of pediatricians and parents,” says Gary Rogers, MD, JD, MBA, MPH, of the Department of Pediatric Plastic Surgery at Children’s Hospital Boston. Fortunately, the implications of this process are relatively benign.
Plagiocephaly affects an estimated 20 to 25 percent of infants who sleep on their backs. The flattening occurs almost exclusively in infants who have restricted or decreased head mobility, especially during the first several months of life. The most common risk factor is congenital muscular torticollis (CMT), a neck muscle imbalance caused by constraint of fetal head movement while in the womb. CMT can be precipitated by any situation that limits infant mobility; common associations include multiple-birth gestation, low volume of amniotic fluid, males (larger on average than females) and first-born infants. Other risk factors are prematurity and developmental delay.
Although the flattened appearance of an infant’s head can be startling, there is no convincing scientific evidence to suggest that plagiocephaly is harmful to brain development, vision, temporomandibular joint function or hearing, Dr. Rogers says. The only lasting effect is on the shape of the head, which is both preventable and treatable.
Any baby’s skull can start to flatten if, during its rapid expansion, it meets resistance against a flat resting surface. This process takes time; parents usually start to notice the shape change of a newborn’s head between 6 to 8 weeks old. Contrary to what past researchers have hypothesized, a baby’s skull does not flatten because it is naturally soft.
Plagiocephaly – flattening appearance on one side of the head, which may result in facial asymmetry; most often the result of CMT
Brachycephaly – symmetrical flattening of the occiput; babies have little or no rounding on the back of the head and appear to have a disproportionately wide head
Asymmetric brachycephaly – elements of both brachycephaly and plagiocephaly
Scaphocephaly – a flattening of one side of the skull, accompanied by compensatory growth in the front and back of the skull
Identifying babies who are most at risk can be as simple as asking parents, “Does your baby have a preferred head position while lying down?” The best time to have this conversation is at a newborn’s first well-baby visit, Dr. Rogers says. A preferred head position can be a sign of CMT, which may be under-diagnosed in light of the fact that it is hard to spot before a baby begins to sit up. Because torticollis typically resolves with increasing tone and infant mobility, a classic head tilt may not always be obvious.
To treat or not to treat?
Plagiocephaly is primarily an aesthetic problem. While talking with parents, it’s important to remind them that the appearance of skull flattening can change, and as a child grows, the flattening can become less noticeable. Additionally, as the child grows taller and the vantage of the posterior cranium changes from top-down to posterior-side, the flattening will look less pronounced. If parents decide to treat their baby, or a doctor feels this condition to be outside her realm of expertise, she should refer.
There is some evidence to suggest that physical therapy and repositioning of a baby’s head may improve torticollis in infants younger than 4 months. But while this can prevent further skull flattening, it can’t fix flattening that has already occurred, Dr. Rogers says. The best way to prevent skull flattening in a baby younger than 4 months is to have the baby’s head rest on a surface that is concave rather than flat, allowing contact pressure to spread more evenly on the skull. There are orthotic devices to allow this, but physicians should tell parents that many of these devices do not adjust over time as a baby grows. Also, even though some devices are approved by the FDA, this doesn’t mean they are safe or effective.
At Children’s, doctors developed a molding cup that includes removable liners that increase in size to accommodate a growing baby. This is the only orthotic device clinically proven effective in preventing plagiocephaly in a controlled study of infants younger than 3 months. It is generally ineffective after 4 months of age due to increased infant mobility.
In infants with clinical flattening who are older than 4 months, parents may opt to treat their baby with a molding helmet, which provide a brace to redirect cranial growth.
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