Early Treatment of TMD May Prevent Chronic Pain and Disability
Since we originally wrote about this topic in 2011,1 there have been some advancements in the literature on temporomandibular joint and muscle disorders, or temporomandibular disorders (TMDs). One advancement has been the first evidence-based diagnostic criteria developed to help health professionals better diagnose TMD, which affects an estimated 10% to 15% percent of Americans.2 In any given year, approximately 20 million adults (10% of women and 6% of men) have TMD pain.3 About 5.3 million people seek treatment for TMD within 6 to 12 months after onset of symptoms.3 Although adequate data are lacking on indirect costs, research indicates that 28% of TMD patients report disability and limitations, as well as unemployment.4 Assuming that indirect costs would most likely exceed direct costs, projections from research put the total cost of TMD in excess of $4 billion per year.5 Thus, TMD is clearly a fiscal burden to both patients and society.
Although TMD is commonly considered a jaw problem, researchers have determined that most people with chronic temporomandibular problems also contend with other ailments. For many, symptoms of TMD resolve on their own without significant medical intervention. However, 5% to 10% of adults suffering from TMD symptoms require professional treatment.6 If pain persists beyond 3 to 6 months, the condition is considered chronic.
The goal of this article is to review clinical studies that identify patients at high risk for chronic TMD and suggest early interventions that may be used successfully during the acute phase of TMD.
The Problem of Pain
Temporomandibular joint pain is part of a broad category of disorders involving the muscles of mastication and the hard and soft tissues of the temporomandibular joint. A complex disorder, TMD may involve disc displacement, muscle disorders, internal derangement and/or degenerative changes in the joint, or combined muscle-joint disorders. The primary symptoms of TMD that were defined in 2003 by Glaros and Lausten remain the same today: pain in the muscles of mastication in the preauricular area or in the temporomandibular joint; clicking, popping, or grating sounds in the joint; difficulty opening the mouth wide; a patient’s perception that their occlusion or bite is “off”; and jaw locking in the open or closed position.7
Different measures of pain also can serve as risk factors for TMD. In 2006, the National Institute of Dental and Craniofacial Research (NIDCR) introduced the very first large-scale, 7-year prospective study called Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA).8,9 The study has followed 2,737 healthy men and women (ages 18 to 44) to see who develops TMD and why. The latest published data are based on a median 2.8 years of follow up, during which 260 participants developed their first case of painful TMD, which translates to an incidence rate of 4% per year in the study cohort.
A notable finding of the OPPERA study was that high levels of pain sensitivity, as well as an increased heart rate, were associated with an increased likelihood for developing TMD.8 It is suspected that an increased heart rate is indicative of hyperactivity in the sympathetic nervous system, which may result from dysfunction in central processes that control baroreceptors.7 The OPPERA study also found that having a pain disorder (eg, low back pain, migraines, irritable bowel syndrome, etc.) increased one’s chances of developing TMD.9
Patients often cite pain as the main reason for seeking medical or dental care.10,11 Managed care treatment costs per year for orofacial pain range from $12,000 to $20,000 per person.12 Studying 372 TMD patients over a 3-year period, Von Korff et al, concluded that this pain population visited more health care providers than controls.13 As health care costs continue to escalate, research indicates that some cognitive-behavioral treatments offer a significant medical cost offset.14 Thus, not only are there physical and psychosocial benefits associated with preventing the progression from acute to chronic TMD, there are financial benefits, as well.
Clearly, more effective and economic treatment modalities are needed. It has been more than a decade since Stohler and Zarb urged the scientific community to adopt a “low-tech, high prudence therapeutic approach” to assessing and treating TMD.15 Since then, attention has shifted toward a behavioral medicine approach to treatment.
As the duration of pain increases, patients become less responsive to intervention.16 Conventional treatments of TMD include, surgery, occlusal adjustments, and pharmocotherapeutic techniques. Intra-oral appliances, nocturnal alarms, and physical therapy also have been used. However, conventional treatments fail to address the psychosocial factors of this painful, complex disorder. A comprehensive biopsychosocial model and guidelines for applying the model to diagnosis and treatment are needed.
Chronic Pain Links
Dworkin first identified the similarities between TMD and low back pain (LBP).17 Both disorders generally are recurrent, and they often are chronic. Furthermore, the severity of pain and related unhealthy behaviors are highly inconsistent between patients as well as over time. As noted by Von Korff, TMD, like LBP, can be described as “an illness in search of a disease.”18 LBP and TMD often are idiopathic in nature. Invasive treatments have not been shown to be as beneficial or cost-effective as had been hoped. Because of the similarities between the disorders, several TMD studies have paralleled Gatchel et al’s LBP clinical research program.19
Mishra et al compared the effectiveness of biofeedback (BFB), cognitive-behavioral therapy (CBT), combined BFB and CBT, and no intervention on patients with TMD.20 The 3 treatment groups had significantly reduced pain scores (from pre- to post-treatment) and significantly better mood scores relative to the group with no intervention. BFB was shown to be the most effective modality for reducing pain.