MONDAY, April 4 (HealthDay News) -- Cases of "flattened head" in infants and young children appear to be on the rise, a new study of babies in Texas indicates.

Incidences of plagiocephaly -- flattening of the skull in either the front or rear of the head -- have reportedly increased since the American Academy of Pediatrics first recommended in 1992 that infants be put to sleep on their back to reduce the risk of sudden infant death syndrome (SIDS), said the researchers.

The new study appears to confirm that. The researchers reviewed data from the Texas Birth Defects Registry and identified cases of plagiocephaly reported between 1999 and 2007. During that time, the number of cases rose from three to 28.8 per 10,000 live births -- a more than ninefold increase.

The total number of reported cases during the study period was 6,295, and the average number of cases rose by more than 21 percent per year. A large part of the statewide increase occurred in the Dallas/Fort Worth region, where the prevalence of plagiocephaly increased 23.2 times, from 2.6 to 60.5 cases per 10,000 live births.

The increase in cases in Texas was seen in all subgroups, whether based on mother's age, race/ethnicity, education level or on an infant factor such as sex or gestational age.

"A small part of this might have been due to delayed compliance with the American Academy of Pediatrics recommendation for supine infant sleeping and a slight increase in preterm births," wrote a team led by Shane U. Sheu, from the Texas Department of State Health Services.

However, pediatric experts were quick to say that the finding should in no way dissuade parents from protecting their babies from SIDS by placing them to sleep on their backs.

"The recommendation for sleeping the babies on their backs in early infancy still stands, for the tragedy of SIDS does not compare to a flattened occiput [back of head]," said Dr. Peter Richel, chief of pediatrics at Northern Westchester Hospital in Mount Kisco, NY. "So we continue to recommend back sleeping until babies turn over on their own [at approximately 6 months of age]. Also, the incidence of SIDS is greatest in the first six months of life, so this works out well."

Another expert wasn't surprised by the Texas findings, and stressed that skull flattening is usually easily corrected.

"Now that young infants are sleeping on their back, it is not surprising that a small but increased number are exhibiting asymmetries in the skull shape," said Dr. Andrew Adesman, chief, developmental & behavioral pediatrics at the Steven and Alexandra Cohen Children's Medical Center of New York in New Hyde Park, N.Y.

"In many cases, these asymmetries will improve or disappear over time once the child is spending more time sitting up or standing," he added. "Parents who are concerned about their infant's skull shape should discuss this with their pediatrician, who may provide them with some simple suggestions with respect to sleep positioning and crib location. Even children with more severe skull asymmetries can be effectively treated using other approaches such as a 'molding helmet.'"

According to Richel, these helmets are typically advised for babies with "significant" flattening of the skull, and are worn for 4 months on average. "This reshapes the skull as the brain and skull continue to grow," he explained. "At the time the use of the helmet is discontinued, the babies are more mobile and spend less time supine. This is done not for medical reasons, but more for aesthetic reasons, and the helmet use is neither painful nor harmful."

The study appears online and in the August print issue of the journal Archives of Pediatrics & Adolescent Medicine.

More information

The U.S. National Institute of Child Health and Human Development has more about plagiocephaly.