Hi Bryanna, I am having the same problem. A Fistual on my gums right under my second molar that has gone through a rootcanal with a new crown on top.

The fistula did not develop until maybe 2 years after my the rootcanal. The dentist says it might be from microfractures from the tooth. I do grind my teeth at night. The fistula comes and goes but more recently it has caused tremendous pain. I have scheduled an appointment with a specialist this week. Does a fistula from tooth fractures also require extraction? What do i do with a missing molar? i am only 29. Thank you for all the information that you have posted.