Dr. William Maixner and colleagues at the University of North Carolina at Chapel Hill (UNC), School of Dentistry, currently involved in the multi-center Orofacial Pain Prospective Evaluation and Risk Assessment (OPPERA) study of TMD, have taken a second look at an earlier study that inspired the more ambitious OPPERA investigation. The smaller study, conducted between 2005 and 2009, explored genetic risk factors for TMD and collected multiple measurements and questionnaire data from several hundred women with and without TMD.
The team’s second look divided the study group into: women without TMD and no other pain condition (the controls) and TMD patients with either 1) TMD only, 2) TMD plus one other comorbid pain condition, and 3) TMD plus 2 or more comorbid conditions.
The seven comorbid conditions studied were TMD, fibromyalgia, chronic fatigue syndrome, interstitial cystitis, chronic pelvic pain, frequent headaches, and frequent low back pain. The presence of one or more of these comorbid conditions with TMD was based on patients’ self-reports. The UNC researchers’ hunch was that the more comorbid pain conditions TMD patients reported, the more likely would they find dysregulation in the functioning of major physiological systems or “domains” in the body. The domains they chose were sensory, autonomic, inflammatory and psychological “based on evidence of system contributions to pain amplification and on availability of data being collected.” They then took the various measurements they had collected in the earlier study, arrayed them across the various domains (e.g., measures of blood pressure and heart rate would go into the autonomic domain, measures of inflammatory markers in the bloodstream would go into the inflammatory domain), and devised statistical means of determining when the measurements for a particular domain added up to dysregulation. Then they looked at how these measures varied across their categories of subjects in the study.
Among their findings:
Overall, the researchers emphasized that there was great heterogeneity (differences) in the pain profiles they were able to draw for their subjects. They describe their research as a “work in progress,” dependent on the kinds of data available from the earlier study and limited by its small size. (In particular among TMD cases there were only 14 who reported TMD only.) But their main point was that given the complexity of TMD and other chronic pain conditions, treatment strategies would be better served by taking into account the contribution of major physiological systems and their interactions in the experience of chronic pain.
In terms of TMD, stop looking at the teeth, the muscles of mastication and the jaws as the be-and end-all of TMD chronic pain and dysfunction, and see what else is going on in the body.
By Joan Wilentz, The TMJ Association
Source: Chen H, Nackley A, Miller V, Diatchenko L, Maixner W. Multi system Dysregulation in Painful Temporomandibular Disorders. J Pain. 2013 May 28. doi:pii: S1526-5900(13)00960-7. 10.1016/j.jpain.2013.03.011.