sounds like to could be TMJ, which is stress-induced. Not sure of the treatment for that, but any reputable dentist could possibly help. I also get this when I'm seriously stressed. When the stress relaxes, so does my jaw. It is painful, though. Hope you feel better soon.
Current dx: Rheumatoid Arthritis
Suspected dx: UCTD/Early Lupus
Current Meds: Enbrel, Plaquenil, Methotrexate, nexium, tramadol, nasonex,Tylenol PM
Past Meds: Relafen, Vioxx, Mobic, Voltaren, Sulfasalazine, Entocort, Prednisone, Humira, Reglan, zyrtec, zegerid, aciphex