Last year I had a bad root canal done in a Third World country – and then again on the same molar. The pain never completely went away for a year until I could get to my USA dentist. I had no idea that the horrific pain in my knees that began a couple of months after the bad root canal and my tooth pain could be connected because the MRI on my knees showed I needed knee replacement. However, when I had the tooth pulled, my knee pain went away almost completely…..within a couple of days! I was shocked -- and enormously relieved. I will definitely hold off on any knee surgery now. This is the second time tooth problems have been connected to pain elsewhere in my body. About 20 years ago, the bottoms of my feet hurt so badly I had to teach sitting down and could barely make it from my car to the classroom. The university sports med. dr. took x-rays but could not find ANY cause of my debilitating foot pain. Then I happened to have a root canal on a tooth that had NOT been bothering me, but that the dentist had said I needed a root canal for about a year. Within 24 hrs of the root canal being done, the pain in my feet went away COMPLETELY! And never returned. Definitely very, VERY weird!