As if you needed another reason to hate the dentist. According to a recent study, dental x-rays are associated with an increased risk of the most common type of primary brain tumors, called meningiomas. This is a very sobering possibility and the study deserves a serious discussion. I admit my bias in analyzing this study. I recommend and take dental x-rays every day. But the study has some weaknesses that need to be recognized and targeted for further research.
The study compared a group of 1433 patients who had been diagnosed with meningioma to a group of 1350 patients who self-reported that they did not have a meningioma. This self-reporting is a problem inherent to case control studies, but especially with meningiomas, which are often asymptomatic. Previous studies have shown that asymptomatic meningiomas are almost 3 times more common than symptomatic. It’s possible that patients in the control group had meningiomas and did not know it, which would alter the results of the study.
Both groups were also asked to self-report their history of dental x-rays. Patients who had meningiomas were more likely to reports having received bitewing dental x-rays, panoramic x-rays before the age of 10, or yearly panoramic x-rays. I personally cannot remember how many and what type of x-rays I have received over the past 5 years, much less the last 20. Patient recall of x-ray history is often found to be incorrect when previous dentists are consulted. This type of study is also prone to what researchers refer to as “recall bias” where people with the disease are likely to look for a cause and over-report their history of something like dental x-rays.
Dental x-ray technology has changed significantly over the last 20 years with digital x-rays becoming much more commonplace. Digital intraoral x-rays give anywhere from 40-75% reduction in radiation dosage compared to intraoral films. In my office, we are able to reduce exposure time by about 66% using digital x-rays. The effects of x-ray radiation are dose dependent. Dosage was so neglected by the study that it actually showed that a single bitewing x-ray has a 50-100% greater risk than a full mouth series of 20 x-rays.
Please speak to your dentist about your need for dental x-rays. Most likely, he is following the recommendations of the American Dental Association for radiographic examinations, and is working to keep your radiation dosage As Low As Reasonably Achievable (ALARA). X-rays enable us to find problems earlier when they are much easier and cheaper to fix. Avoiding x-rays, when they are recommended appropriately will increase the likelihood that you will lose teeth early and spend more money at the dentist.
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