Transcutaneous Electrical Nerve Stimulation (TENS) Performed with the Myo-monitor Induced Relaxation and Relief of Pain

Pantaleo, T.,M.D., Prayer-Galletti, F. M.D., Ph.D., Pini-Prato, g., M.D., and Prayer-Galletti, S.,M.D.: "An electromyographic study in patients with myofacial pain-Dysfunction syndrome". Bull. Group. int. Rech.sc Stomat. et Odont. Vol. 26, pp. 167-179, 1983.

Summary:
An electromypgraphic (EMG) study of ipsilateral masseter and temporalis muscles was undertaken in healthy volunteers and in patients with MPD syndrome, with the aim of getting further insight into the pathophysiology of this disease.  Unlike controls, patients had abnormal MKG features and displayed involuntary sustained EMG activity at rest, chiefly in the temporalis muscles.

Transcutaneous electrical nerve stimulation (TENS) performed with the Myo-monitor induced relaxation and relief of pain: these effects were however reversed by voluntary mouth closures.

The correction of occlusal position by acrylic splints was able to induce  persistent reduction or a suppression of the abnormal EMG activity at rest and a good relief of pain: moreover, after the corretion, higher levels of EMG activity were found during maximal  biting in the intercuspal position.
Mechanisms underlying these effects were discussed and in particular it was suggested that abnormal afferenct activity from periodontium and jaw muscles may contribute to the establishment of sustained contraction leading to muscular pain, which in turn may cause reflex muscle activity in vicious circles. 

The Myo-monitor and the myo-facial pain dysfunction syndrome

Wessberg GA., Dinham, Richard: "The Myo-monitor and the myo-facial pain dysfunction syndrome".  Journal of the Hawaii Dental Association.  vol. 10, No. 2, Aug. 1977.

Summary:
Thirty patients presented symptoms with the Myo-facial Pain Dysfunction Syndrome.  All of these patients received Myo-monitor oriented therapy and nearly all of them professed some initial relief or total remission of their symptoms during the short time  span of this study,

The data presented is based largely on clinical observations and patient response to comparison of their symptoms before and after treatment.  Symptoms evaluated were generally related to muscle tenderness and mandibular mobility.
Conclusion:
Due to clinical observations and patient response in this investigation, it is concluded that:

1. The centric occlusion position is seldom coincident with the myo-centric position of occlusion in patients who exhibit symptoms associated with Myofacial Pain Dysfunction Syndrome.
2. A Myo-monitor generated occlusal position affords some relief if not complete remission of symptoms in 90% of cases treated.
3. Long-term follow-up studies are necessary to evalutate the success of treatment.