Frequent Dental X-rays Linked to Increased Brain Tumor Risk

A new study has found that exposure to radiation from frequent dental X-rays is linked to increased risks for developing brain tumors. According to the study conducted by doctors and scientists from Yale, Harvard, and a number of other respected institutions, the risk is as much as two-fold, said MSNBC. The study appears in the journal, Cancer, a scientific publication of the American Cancer Society.

Despite the findings, the researchers caution against panicking. “Our take home message is don’t panic. Don’t stop going to the dentist,” lead author, Dr. Elizabeth Claus, a neurological surgeon at Brigham and Women’s Hospital in Boston and the Yale School of Public Health, told MSNBC. Claus suggested patients “should have a conversation with their dentist” about the need to balance X-ray use and teeth health.

The tumor studied, meningioma, is typically nonmalignant, but can grow and can cause significant problems for some. According to MSNBC, doctors diagnose some 5,000 cases annually in the United States; women are diagnosed about three times more often than men.

The case control study involved interviews with 1,433 people diagnosed with meningioma who were compared with 1,350 people without that diagnosis. Both groups were matched for age, gender, race, income, residence location, said MSNBC. Some dental records were reviewed; however, dental history, as far back as childhood, was discussed with the participants, who were an average age of 57. Increased tumor risks were seen in people who received bitewing exams, an X-ray in which the film is held by a tab between the teeth. Bitewing X-rays are traditionally performed one-to-two times annually, said MSNBC. Reuters said that the study also looked at full mouth X-rays.

Increased risks were also seen from the panorex dental exam, in which an external X-ray retrieves an image of all of the teeth. Adults who received this type panorex X-rays when under the age of 10, experienced a five times increased risk of developing meningioma, said MSNBC.

Reuters noted that the findings do not prove a direct tumor-radiation risk and the risk is based on people who were probably exposed to increased radiation levels than are seen in current X-rays. “It’s likely that the exposure association we’re seeing here is past exposure, and past exposure levels were much higher,” Claus told Reuters. According to the researchers, dental X-rays are the most common source of ionizing radiation exposure, which has long been linked to meningiomas, said Reuters.

Dr. Otis W. Brawley, scientific director of the American Cancer Society, told MSNBC that, “the strongest thing you can say about this study is that there is a suggestion of a link between dental X-rays and meningioma.”

2006 American Dental Association guidelines state that X-rays should not be used for “detecting disease before clinical examination.” Should a dentist find that X-rays are warranted, they should be administrated with “the ALARA Principle (As Low as Reasonably Achievable) to minimize the patient’s exposure,” according to the guidelines, wrote MSNBC. “The ADA’s long-standing position is that dentists should order dental X-rays for patients only when necessary for diagnosis and treatment. Since 1989, the ADA has published recommendations to help dentists ensure that radiation exposure is as low as reasonably achievable,” it said.

The researchers point out that, “while dental X-rays are an important tool in well selected patients, efforts to moderate exposure to (ionizing radiation) to the head is likely to be of benefit to patients and health care providers alike,” wrote Reuters.