1. Aetna considers the Therabite Jaw Motion Rehabilitation System medically necessary to treat mandibular hypomobility caused by radiation in persons with head and neck cancers.

2. Aetna considers the Therabite Jaw Motion Rehabilitation System experimental and investigational for all other indications because of insufficient evidence in the peer-reviewed literature, including any of the following conditions:

   1. Closed lock treatment
   2. Facial burns
   3. Mandibular coronoid hyperplasia
   4. Non-surgical temporomandibular joint (TMJ) dysfunction
   5. Oral burns
   6. Orofacial pain
   7. Post-surgical TMJ rehabilitation
   8. Rehabilitation following facial trauma
   9. Stroke
   10. Treacher Collins syndrome
   11. Trismus.

Most head and neck cancers are treated with surgery, radiation, or a combination of the 2 modalities.  The choice of treatment depends primarily on the anatomic site, extent and histologic grading of the tumor, and the presence of infection.  Modern reconstructive techniques permit cancer patients, especially those with head and neck malignancies, to undergo more immediate reconstruction and thereby achieve better functional outcomes while still progressing through multimodality treatment in a timely manner.  However, the more aggressive the cancer therapy, the more it places patients at risk for oral complications related to treatment.

One of the major complications from therapeutic administration of ionizing radiation to the head and neck is mandibular hypomobility -- a reduction in mandibular range of motion (ROM) caused by radiation-induced scarring and contraction of soft tissues surrounding the jaw.  Clinically, the severity of mandibular hypomobility is related to the radiation dose, volume of tissue treated, and age of the patient.

Mandibular hypomobility is treated by stretching the scar tissue.  Methods commonly used to stretch the scar tissue and increase mandibular ROM include: (i) oral opening exercises; (ii) stacking tongue blades between the molars; (iii) continuous passive motion of the jaw; and/or (iv) stretching the jaw using custom-made mechanical devices.  One such custom-made device is the Therabite, a threaded screw-type instrument that is placed between the teeth and turned to gradually open the jaw, much like a car jack.  Preliminary evidence indicates that the Therabite is more effective than other modalities in maintaining and/or improving mandibular ROM in irradiated patients.  There are, however, inadequate outcomes data comparing the Therabite to more conventional methods to support the use of Therabite for any other condition.

Melchers and associates (2009) examined the factors that may influence Therabite exercise adherence, how these interrelate and provided aims for interventions to increase adherence.  These researchers performed a multi-center, formal-evaluative qualitative retrospective study.  A total of 21 patients treated for head-neck cancer were interviewed in semi-structured, in-depth interviews.  Internal motivation to exercise, the perceived effect, self-discipline and having a clear exercise goal influenced Therabite exercise adherence positively.  Perceiving no effect, limitation in Therabite opening range and reaching the exercise goal or a plateau in mouth opening were negative influences.  Pain, anxiety and physiotherapists could influence adherence both positively and negatively.  Based on the results, a model for Therabite exercise adherence was proposed.  It is important to signal and evaluate the factors that negatively influencing Therabite adherence, especially before there is a perceived effect.  The authors stated that research is needed to examine why some patients do not achieve results despite high exercise adherence, to identify effective exercise regimens and to assess proposed interventions aimed to increase Therabite exercise adherence.