Last year, I was at a routine dental visit when my dentist said that it's time to get an X-ray. Remembering that I had an X-ray in my last visit 6 months ago, I asked why? He said that my insurance allows a panorex scan every few years and that I am now eligible for one again. Upset that the insurance company gets to decide when I need an X-ray. I asked why I need a panorex when I just had regular X-rays last time. He said that it helps diagnosed other abnormalities not picked up on regular X-rays. When I asked what other abnormalities, he said, "Oh, lots. For example, we could find a bone tumor. We don't want to miss that." Knowing that bone tumors are pretty rare, especially in the face, I declined.
I am glad I did. This study finds a link between dental X-rays and meningiomas (a benign, but sometime hard to treat type of brain tumor). It's a case-control study, so not the strongest type of study, but it's not surprising. X-rays are radiation. Radiation damages DNA, which can lead to cancer. X-rays as a screening test carry a risk. A pretty small risk, but a risk nonetheless. So, if X-rays are being used as a screening test in asymptomatic individuals, the disease they detect should be 1) common and 2) easier to treat if caught earlier. Breast cancer is an example of a disease that fits this descriptions, and breast X-rays (mammograms) are worth using as a screening tool. Maxillary or mandibular bone cancers are rare. Very rare. The cost and risks of X-rays do not justify their use as a screening tool. Just because the insurance company allows something, it doesn't mean that it should be used.
Dentists are well aware of the fact that their frequent X-rays are unnecessary in the vast majority of their patients. Their patients don't know that. It's an easy way to make money and it's criminal that it is common practice. So, unless you've got symptoms, it's not worth getting frequent dental X-rays.