It is not strange at all that you ask me, I have actually read too that it may be a connection. I have had one tooth on the left side which got swollen and I did extract it a couple of months later. Could it be a coincidence that it is on the same side as the breast cancer? I also have one tooth which got treatment when I was in highschool I have a filling and back in those days they used something which in time turns your tooth red lol. I do not know if there is any root canal treatment done on my left side teeth though. This is interesting but I wonder if any dentist could work on me now while in chemotheraphy.