The term “Temporomandibular Disorders” or TMD refers to a group of clinical conditions that involve the temporomandibular joint and associated tissues, which may manifest as pain in the temporomandibular region, limitations in jaw movements, and temporomandibular joint sounds such as clicking or crepitus during jaw movements, and have a prevalence of approximately 8% in the adult population.1,2 Despite TMD being so common, the etiology and pathogenesis of most TMD conditions remain unclear. Factors impeding insights into their etiology and pathogenesis have included difficulties in case definition and the lack of standardized diagnostic criteria, and this led Dworkin and LeResche in 1992 to publish their landmark paper3 17 years ago in this journal (when it was known as the Journal of Craniomandibular Disorders Facial and Oral Pain). In the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), they provided diagnostic parameters to allow for standardization and replication of research approaches of most TMD conditions. A particular feature of the RDC/TMD is their dual-axis approach providing definition of not only physical findings (Axis I) but also psychosocial status and pain-related disability (Axis II) of the TMD patient. Another feature of the RDC/TMD is that by drawing attention to Axis II aspects of case definition, it built upon the emerging concept at the time of the biopsychosocial model of diseases and disorders and drove home the need for clinicians and researchers to be mindful of the role and impact that psychosocial factors and disability may be playing in the patient’s condition and its management. Indeed, clinical research reports4-6 in this issue of the Journal of Orofacial Pain provide further evidence of the importance of these factors. The publication of the RDC/TMD also spurred, as intended, an upsurge in clinical research into TMD, and the increased interest in TMD and in their management also has led to considerable research in animal models of acute or chronic temporomandibular pain such that new insights have been provided into the mechanisms underlying TMD signs and symptoms.
Numerous papers and symposia focusing on TMD and the use of the RDC/TMD have resulted in the intervening 17 years since the RDC/TMD were published, including the formation a few years ago of the International Consortium for RDC/TMD-Based Research, which also recently held a symposium at the annual conference of the International Association for Dental Research held in Toronto to highlight steps being taken to revise and update the RDC/TMD. The Focus Article by Drs Steenks and de Wijer8 in this issue of the journal draws particular attention to this need, and raises concerns about the reliability and validity of the RDC/TMD diagnostic approaches and their clinical applicability for the optimal care of TMD patients. In the three Critical Commentaries on the Focus Article, Drs Goulet,9 Greene,10 and Svensson11 bring their perspectives on the important “messages” in the Focus Article. They agree that there is a need to upgrade the RDC/TMD, and point out that such a process is now indeed taking place. Upcoming issues of this journal will provide research findings bearing on this important topic in the orofacial pain field.
Finally, I would like to note that Dr Linda LeResche has recently stepped down as Associate Editor of the journal. Dr LeResche has made a tremendous contribution to the journal, and the editorial board is very grateful for her advice and her editorial role in handling the review of articles that have focused especially on epidemiologic and psychosocial aspects of orofacial pain. Thanks, Linda! Dr LeResche’s place as Associate Editor has been taken by Dr Ilana Eli from Israel. Dr Eli is particularly well known internationally for her clinical activities and research related to psychosocial factors influencing orofacial pain; for the past several years, she has also been a regular contributor to the journal’s Literature Abstracts on this topic, and the editorial board looks forward to her “expanded” contributions to the journal. Welcome, Ilana!
Barry J. Sessle