Thyroid Cancer Prevention?

     I was talking to my grandmother recently and she was reading one of those forwarding e-mails, I don't know how true it is, but it sounds plausible. The info originated on Dr. Oz or some such television show.
     When you go to the dentist and get X-rays most people don't realize that your thyroid is right below your jaw. We're told that constant exposure to radiation can cause cancer and it makes sense that regular exposure to radiation at the dentist (or during mammograms for women) can increase your risk, or cause cancer. But there is a guard to protect you; a flap on the apron at the dentist's office and a "thyroid guard" to wear during mammograms are available, but most people don't know about it or don't use it.
     Why don't we know about it? I don't know, maybe it's just a lack of information. If so, let's spread the word.

Just a thought....
Stephie