Early Treatment of TMJ May Prevent Chronic Pain and Disability
An estimated 75% of Americans will experience symptoms of temporomandibular joint and muscle disorder (TMJMD) in their lifetime.1 Studies show that the prevalence of TMJMD varies widely. In any given year, approximately
20 million adults (10% of women and 6% of men) have TMJMD pain.2 About 5.3 million people seek treatment for TMJMD within 6 to 12 months after onset of symptoms, with direct costs of treatment alone conservatively estimated at $2 billion annually.2
Although adequate data are lacking on indirect costs, research indicates that 28% of TMJMD patients report disability and limitations, as well as unemployment.3 Assuming that indirect costs would most likely exceed direct costs, projections from research put the total cost of TMJMD in excess of $4 billion per year. Thus, TMJMD is clearly a fiscal burden to both patients and society.
For many, symptoms of TMJMD resolve on their own without significant medical intervention; however, 5% to 10% of adults suffering from TMJMD symptoms require professional treatment.4 If pain persists beyond 3 to 6 months, the condition is considered chronic. Clinicians would benefit from an evidence-based method of determining which patients are at increased risk for developing chronic pain, as well as from empirically supported clinical interventions aimed at preventing acute pain from becoming chronic. The goal of this article is to review clinical studies to identify high-risk patients and suggest early interventions that may be used successfully during the acute phase of TMJMD.
The Problem of Pain
Temporomandibular joint (TMJ) pain is part of a broad category of disorders involving the muscles of mastication and the hard and soft tissues of the TMJ. A complex disorder, TMJMD may involve disc displacement, muscle disorders, internal derangement and/or degenerative changes in the joint, or combined muscle-joint disorders. According to Glaros and Lausten,5 the primary symptoms of TMJMD are: pain in the muscles of mastication in the preauricular area or in the TMJ; clicking, popping, or grating sounds in the joint; difficulty in opening the mouth wide; patients’ perception that their occlusion or bite is “off”; and jaw locking in the open or closed position.
Patients often cite pain as the principal reason for seeking medical or dental care.6,7 Managed care treatment costs per year for orofacial pain range from $12,000 to $20,000 per person.8 Von Korff, Lin, Fenton, and Saunders studied 372 TMJMD patients over a 3-year period, concluding that this pain population visited more healthcare providers than controls.9 As healthcare costs continue to escalate, research indicates that some cognitive-behavioral treatments offer a significant medical cost offset.10 Thus, not only are there physical and psychosocial benefits associated with preventing the progression from acute to chronic TMJMD, there are financial benefits, as well.
Clearly, there is a need for more effective and economic treatment modalities. More than a decade has passed since Stohler and Zarb urged the scientific community to adopt a “low-tech, high prudence therapeutic approach” to assessing and treating TMJMD.11 Since then, attention has shifted toward a behavioral medicine approach for treatment of TMJMD.
As the duration of pain increases, patients become more unresponsive to intervention.12 Conventional treatment of TMJMD includes surgery, occlusal adjustments, and pharmocotherapeutic techniques. Intra-oral appliances, nocturnal alarms, and physical therapy have also been used; however, conventional treatments fail to address the psychosocial factors of this painful, complex disorder. A comprehensive biopsychosocial (BPS) model and guidelines for applying the model to diagnosis and treatment is needed.
The similarities between TMJMD and low back pain (LBP) were first published by Dworkin.13 The prognoses for both disorders are normally recurrent and often chronic. Furthermore, the severity of pain and related unhealthy behaviors are highly inconsistent both between patients and over time. As noted by Von Korff, TMJMD, like LBP, can be described as “ an illness in search of a disease.”14 Low back pain and TMJMD often are idiopathic in nature. Invasive treatments have not been shown to be as beneficial or cost-effective as hoped. Because of the similarities between the disorders, several TMJMD studies have paralleled the clinical research program on LBP by Gatchel et al.15
Mishra, Gatchel, and Gardea compared the effectiveness of biofeedback (BFB), cognitive-behavioral therapy (CBT), combined biofeedback and CBT, and nonintervention on patients with TMJMD.16 Biofeedback was shown to be the most effective in pain reduction. The three treatment groups also had significantly reduced pain scores (from pre- to post-treatment) and significantly better mood scores relative to the nonintervention group.
The same researchers followed the original study with a 1-year outcome evaluation.17 All treatment groups sustained therapeutic gains from pre-treatment through 1-year follow-up, relative to the nonintervention group. At one year, the greatest improvements were found in the BFB/CBT group, relative to the group that received BFB alone. The researchers concluded that treatment received in the BFB group was directly associated to the patients’ primary physical pain complaint and likely contributed to greater significant gains immediately post-treatment. This association may have influenced patient motivation to complete in-session treatment and comply with home practice.
Improvements noted in the combined BFB/CBT group at 1 year may be due to the amalgamation of short-term benefits of BFB and long-standing benefits realized after CBT, resulting in a modification of lifestyle. Resulting change following CBT requires more time to fully understand, accept, and put changes into practice. Immediate positive outcomes provided by BFB intervention, combined with longer-term gains provided by the CBT treatment, were thought to elucidate the increased improvement in both physical and emotional functioning of the 1-year BFB/CBT group.
Early Intervention vs. Nonintervention
The aforementioned studies initiated the trend toward a biopsychosocial treatment approach. This low-cost and noninvasive therapeutic method stimulated a series of studies supported by the National Institutes of Health of acute patients with TMJMD. The first issue addressed in this series of studies was whether the progression from acute to chronic TMJMD pain could be prevented by early intervention with patients considered at risk for developing chronic pain. Epker, Gatchel, and Ellis18 created a statistical algorithm (based on a logistic regression model) using certain components of the Research Diagnostic Criteria/Temporomandibular Disorders (RDC/TMD).19