People who often received dental X-rays in the past have an increased risk of developing a meningioma, a non-cancerous brain tumor, U.S. researchers said. Elizabeth Claus, a professor at Yale School of Public Healthand a neurosurgeon at Brigham and Women\'s Hospital in Boston, said the study she led found people receiving bitewing exams -- X-ray film held in place by a tab between the teeth -- on a yearly basis were approximately 50 percent more likely to develop a meningioma than their peers in the control group. Claus and colleagues 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 age 57 for both groups. The study published online ahead of the print edition of Cancer 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 age 10, 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 study said.