I read this article today that suggests a woman got three meningiomas --- a type of brain tumor --- from dental x-rays. The article cites a study from the journal Cancer and states,
… 1,433 people with meningioma were found to be two times more likely to have had a “bitewing” dental X-ray as those without the illness. Those who reported having a panorex scanning dental X-ray (which gives a two-dimensional panoramic view of the mouth) before age 10 were 4.9 times more likely to have meningioma.
In other words, the author uses the study to support the woman’s suggestion that she got three meningiomas from dental x-rays. It’s strange because in the next paragraph, there’s a statistic that women get meningiomas twice as often as men. Does being a woman cause meningioma too? Yikes!
I read the Cancer study which clearly stated that dental x-rays delivered a higher dose of radiation in the past than we do today, and that sometimes the benefits of an x-ray outweigh the risks. It’s also difficult to study this type of phenomenon. First off, the study depended on people’s memory to find out how many dental x-rays they had received over their lifetime. As we all know, sometimes our memories are not the most reliable, especially when it means having to think of events that happened years ago. A better approach would have been to do a chart review and look for documentation of x-rays in each group. That's why we keep charts --- they're more reliable than memories. Unfortunately, this study's design really does open a lot more questions than it answers. At best, it tells us that people who developed meningiomas thought they had more x-rays in the past.
The second half of the article talks about dental CTs. These machines do deliver a higher dose of radiation than a normal x-ray machine. These should be reserved for special cases where the better images are necessary to ensure optimal treatment planning and minimal complications to the patient.
The rest of the article is really just a mishmash of random facts. While the FDA is calling on dentists to “reduce radiation by switching to faster-speed types of X-ray film that require less radiation” most dental offices have already switched over to digital x-rays, which deliver 70-80% less radiation than even the fastest x-ray films. Canadian guidelines would be great; but most newer dental offices are already ahead of the curve on this one. (Dentistry on Main has only ever used digital x-rays.)
It’s also important to remember just how much radiation we’re talking about here. Four bitewing X-rays, which is what many people get in a routine exam, give about .02 millisieverts of radiation, according to the American College of Radiology. That’s about the amount of radiation you get in a week from the sun and other sources. A panoramic dental X-ray, which goes around your head, has about twice that amount of radiation. This gives a complete picture of your mouth that’s usually good for diagnostic purposes for up to 2 years.
Now I’m not advocating for lots of x-rays. Dentists practice a radiation safety principle called ALARA (as low as reasonably achievable) --- to keep the amount of patient radiation exposure at as low a level as reasonably achievable. Routine bitewings and the occasional panoramic x-rays help dentists check bone levels and wisdom teeth, look for fractures or diseased tissues, and catch cavities early before they become painful, and before a root canal is needed. A root canal means a lot of pain, a dead tooth, an expensive dentist’s bill and — that’s right — even more x-rays. And yes, sometimes an x-ray can even catch cancer. In the end, each situation is unique, and it’s important to have a trusting relationship with your dentist to make sure you understand the best treatment options for you.