Study: Past dental X-rays linked to common form of brain tumor

A new study suggests that the X-rays you had at the dentist’s office years ago may increase your risk of a brain tumor.

Dental X-rays produce ionizing radiation, which has been linked to non-cancerous brain tumors called meningiomas. Although they’re benign, the tumors can cause seizures, blindness and even, if left untreated, death.

The researchers examined the dental histories of the participants, including those who had the higher-radiation X-rays of the past. The study did not focus on the effect of new lower-radiation methods.

Researchers found that patients with tumors were twice as likely to have had the older technology X-rays. People who had routine X-rays every year before the age of 10 were nearly five times as likely to develop the meningiomas.

"So that's quite significant," said Dr. Keith Black, chairman of the Department of Neurosurgery at Cedars-Sinai Medical Center in Los Angeles. "I think there is an impression in the dental community that dental X-rays carry very little risk."

The study compared nearly 1,500 people diagnosed with brain tumors and a control group of nearly the same size.

Older studies looked at people exposed to high levels of this radiation from atomic bombs or cancer treatments. This new study, led by Yale researchers, is the first to focus on dental X-rays even though they're acknowledged to be the most common type of exposure.

Black regularly declines routine dental X-rays himself. He suggests dental patients with normal exams do the same.

"I don’t believe the risk is worth the routine screening," said Black. "Unfortunately, I think a lot of patients say, 'Yeah, go ahead and do the X-ray,' and a lot of X-rays are performed on a yearly basis on patients when they essentially have a normal exam."

The American Dental Association says X-rays play an important role in identifying cavities, gum disease and infections, nut they recommend X-rays only when necessary for diagnosis and treatment.

They also recommend dentists use protective abdominal shielding and thyroid collars on all patients given X-rays.

The study was published in the April 10 issue of the American Cancer Association journal Cancer and was funded in part by the National Institutes of Health.