5 months ago I had 2 back molars removed due to a crack and infection. The 3rd tooth right next to these (premolar?) then had a root canal and crown. The extraction of the 2 teeth was not easy as both were attached to the jaw bone. In the last couple of weeks, the root canalled tooth is a little tender to side pressure only when pressed (not pressure at the top, no sensitivity to hot or cold or general ache) and I have a mild ache in the jaw were the 2 teeth were removed and under my ear. I've been to both my dentist and oral/maxfax suregon (but not my endodontist who did the root canal yet) and neither can see anything wrong with the root canal tooth or in the area where the teeth were removed. My oral/maxfax surgeon has diagnosed TMJ as my jaw on the opposite side pops out of place at night and sometimes locks so I cant open it fully. He thinks the pressure pain in the root canal tooth could be due to grinding my teeth and 'Im getting a mouthguard. My question is, could the grinding be hurting the root canal tooth (the bite is fine) or is the root canal failing? I know its hard to answer without x-rays.