A team of researchers has found that people who received frequent dental X-rays in the past have an increased risk of developing meningioma, the most commonly diagnosed primary brain tumor in the United States.

Dental X-ray procedure (thehealthage.com)
The study, published in the journal Cancer, identifies a correlation between past frequent dental X-rays, which are the most common source of exposure to ionizing radiation in the United States, and an increased risk of developing meningioma.
To examine the link between dental X-rays and the risk of developing meningioma, the team studied information from 1,433 patients who were diagnosed with the disease between the ages of ages 20 and 79 years. The researchers also studied information from a control group of 1,350 individuals who had similar characteristics but who had not been diagnosed with a meningioma.
Over a lifetime, patients with meningioma were more than twice as likely as controls to report having ever had a bitewing exam, which uses an X-ray film held in place by a tab between the teeth. Individuals who reported receiving bitewing exams on a yearly or more frequent basis were 1.4 to 1.9 times as likely to develop meningioma as controls.
“The findings suggest that dental X-rays obtained in the past at increased frequently and at a young age, may be associated with increased risk of developing this common type of brain tumor,” said Dr. Elizabeth Claus, a neurosurgeon at Brigham and Women’s Hospital in Boston and the Yale University School of Medicine in New Haven. “This research suggests that although dental X-rays are an important tool in maintaining good oral health, efforts to moderate exposure to this form of imaging may be of benefit to some patients.”
An increased risk of meningioma was also linked with panorex exams (which are taken outside of the mouth and show all of the teeth on one film) taken at a young age or on a yearly or more frequent basis.
“It is important to note that the dental X-rays performed today use a much lower dose of radiation than in the past,” Dr. Claus explained.
“The study presents an ideal opportunity in public health to increase awareness regarding the optimal use of dental X-rays, which unlike many risk factors is modifiable,” Dr. Claus said. “Specifically, the American Dental Association’s guidelines for healthy persons suggest that children receive 1 X-ray every 1-2 years, teens receive 1 X-ray every 1.5-3 years, and adults receive 1 X-ray every 2-3 years. Widespread dissemination of this information allows for increased dialogue between patients and their health care providers.”