I've had TMD on and off for a few years. What is TMD? It's a problem with the jaw joints that can be quite painful at times. It can be caused by stress, and clenching the jaw and grinding one's teeth makes things worse.
My TMD (along with my acne) mostly cleared up when I moved out of my parent's place last month. For the first time in I don't know how long I was using neither muscle relaxant or a splint. The muscle relaxant relaxes a person so that they're less likely to grind their teeth at night, and the splint fits between the teeth to 1) help avoid trouble by keeping the teeth apart, and 2) protect my teeth from myself. Yes, I actually have two small chips in my front tooth, put there by stress last year.
Oh yes, about that splint...I broke my splint early this year, finally saw the TMD doctor about getting it replaced about a month ago, and was finally able to pick up the replacement last Wednesday.
Of course, even though they had taken a mold of my teeth and used that to make a splint special for me, they still had to do some adjustment. And how do they figure out what kind of adjustment is needed? "Here, put this in your mouth, let me put this colored bit of paper between your teeth and your splint, and grind your teeth side to side and forward and back." Which naturally aggravated my TMD.
So I went to the TMD doctor to pick up something that I no longer needed and the visit aggravated my TMD so that I now need the splint that I had not needed before my doctor visit.