Traditional Chinese Medicine (TCM) for Temporomandibular Dysfunction (TMD): A Whole Systems Multi-site Trial

Studies of temporomandibular disorders (TMD) have shown that chronic pain in the temporomandibular joint (TMJ) and/or masticatory muscles affects more than 10% of adults at any one time and that one-third of adults will experience TMD over their lifespan (Von Korff et al. 1988). TMD includes a wide range of symptoms: facial pain, jaw-joint pain, headaches, earaches, dizziness, masticatory musculature hypertrophy, limited mouth opening, closed or open lock on the TMJ, abnormal occlusal wear, clicking or popping sounds in the jaw joint, and other complaints (NIH 1996). Although the etiology is poorly understood, longitudinal data suggest that TMD is an enduring, recurrent condition and a resistant problem for many (Dworkin et al. 1992a; Dworkin et al. 1989; Moss 1982; Gale 1978), and it affects individuals in all socioeconomic and ethnic groups (Smith & Syrop 1994). In a study of TMD patients in Kaiser Permanente Northwest (KPNW) in 1990-1995, the mean age was 40.5 years, and 80% of the patients were female. TMD subjects used 1.6 times the services of other health plan members (White 2001).

The Research Diagnostic Criteria for TMD (RDC/TMD) proposed by Dworkin et al. (Dworkin & LeResche 1992b) uses a dual axis system for diagnosing and classifying TMD patients. Axis I assigns physical diagnoses of the most commonly occurring masticatory muscle and/or TMJ disorders (arthralgia, arthritis, and arthroses of the TMJ). Axis II assesses behavioral, psychological and psychosocial factors; functional mandibular limitations; psychological distress, including depression; and Graded Scale of Chronic Pain (GCP) (Von Korff et al. 1992). The RDC/TMD criteria for Axes I and II have been used in numerous clinical research studies around the world (Ohrbach & Dworkin 1998; List et al. 1996; Rudy et al. 1995; Garofalo & Wesley 1998; Yap et al. 2002). An NIH-supported international consortium of RDC/TMD clinical researchers has been established to foster multinational studies of TMD using as their core the RDC/TMD standardized methods and criteria (http://www.rdc-tmdinternational.org/). The RDC/TMD has been suggested as a model system for the diagnosis and assessment of all chronic pain conditions (Garofolo & Wesley 1997; Dworkin, Sherman et al. 2002). The RDC/TMD is being used in this study for the primary endpoint.

Epidemiological studies of TMD have focused on estimating prevalence and describing characteristics of persons with and without the condition (Carlsson & LeResche 1995). In more than 75% of the studies reviewed, TMD was not adequately defined. Epidemiologic and clinical studies of TMD confirm its fundamental status as a chronic pain problem (Bell 1986; Fricton et al. 1987; Dworkin et al. 1992a). Yap et al. (2003) found that about 39% of TMD patients also are depressed, and 55% exhibit elevated levels of somatization. Similarly, Lee et al. (1995) found that TMD patients frequently present ear pain, neck pain, shoulder pain, headaches, and previous head or neck trauma.

In spite of a number of TMD clinical trials, no approach has been found to persistently and significantly reduce the pain and disability of this condition. Our recent phase II RCT (n=110 women) showed that Traditional Chinese Medicine (TCM), including acupuncture and herbs, was comparable to or better than comprehensive specialty usual care in reducing pain, and better in improving disability. The improvements did not persist, however, once TCM treatment ended. We hypothesize that this may have been due in part to their lack of education in self-care management. Thus, when their pain returned, they knew of no other option than returning to their TCM practitioner which was not permitted under the protocol. This suggests that the appropriate way to incorporate TCM into TMD care should include a self-care component for all participants. This proposal tests TCM versus self-care management (SC) in a realistic manner that is consistent with an integrative, stepped care strategy, one that begins with a minimal self-care intervention and increases the intensity in relation to patient needs. At multiple assessment points, participants not already on TCM will be randomized to self-care or TCM depending on their self-reported TMD pain levels. This study design is more clinically meaningful than a customary two-group randomization, which does not consider patient outcomes (see study Schema below).

We propose a multi-site (Tucson and Portland) phase II trial (n=150) that will evaluate the potential short-term pain and disability benefits of TCM and follow up for 18 months to compare long-term TCM to self-care management. Our specific hypotheses are: (1) among patients who fail to adequately improve on self-care management, those randomized to TCM will have less pain and disability over the short term (8 weeks) than those randomized to enhanced or extended self-care (SC); (2) patients placed on TCM due to inadequate improvement on SC will show long-term (12-18 months) outcomes similar to those continuing to benefit from SC. We will expand the patient population beyond our previous study to include both men and women, as well as individuals who have received previous TMD care (not TCM) and continue to experience TMD pain.

The TCM arm will incorporate whole systems research, which attempts to understand all components of the system of care in relation to the patient experience. Specific domains that will be considered in this study include patient-practitioner interaction, patient-centered outcomes, and the process of diagnosis and treatment as it proceeds through time and varies by practitioner.