The most prestigious journal on cancer research, aptly named Cancer, has just published a very disturbing article. They review a large scale study (indeed, the largest of it’s kind) dealing with brain tumors and what may cause them. The number one environmental factor associated with this disease happens to be dental x-rays, specifically numerous exposures to bitewing x-rays.
Meningioma, the most common type of brain tumor, occurring in 33% of patients, is the disease dealt with by this study. The study found that patients who regularly received these x-rays were 1.4-1.9 times as likely to develop these tumors. The study was done on people aged 20-79 who were suffering from this ailment, and who were compared with a study group of people who did not suffer from brain tumors. People who have had bitewing x-rays from the time they were under 10 years old were almost 5 times as likely to develop meningioma.
This study is startling for a number of reasons. First of all, it is disturbing because dental x-rays have been refined so much since their inception that many medical professionals have lulled themselves into a false sense of security, or so this study would suggest. The amount of ionizing radiation has been reduced so considerably that dentists are not sure that it can be further lowered. The second concern is that if this data is true, dentists will have to figure out some new technique to see into people’s heads, or worse, forego having x-rays and thus knowledge of how teeth interconnect and lie in the jaw itself. This does not seem likely, for even if ionizing radiation cannot be eliminated altogether the dental x-ray provides such vital information that the risk is well worth it. A surgical wisdom tooth extraction is a routine surgery nowadays, with the help of an x-ray, but just a few short decades ago this was a complication that people used to die from.
The idea is to minimize x-rays, not eliminate them. The study does mention that people who had dental x-rays more frequently than once a year were the most likely to develop these tumors. Another interesting fact to note, is that the study deals with people who developed this tragic illness between May 2006 and April 2011. These patients would be more than likely to have undergone dental x-rays in the past, where ionizing radiation was much stronger, and therefore much more of an issue. How long it takes to develop these tumors is also something that is still being worked out, adding a note of uncertainty in the diagnosis.
The study concludes that dental x-rays for healthy patients at regular intervals is not a factor, only repeated, frequent exposure to ionizing radiation of this type is what causes meningioma. This is somewhat reassuring, knowing that we will not contract meningioma when undergoing a routine, necessary examination, but the possible correlation is still somewhat startling.