that joint is very complicated -- the only one that has to move in four, not 2 directions, and dislocation and wear type arthritis are the norm.
Even if you are teeth grinding or jaw cleaching in your sleep, which can cause progressive damage, only 5% gone on to agonizing pain.
Just make sure that you have a dentist check that you have no signs of grinding or clenching. If you do, don't assume a biteguard will do anything more than protect your teeth from being eventaully destroyed by chronic pressure. Study up on physical therapy (see sticky posts), botox, etc., if it gets chronic enough to start damaging the joint, jaw, or teeth permanently.