Recently an article titled “Dental X-Rays and Risk of Meningioma” was published in the April 2012 issue of the journal Cancer. The article describes a recent study that associates yearly or more frequent dental X-rays to an increased risk of developing meningioma, the most commonly diagnosed brain tumor.
The ADA (American Dental Association) has reviewed the study and notes the following weaknesses in the study design and interpretation that affect the outcome of the study.
- The results of this study rely on the individuals’ memories of having dental X-rays taken years earlier (10 to 69 years earlier). Studies have shown that the ability to recall information is often imperfect. In some cases, the patients were asked to remember the type and frequency of x-rays taken when they were 10 or younger. Therefore, the results of studies that use this design can be unreliable because they are affected by what scientists call “recall bias.”
- The study acknowledges that some of the subjects received dental x-rays decades ago when radiation exposure was greater. Advancements in technology have successfully reduced radiation from dental X-rays to very low levels. In fact, they are among the lowest levels of all medical tests. This means that radiation levels were likely higher for the study participants than they are for patients today. As a point of comparison, the amount of radiation you’ll get from one bitewing X-ray is the same as from one hour flying in an airplane.
- The study was also observational in nature, meaning it can show an association but not a cause-and-effect relationship between dental X-rays and meningioma.
- The results of the study did not appear to be dose-related as would be expected.
The good thing about the study is that it raises awareness that getting X-rays should not be taken lightly and should be done only when necessary. Sunningdale Dental Centre has always followed the guidelines to prescribe dental x-rays only when necessary, and on an individual case by case basis.
There are many oral diseases that can not be detected with just a visual or physical exam. Dental X-rays can help our dentists find cavities between your teeth or under fillings, gum and bone diseases, infection under your gums, and some types of tumors. X-rays help catch and treat these hidden problems at an early stage before they pose a greater risk to your health and result in more extensive and expensive dental treatment.
What precautions do dentists take to reduce the radiation risks of dental X-rays?
- Leaded aprons are used to protect the body and, whenever possible, thyroid collars around the neck to protect the thyroid gland. Both of these devices limit radiation exposure.
- New technologies, like faster speed films and digital imaging, reduce exposure to radiation significantly.
Further Information & FAQ’s
Canadian Dental Association – Are X-rays Safe?
American Dental Association:
- How do dental X-rays work?
- How often should radiographs be taken?
- What are the benefits of a dental radiograph examination?
- How do dental X-rays compare to other sources of radiation?
- What if I’m pregnant and need a dental radiograph examination?