Helmet therapy, a common treatment to relieve infant skull deformation, appears to be as effective as not doing anything at all, according to a new study.

Researchers at the University of Twente in the Netherlands found that there was no significant difference in improvement of the shape of the skull between children who were administered helmet therapy and children who received no treatment at all.

The study, which was published Thursday, May 1, on BMJ is the first single-blind, randomized trial that aims to examine the effectiveness of helmet therapy on babies afflicted with positional skull deformation, also known as plagiocephaly or flat head syndrome.

The researchers identified 84 healthy babies with mild to moderate plagiocephaly, where one side of the head becomes flattened and, in severe cases, the ears are misaligned, or brachycephaly, where the back of the skull is flattened and the front may protrude outwards.

They randomly selected 42 babies who were to wear a helmet for 23 hours a day for the next six months. The helmets were custom-made for each baby to adhere closely to the infant's head, while leaving a bit of room for the baby's skull to expand as the the child grows. Manufacturers of these helmets claim the helmets will allow the baby's skull to round out into the space found inside the helmet.

The researchers provided no active treatment for the other half and instructed their parents to allow the natural course of the condition to pan out over the duration of the study.

Two years after treatment, the researchers measured the babies' heads and found no meaningful difference in the degree of improvement between the babies who received helmet therapy and those who didn't. About one-fourth of babies in both groups showed full recovery by the time they were two years old. 25.6% of those in the helmet therapy group recovered from skull deformation, compared to the 22.5% in the no-treatment group.

Parents of babies in the helmet group also reported negative side effects, including skin irritation, which was found in 96% of babies, as well as unpleasant smell, sweating, pain and parents feeling hindered from cuddling their babies.

Approximately one out of five babies have misshapen skulls due to increased pressure on one part of the head. For example, babies who spend so much time lying on their backs may develop a flat spot on the back of their heads.

"Based on the equal effectiveness of helmet therapy and skull deformation following its natural course, high prevalence of side effects, and high costs associated with helmet therapy, we discourage the use of a helmet as a standard treatment for healthy infants with moderate to severe skull deformation," the authors wrote.

Custom helmets for treating flat head syndrome cost somewhere between $1,300 and $3,000.

Manufacturers have come out questioning the new findings. According to Orthomerica spokesperson William Gustavson, it is "alarming" that nearly three-quarters of the babies given helmet therapy had the helmets moving around on their heads. The American Orthotic and Prosthetic Association says the value of the study hinges upon the helmets' ability to stay fit and close over the infants' heads.

Tim Littlefield, a representative of Cranial Technologies, uses this as the basis for his claim that the study is "inherently flawed."