Frequent Dental X-Rays Linked to Increased Brain Tumor Risk

Ionizing radiation from frequent dental X-rays may increase the risk of meningioma, the most commonly diagnosed primary brain tumor in the United States, researchers said. Their findings were published in the journal Cancer.

Researchers studied information obtained from 1,433 patients between the ages of 20 and 79 who were diagnosed with meningioma between May 1, 2006 and April 28, 2011, and a control group of 1,350 individuals. They found that patients with meningioma were more than twice as likely as controls to have had a bitewing exam, which uses an X-ray film held in place by a tab between the teeth.

Patients who had yearly or more frequent bitewing exams were 1.4 to 1.9 times more likely to develop the brain tumor than were the controls, although the age at which the exams were done did have an effect on risk.

Panorex exams - those that are taken from outside the mouth to allow dentists to see all the teeth at once - carried an even greater risk for meningioma than the bitewings, which increased with the frequency and age of the patient when the tests were done. If the individuals were younger than 10 years old, they had a 4.9 times higher risk of developing meningioma, while those who had the X-rays done annually or more often were 2.7 to 3.0 times (depending on age) more likely to develop the tumor than were the controls.

Dental X-rays are the most common source of ionizing radiation among Americans, although today’s patients are exposed to lower levels than in the past. While dental X-rays are mostly taken for granted, this type of information may help the public discuss the risks and benefits of dental X-rays in people who have no symptoms of dental problems, researchers said.

Guidelines from the American Dental Association suggest that healthy children receive one X-ray every one to two years, healthy teens receive one X-ray every 1.5 to three years, and healthy adults receive one X-ray every two to three years, said Elizabeth Claus, MD, PhD, of the Yale University School of in New Haven, Conn., and Brigham and Women’s Hospital, in Boston, Mass.

“Widespread dissemination of this information allows for increased dialogue between patients and their healthcare providers,” she said.