This is why I routinely refuse dental x-rays unless I have had a toothache or some other symptom indicating a need to have them.
I had large doses of ionizing radiation to my nasal passages as a teenager (before they realized the long-term danger). All of my AN doctors feel strongly this could very likely be the cause of my acoustic neuroma and the regrowth. I am checked regularly for thyroid cancer, as well.
Just so there is no confusion, the amount of gy I had many, many years ago was far greater than any radiation given these days through cyberknife, gamma knife, or FSR for treatment of ANs. It is the amount they used years ago in a much more generalized fashion that caused the problems.
The amount of radiation in today's current dental x-rays is also very small. It's the frequency and accumulation in some people that is a potential problem.
Clarice