Do Dental X-Rays Cause Brain Tumors?

A dentist examining dental x-rays while wearing a face protection maskA new study from Yale Medical School suggests that bitewing X-rays may be dangerous.

A new report, published in the in the April 10 issue of the American Cancer Association journal Cancer, suggests that frequent trips to the dentist’s X-ray chair may lead to an unnecessary risk for a common type of brain tumor. Researchers aren’t ready to suggest that we should skip dental X-rays altogether, but are instead recommending that we get X-rayed less often. Here’s what you need to know:

“These findings should not prevent anyone from going to the dentist,” says lead researcher and neurosurgeon Elizabeth B. Claus, MD, PhD, of Yale University School of Medicine and Boston’s Brigham and Women’s Hospital. “But it appears that a large percentage of patients receive annual X-rays instead of every two to three years, which is the recommendation for healthy adults.”

Dental X-ray, Benign Brain Tumors

While the vast majority of tumors are non-malignant, they often grow to be very large and can cause a wide range of potentially serious symptoms, including vision and hearing loss, frequent headaches, memory loss, and even seizures. They are the most frequently diagnosed brain tumors among adults in the United States, accounting for about a third of all primary brain and central nervous system tumors.

Several small studies have suggested a link between cumulative dental X-ray exposures and brain tumors, but the findings were inconclusive. In the newly published study — the largest ever to examine the question — people who reported having “bitewing” X-rays at least yearly were found to have a 40% to 90% greater risk of tumor growth.

The study shows an association but does not prove a cause-effect relationship.

Annual Dental X-rays Not Recommended

The American Dental Association responded to the study in a written statement, noting that the group has long called on its members to order dental X-rays only when necessary. To minimize radiation exposure, the group recommends using protective aprons and collars and the use the fastest film speeds available or a digital X-ray.

Many oral diseases can’t be detected on the basis of a visual and physical examination alone, and dental X-rays are valuable in providing information about a patient’s oral health such as early-stage cavities, gum diseases, infections or some types of tumors,” the statement reads.

The American Dental Association recommends healthy adults receive routine mouth X-rays every two to three years. Dental X-rays are recommended every one to two years for children and every 1.5 to three years for teens. Children often require more X-rays than adults because of their developing teeth and jaws and increased likelihood for cavities.

The chance of these tumors arising in patients who were X-rayed yearly was low. Nonetheless, dentists and their patients should strongly consider obtaining X-rays less often than yearly unless symptoms suggest the need for imaging.