TMD: temporomandibular disorder
Causes of TMD
TMD is characterized by either popping or clicking of the jaw upon opening or closing, or by pain. Like tension headache, it is believed to be caused by excessive tightening of the muscles, in this case in the jaw.
Current Research
Research on the use of biofeedback to treat TMD has been similar to the previously mentioned work on tension headache, though a little less extensive. Although patients do respond positively to EMG biofeedback, they also improve after nearly any treatment possible, including medications, oral appliances, exercises, counseling, as well as placebo treatments; 92% of patients in one study experienced little symptomology after any of these treatments (Turk, 1996). Turk explains that this is due to the warm, encouraging attitude of the therapist. Thus, for TMD chronic pain as well as for tension headaches, nonphysiological factors hold a great deal of importance in symptoms and treatment.