April 10, 2012
Frequent Dental X-rays May Be Linked To Brain Tumors
A new study has shown a link between frequent dental X-rays and an increased risk of developing non-cancerous brain tumors. Researchers are using this study as a reminder of the dangers of frequent dental X-rays.
Rather than suggesting patients eschew these X-rays, these researchers are recommending their new findings become part of the conversation the patient has with their doctor. In fact, the American Dental Association´s (ADA) guidelines still recommend healthy patients, free of other health risks, get “bitewing” X-rays once every one to three years, depending on their age.
Dr. Elizabeth Claus, a professor of public health at the Yale University School of Public Health and a neurosurgeon at Brigham and Women´s Hospital, led the study which was published Tuesday in the journal Cancer.
“The broader public health message is that probably the increase in risk to a given individual, given the current dose [of radiation exposure] is low," said Claus, speaking with the Boston Globe.
“But you could say, gee, if this is a primary exposure in the US and we can lessen the exposure," this is an issue worth considering Claus said.
To find these results, researchers surveyed more than 1,400 patients who had meningiomas (the non-cancerous brain tumors) and compared them with more than 1,300 patients who did not have the tumors. The researchers then asked these patients about their X-ray history. According to these surveys, those who had the bitewing X-rays were twice as likely to develop the meningiomas than those who did not have the X-rays. Those patients who had at least one X-ray a year had an increased risk for these tumors, despite their age.
This study is seen to have many limitations due to the way it was conducted, however. For instance, the study does not show how much a single X-ray increases a person´s risk for the tumors. Furthermore, the surveys asked the patients to rely on their memory of the X-ray history, rather than look at actual patient records. Therefore, patients could have over-or under-estimated the amount of X-rays they had received.
Dr. Matthew Messina, a consumer advisor for the ADA says the study has credit and merit, as reducing the amount of radiation used by X-ray machines is always a priority. He did mention, however, these conclusions might be given too much weight, despite its shortcomings.
Calling on personal experience from his private practice, Dr. Messina said patients often thought their last X-ray was much more recent than it actually was, a fact confirmed once their previous doctor had been contacted. Therefore, he believes patients who have the brain tumors may be ready to wrongly blame the X-rays.
“While the study is something that obviously we want to take seriously, I think it needs follow-up," Messina said.
Meanwhile, Dr. Anita Gohel, director of radiology at Boston University´s Henry M. Goldman School of Dental Medicine, said students are taught to do a detailed visual and clinical exam first before breaking out the X-ray, therefore exposing patients to the lowest amount of radiation possible. Speaking with the Boston Globe, Gohel said, “X-rays do cause harm, we all know that, so the benefit should always outweigh the risk, and that´s what we teach dental students."