Non-cancerous Brain Tumors Linked to Frequent Dental X-rays

People who received frequent dental X-rays in the past have an increased risk of developing a meningioma, the most common and potentially debilitating type of non-cancerous brain tumor, a new study led by the Yale School of Public Health has found.

The study found that individuals receiving bitewing exams (which use X-ray film held in place by a tab between the teeth) on a yearly or more frequent basis were approximately 50 percent more likely to develop a meningioma than their peers in the control group.

The researchers also found a link between meningioma risk and the panoramic dental exam (which uses an X-ray outside of the mouth to develop a single image of all of the teeth). Individuals younger than 10 years old who received this exam in the past had a nearly five times greater risk of developing meningioma, while those who received it on a yearly or more frequent basis were up to three times more likely to develop a tumor.

The researchers analyzed data from 1,433 patients who were diagnosed with the disease and were residents of Connecticut, Massachusetts, North Carolina, California and Texas. The investigators also included information from a control group of 1,350 individuals with similar characteristics who did not have the tumor. The mean age was just over 57 years for both groups.

While today’s patients are exposed to lower X-ray doses than in the past, the American Dental Association (ADA) stresses the need for dentists to examine the risks and benefits of dental X-rays and has confirmed that there is little evidence to support the use of dental X-rays of all teeth in patients who are not experiencing symptoms.

“The study highlights the need for increasing awareness regarding the optimal use of dental X-rays, which unlike many risk factors is modifiable,” said lead author Elizabeth Claus, a professor at Yale and a neurosurgeon at Brigham and Women’s Hospital in Boston.

The American Dental Association’s guidelines for healthy persons suggest that children receive one X-ray every one to two years; teenagers every one and a half to three years and adults every two to three years, Claus said.

Meningiomas develop in a membrane that envelops the brain and the central nervous system known as the meninges. These tumors can grow undetected for years and eventually reach the size of a baseball or larger. While they are not cancerous, they can cause debilitating side effects such as headaches, vision problems, and loss of speech and motor control. Women develop the tumors more often than men.

The study is published online in Cancer, a journal of the American Cancer Society. Other authors are Joseph Wiemels and Margaret Wrensch of the University of California at San Francisco, Joellen Schildkraut of Duke University, Lisa Calvocoressi at the Yale School of Public Health and Melissa Bondy of the Baylor College of Medicine.