I just recently had my fifth root canal and crown done. In doing some online research I came across something called median tooth charts. You find the teeth in question by number, and find body part they are related to. In my case, after looking at when I had a problem with a certain tooth it seemed to be very true. One root canal was during time I had hormone and thyroid problems. Another two was related to intestinal problems after back surgery. (They went through my ab to do the spine surgery, and afterward I had gas, bowel and incontinence issues). It really blew my mind to think of it. Another reason to keep up on the body health as well as teeth!