If you get a group of dentists in a room, you will hear all different theories depending on their educational background. There are so many theories but no conclusive evidence of the causation. Stress, habit, teeth not fitting together properly, neurological diseases and many more theories float around our community of dentists.
The result of the nighttime clenching and grinding can be severe and I have seen the spectrum of destruction from broken teeth, to severe headaches, to jaw joint pain and dysfunction. Some people suffer terribly with pain while others with the exact same condition go through life with not a complaint!
The good news is that, despite the confusion, there is a lot of solid science to help most patients get relief.
The approach is to analyze a patient’s bite and figure out the possible solutions. It may be that the bite scheme is off and needs to be re-configured. Or it may be that the patient needs a nighttime appliance to help control the grinding and resulting muscle tension.
I myself wear one every night for clenching and grinding. In fact I had broken a tooth before I started wearing my night guard.