Dental X-rays Linked to Common Brain Tumor
People who were underwent frequent dental x-rays in the past—when radiation exposure was higher than it is today—have an increased risk of developing intracranial meningioma, according to the results of a study published early online in Cancer.
Meningiomas are very common brain tumors that occur in the membranes that cover and protect the brain and spinal cord (the meninges). Meningiomas usually grow slowly and tend to affect more women than men. Most meningiomas are considered to be benign tumors; however, even benign brain tumors can cause disability and may sometimes be life-threatening.
The primary environmental risk factor for meningioma is ionizing radiation—and the most common artificial source of exposure to such radiation in the U.S. is dental x-rays. In order to examine the link between dental x-rays and meningioma, researches studied data from 1,433 patients (ages 20 to 79) who were diagnosed with the disease between May 2006 and April 2011. They compared these patients to a control group of 1,350 individuals who were similar in age, gender, and state of residence, but had no diagnosis of the disease.
The study examined the frequency of three different types of dental x-rays: bitewing, which is a focused image of one area taken with an x-ray film held in place by a tab between the teeth; panorex, which is taken outside the mouth and shows a panoramic view of the entire mouth; and full-mouth, which includes a number of images of the full mouth.
The results indicated that patients with meningioma were more than twice as likely as controls to report having ever had a bitewing exam. Individuals who reported undergoing yearly (or more frequent) bitewing exams were 1.4 to 1.9 times as likely to develop meningioma as controls. The risk varied depending on the age at the time of the bitewing exam.
Panorex exams were also linked to an increased risk of meningioma. Individuals who underwent panorex exams when they were younger than age 10 had a 4.9 times increased risk of developing the disease. Depending on their age, those who underwent panorex exams on a yearly or more frequent basis were 2.7 to 3.0 times as likely to develop meningioma compared to controls.
The researchers noted that the data was based on individuals who were likely exposed to dental x-rays that contained higher levels of radiation than most dental x-rays today. Still, the results indicate that moderation is important. While many dental x-rays are necessary, it’s important to use careful consideration to determine when and how to use them. The American Dental Association provides guidelines for the use of dental x-rays in healthy individuals: they suggest that children receive 1 x-ray every 1-2 years, teens receive 1 x-ray every 1.5-3 years, and adults receive 1 x-ray every 2-3 years.
As with anything, it’s important to weigh the risks and benefits of dental x-rays on an individual basis. While the results of this study do not prove that the radiation from the x-rays caused the brain tumors, they do suggest that there is a correlation between dental x-rays and meningioma incidence. This could be a modifiable risk factor that many individuals could avoid.
 Claus EB, Calvocoressi L, Bondy ML, et al. Dental x-rays and risk of meningioma. Cancer. Published early online: April 10, 2012.
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