I wanted to let you know that the first sign my son and I had that we had TMJ was our top teeth hitting on top of our bottom teeth. This means that the bottom jaw is trying to come forward from a trapped position. If you have had orthodontics than I would say you have the same problem my son and I have, that the orthodontist moved your lower jaw back and the brought you top teeth in to hold this force position which caused your TMJ. If you haven't had orthodontics it still supports that you lower jaw is trapped posteriorly and is trying to come forward to relieve your TMJ and correct your lower jaw position. Either way it's not got because it will cause wear and damage to your teeth and gums and it needs to be addressed as soon as possible. My sons teeth started doing this and within 2 months he had 2 deep groves worn in his front teeth. The hard contact can also cause root resorption, it needs to be addressed as soon as possible. Also it's a major sign that your jaw joints are damaged and they will continue to suffer damage unless you get the proper treatment which would begin with a proper fitting splint to protect your teeth and jaw joints. If the doctor you seeing won't address this problem, find one who will because it will only get worse.