Re: Trying to determine the cause...
It is very difficult to determine the cause of TMJ. It is different for everyone. If your bite is off, then that's the problem, and if not corrected, it can get worse. I went to 2 orthos and a head & neck surgeon when I first got TMJ and they all told me that the problem wasn't my bite. It was muscular and I was clenching/bruxing unconsciously at night. So... I took muscle relaxants, bought hot pads for my jaw, did acupuncture, did physical therapy, got botox injections, did massage therapy, and wore a hard acrylic splint at night, all in the hopes that my masseter muscles would eventually relax... They did not.
My bite has gotten progressively worse with time, and now the orthos are saying it's my bite. Oh... and my facial pain switches sides as well. Botox works for the pain. The pain you have is caused by the tightness of your muscles. Botox essentially causes your muscles to atrophy (relaxes them). But it is just for the pain. If your problem is truly muscular, 2 rounds of botox should do it. But, if it is in fact your bite, no amount of pain pills, tranquilizers or botox will take care of the problem permanently... only orthotics.