On teeth removal it often seems like You're damned if you do, and damned if you don't. I was so relived when I got the all clear to keep my teeth prior to radiation, but now 8 months after TX, I have had one root canal on a lower molar and two crowns on the upper molars. Blue Cross/Blue shield while great on paying the quarter of a million for rad/chemo paid a grand total of $100 for all of that. all these teeth were in the radiation field (7200 cGY) Worse, yesterday the left wisdom tooth was diagnosed as not only cracked but with root damage and infection. Endo thought extraction but periodontist thinks too much risk of ORN (osteradionecrosis)even with HBO (Hyperbolic Oxygen Therapy). Anyway, please don't fault yourself or rethink those past decisions. No matter what you had chosen, the current "cure" for this cancer would give you problems. As bad as things feel now, if you had ORN, it'd be worse. I wish you only the best in the future.
tom