Clinical Study of the Effects of Treating Symptoms of Temporomandibular Joint Disease

A Clinical Study of the Effects of FACIAL-FLEX® in Treating Symptoms of Temporomandibular Joint Disease

Zarrinnia K., Braun R.J., Straja S.R.

The disorder of temporomandibular joint syndrome has likely existed since the dawn of man. The cardinal symptoms include temporomandibular joint (TMJ) pain, tenderness, joint noise (clicking and popping) and limitation of opening. The etiology of this syndrome has been at the center of controversy since its initial entry into dental literature. The viewpoint of investigators varies from the belief that this disorder is primarily a disturbance of the joint itself, which may be manifested as a size or shape deformity or an abnormality in the relationship of the various joint components to one another. Some researchers believe that the disorder stems from an extra-articular abnormality such as a disturbance in the function or anatomy of the muscles and tendons surrounding the joint. Still others have proposed the theory that imbalances in the function of the dentition could result in symptoms.

The diversity of symptoms and therapeutic techniques can make the proper choice of treatment a frustrating experience. Therapies for temporomandibular joint disease (TMD) have ranged from major surgical remodeling of the joint to extensive orthodontic therapy, which changes the alignment, and therefore interaction of the teeth. Many of the current treatment modalities for TMD can be expensive and traumatic for patients.

According to James R. Friction, DDS, Director of TMJ and Craniofacial Pain Clinic at the University of Minnesota School of Dentistry, only 5 to 10 percent of the general population has some form of TMD serious enough to warrant treatment. Even though this percentage is small, it represents a large number in real terms. That also translates into a significant expenditure for TMD treatment in this country. If an effective treatment that is also less costly and less traumatic can be found, the savings in patient morbidity and dollar cost could be tremendous.

One method of treating TMD that has widespread application is the use of occlusal (oral) splints. While this therapy is non-invasive and reasonable priced, it is coming under increasing criticism. Daott, et al have described the following proposed hypotheses for the mechanism of action of oral splints: (a) the repositioning of condyle and/or articular disc, (b) reduction in the electromyographic activity of the masticatory muscles, (c) modification of the patient’s “harmful” oral behavior, and (d) changes in the patient’s occlusion. These authors concluded that any of the above theories are lacking in consistency and poorly substantiated with clinical research.

This pilot study is an attempt to find out what effect Facial-Flex may have for patients with TMD. If successful in treating the symptoms of TMD, this device would provide a treatment that has no significant monetary or physical costs associated with it and provides a range of physical benefits to patients.


The FACIAL-FLEX device is designed to exercise a specific group of facial muscles, primarily the orbicularis oris and masseter. The device improves facial muscle tone. Facial-Flex operates on the principle of dynamic resistance. The device fits into the corners of the mouth and by utilizing varying tensions and movements, muscles are exercised. Tension is adjusted by using orthodontic elastics of varying strengths on the resistance unit.

Mark Hutchinson, MD, a professor and orthopedic surgeon at the University of Illinois at Chicago (UIC) College of Medicine, believes women’s joints are aligned slightly differently than men’s. He theorizes this may account for a higher incidence of temporomandibular joint symptoms in women.

Consequently for this study, only female subjects were selected to participate. Seventeen subjects from a first year dental school class were selected for the trial. Subjects were self-selected in that a general call for patients who experienced any pain or limitations of the TMJ was made. The participating subjects were randomly assigned to one of two groups: a) the Control Group and b) the experimental group (treatment group). The control group consisted of eight (8) subjects and the experimental control group consisted of nine (9) subjects. Since patients belonging to the control group and the treatment group were randomly extracted from the same population, there is no significant difference between the two groups that could bias the results.

The two groups were tested to evaluate the benefits of using the Facial-Flex exerciser over a 60 day period. One experimental group used the device twice a day and a control group did not use it.

Two tests were used to evaluate the patients condition; one the Dysfunction Index, DI, obtained by clinical examination of mandibular movement, TMJ noise and TMJ capsule palpation; the other the Palpation Index, PI, obtained by clinical examination/palpation of the extra oral and intraoral muscles. The Friction and Schiffman Craniomandibular Index, CMI, combines the Dysfunction and Palpation Indexes by the formula CMI=DI+PI/2. The CMI is universally accepted as a measure of the state of temporomandibular joint health and symptom severity.

The study recorded individual DI and PI Index figures for all patients before and after the 60 day test period. The table that follows includes both individual and average Craniomandibular index figures. The average CMI figures are compared below for both groups before and after the 60 day test. Improvement as measured by change in average.

CMI showed the control group improved by 11.8% while the experimental group improved by 41.8%.

Control Group:

Initial Exam: 7.37
Final Exam: 6.50
CMI change: .87 (11.8%)

Experimental Group:

Initial Exam: 9.31
Final Exam: 5.42
CMI change: 3.89 (41.8%)


The Craniomandibular Index, which is a combination of the palpation and dysfunction indexes, shows a statistically significant difference among the demonstrated improvements. Use of the CMI shows a 42% improvement in joint symptoms for the treatment group and only a 12% improvement for the control group.

Even though significant improvement in joint symptoms was obtained using the Facial-Flex, this study should be viewed as only the precursor of a larger controlled trial. This therapeutic system is promising. Not only in the dramatic results shown in this study, but in the fact that this therapy is cost effective and utilized no irreversible surgical or orthodontic therapies. Finally, other benefits accrue with the use of this device that enhance esthetics and therefore quality of life.

NOTE: CMI figures were re-calculated by James B. Godshalk, B.S., Chemical Engineering, University of Pennsylvania, January 2000.

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