There are tremendous variations between patients; some with many symptoms and signs and others with only a few significant ones. The severity of symptoms is in the perception of patients, not doctors. Many symptoms reported by patients who have TMD may also be caused by other disorders, such as earache, headache, dizziness or dental pain. Despite this, much research has been published throughout the world on TMD signs and symptoms in both medical and dental journals.
More commonly, research is conducted to study how patients with TMD are evaluated, diagnosed and treated. This is an area of great controversy and variety, because there are two schools of thought about the basis of TMD. One attributes TMD to a psycho-social (emotional) condition and the other to TMD as a physical/functional disorder. Most treating dentists worldwide believe that TMD patients have a physical/functional disorder and use various therapeutic modalities. Within this group, the majority of treating dentists do not use computerized measurement devices to record, scrutinize, analyze jaw movements, muscle and TMJ joint function. The authors of the articles included in this website do use computerized measurement devices and adhere to the physical/functional basis of TMD and the neuromuscular treatment approach.
Those who believe that TMD has no physical but only a psychological basis, test their patients with written questionnaires to determine their emotional and psychological status. Their treatment includes counselling, relaxation techniques and the prescription of a variety of medications. Success of treatment requires a subjective (personal) assessment (opinion) by the TMD patient either in verbal or via questionnaire and/or the treating doctor in determining that the treatment has been successful or has not. This does not produce hard data required for high quality scientific publishable research. Articles are plentiful in dental journals about this type of “successful” treatment for TMD.
Dentists who treat the physical/structural/functional disorder referred to as TMD also publish a great deal in the medical and dental literature. The weakness in this area of research lies in the variety of approaches to treatment. Most dentists believe in dental occlusion, the way the teeth fit together, is at the basis of most patients’ TMD condition. The exceptions include trauma, like a blow to the face or head which may damage the bones of the head and jaw, muscles, temporomandibular joints (TMJ) or teeth.
Because of the variety of different conditions under the term TMJ, research has been done on some of the treatment types. Once again, the limitation of the studies is often how success of treatment is measured. If it is only “how do you feel and function” or “how does the doctor think you feel and function”, the results are not scientific and not reproducible by other doctors performing research.