Diagnosis in the Computer Age
Often, a virtually imperceptible (invisible) misalignment of the jaws with upper and lower teeth meeting in the wrong place can be at the root of TMDs. This misalignment can prevent the jaws from meeting in a position, which maintains muscular relaxation and health as nature intended, requiring the muscles to function in an uncomfortable manner. The misalignment may look like a typical dental malocclusion or may look like a beautiful occlusion of the teeth. By visually observing, feeling and listening alone, doctors cannot totally observe and evaluate the presence of subtle dysfunction. To trace and identify this malocclusion, or “unhealthy bite,” and to measure the associated muscle function requires a revolutionary set of computerized instruments developed over the past forty years.
The Computerized Mandibular Scan (CMS)
The CMS is a tracking device that records, in three dimensions, the delicate functioning movements of the jaw with accuracy in tenths of a millimeter. Recordings are made of the movement of a small magnet temporarily attached to the gum below the lower front teeth. Opening, closing, swallowing and chewing movements can be scrutinized and analyzed. The natural occlusion and the healthy neuromuscular occlusion treatment positions can be located with this computerized instrument. This testing is used at the initiation of treatment and thereafter to evaluate the accuracy of jaw position at the treatment occlusion.
The Electromyograph (EMG)
This instrument measures and analyzes the electrical activity in the muscles that move the jaw at rest and during function. In health, muscles rest with low levels of electrical activity and function with high levels of balanced activity. In TMD the reverse is often observed. Illustrative data demonstrate the resting EMG activity before and after TENS (electrical stimulation therapy to relax muscles) as well as the Functioning (clench) EMG activity in the natural bite and in the corrected neuromuscular occlusion used for treatment. EMG is a painless test, which is performed using surface electrodes placed bilaterally, on the anterior temporalis, masseter and digastric muscles. The device demonstrated in the graphics below can also monitor a fourth pair of muscles selected by the dentist. Resting electrical activity as well as maximum voluntary clenching, representing the two ends of the spectrum of muscle function can be tested with EMG.
The Electrosonograph (ESG)
Recordings of sounds produced within the jaw joint (TMJ) can be recorded and analyzed during opening and closing of the mouth more sensitively, precisely and reproducibly than by the traditional technique of listening with a stethoscope. ESG records the frequency and amplitude (power) of the noise produced, as well as the position in the opening/closing at which sound is produced. This enables the dentist to evaluate whether there is damage within the TMJ and suggests its nature for which further study may be necessary. The test is performed by placement of a headpiece similar to that of a head set with vibration sensors (transducers) over the two temporomandibular joints (TMJ).
The treating dentist determines what type of imaging is necessary for each patient and at what point in the diagnosis or treatment it is necessary to obtain information from imaging. TMJ imaging includes various types of views such as lateral trans-cranial, panoramic, frontal, CT scans, and MRI when medically necessary to aid in the diagnosis and treatment of a patient.
The actual diagnosis is made by the TMD-trained dentist, who accumulates, analyzes and assimilates all of the information obtained from the patient’s history, clinical examination and various diagnostic tests described above. The computerized testing, which provides valuable information, does not make a diagnosis by itself. It is the trained doctor, who assesses all the data obtained, makes the diagnosis and determines the appropriate treatment plan for that patient. Actual treatment frequently involves the temporary creation of a new therapeutic biting position. This neuromuscular occlusion position incorporates healthy muscle function and proper interdigitation of the teeth to create a healthy, comfortable bite.