Some months have passed since the topic of a link between dental X-rays and brain tumors made waves in national and international media. The flurry of news stories and blogs, press releases and tweets died down after just a few days, and the details of the x-ray/tumor link were mostly buried under hurried summaries that focused on the most sensational angle.
Now that the air has cleared a bit, we thought we’d take a look at the issue again and try to clarify the key points for today’s consumers.
What the study actually said
In April, 2012, the study, “Dental X-rays and Risk of Meningioma,” appeared in a peer-reviewed journal, Cancer, which is published by the American Cancer Society. The research was led by researchers from Yale University School of Medicine. They concluded the following:
“Exposure to some dental X-rays performed in the past, when radiation exposure was greater than in the current era, appears to be associated with an increased risk of intracranial meningioma. As with all sources of artificial ionizing radiation, considered use of this modifiable risk factor may be of benefit to patients.”[i]
Not quite the same as what made it into the headlines. The caveat, “X-rays performed in the past, when radiation exposure was greater than in the current era,” sort of got lost in the shuffle.
Instead, “increased risk of intracranial meningioma” stole the show. Not so hard to do with descriptions reported in the media that included details about typical tumor sizes (“can reach sizes larger than a baseball”) their effects (“often benign, but can be debilitating”) and the populations affected (“commonly found in people 40 – 70 years old and mostly women”).
In the end, the authors’ reasoned recommendation of “considered use” simply got railroaded by fear-inducing headlines.
Responses to the study
Almost immediately, perhaps to help calm the media frenzy, some dental experts issued a statement that questioned the study’s findings. They were concerned, they said, because the association of X-rays with brain tumors in the study had been based on anecdotal evidence.[ii]
In Yale’s population-based, case-control study, people with intracranial meningiomas were asked to recall how often they had received dental X-rays at various stages of their lives, including whether the type of X-ray used was a bitewing, full-mouth, or panoramic variety.
In part, the dentists’ response read as follows:
“Taken together, the methodological weaknesses of this study put the validity of any relationship between dental radiographs and meningioma into serious question. Oral and maxillofacial radiography is an important diagnostic tool in the armamentarium of the dentist, and the American Academy of Oral and Maxillofacial Radiology continues to endorse its careful and judicious use in dentistry.”[iii]
Oral and maxillofacial radiography is an important diagnostic tool…
The study reported in the journal Cancer may not sound like the type of strictly controlled objective observation most people would commonly associate with scientific investigations. However, in this case the approach was deemed to be pragmatic, in that it allowed the scientists to explore variables that, unfortunately, simply weren’t foreseen 50 years ago.
While what they reported has some practical relevance for people who were having X-rays in the 1960s, the typical dose of radiation a patient received from a single exposure was significantly higher at that time than it is today.
What’s best for consumers?
Ultimately, at a higher level, the conversation was about weighing the risks and benefits to patients of using radiography. And here – theoretically at least, there is clear agreement. When it comes to dental radiography, the study’s recommendation aligns, after all, with those of the ADA.
Everyone agrees: X-rays should only be used in specific, carefully considered situations.
The American Dental Association publishes strict guidelines for using X-rays[iv] to help ensure this is always the case. Consumers should therefore never allow a sensationalized fear of brain tumors the size of baseballs to prevent them from getting appropriate dental care when needed.
…never allow fear to prevent getting appropriate dental care when needed.
So if your dentist suggests that you have X-rays, it’s fine to ask whether there are any reasonable alternatives. And if X-rays are, in fact, deemed necessary, you can also expect to hear some very carefully reasoned justifications.
Do you worry about dental X-rays and brain tumors? Did this blog help you understand the risk? Share your thoughts in the comment section below.
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[i] Claus, E. B., Calvocoressi, L., Bondy, M. L., Schildkraut, J. M., Wiemels, J. L. and Wrensch, M. (2012), Dental x-rays and risk of meningioma. Cancer, 118: 4530–4537. doi: 10.1002/cncr.26625, http://onlinelibrary.wiley.com/doi/10.1002/cncr.26625/abstract
[iii] AAOMR Response to Recent Study on Dental X-ray Risks, http://c.ymcdn.com/sites/www.aaomr.org/resource/resmgr/docs/aaomr_response_to_study2.pdf