I have always had a jaw that pops. I can pop it on will the way people pop their knuckles. I try not to do that, but it's become something of a bad habit. It didn't used to lock.. but about a year or so ago, I started having problems with it locking. These problems make it hard to chew, talk, or just open my mouth. It locks on the right side more than the left. The only thing that fixes it... is pushing at it until it pops again. Which I know I should not do, but I cannot afford to have it looked it. I don't know if it is related, but I have a bad bite (an overbite) that I have never been able to afford to have corrected. I, also, have very crooked teeth. If you can afford to have it looked at, I highly recommend doing so. Mine didn't hurt - in the beginning. It definitely does from time to time now. So much sometimes that it makes me want to cry. A mouthpiece might benefit you.