Prevalence of temporomandibular disorders in fibromyalgia and failed back syndrome patients: A blinded prospective comparison study Ramesh Balasubramaniam, BDSc, a Reny de Leeuw, DDS, PhD, b Hua Zhu, MS, c Robert B. Nickerson, MD, d Jeffrey P. Okeson, DMD, e and Charles R. Carlson, PhD, f Lexington, KY UNIVERSITY OF KENTUCKY Objectives. The objective of this study was to determine the prevalence of temporomandibular disorders (TMD) and evaluate psychosocial domains in patients with fibromyalgia (FM) compared with patients with failed back syndrome (FBS). Study design. The study included 51 (32 FM and 19 FBS) adult patients who were administered orofacial pain and psychological questionnaires before a clinical examination. Presence of TMD was diagnosed according to the Research Diagnostic Criteria for TMD. Results. Fifty-three percent of the FM patients reported having face pain compared with 11% of the FBS patients. Of those FM patients who reported face pain, 71% fulfilled the criteria for a diagnosable TMD. FM patients had significantly higher subscale scores for somatization, obsessive-compulsive, medication used for sleep, and fatigue compared with FBS patients. Eighty-seven percent of the FM patients reported a stressful event and 42.3% had symptoms indicating posttraumatic stress disorder. Conclusion. The high prevalence of TMD and psychosocial dysfunction among FM patients suggests wide-reaching dysregulation of autonomic and hypothalamic-pituitary-adrenal axis functions. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:204-16) Fibromyalgia (FM) is defined by the American College of Rheumatology (ACR) as a disorder characterized by widespread pain and tenderness in at least 11 of 18 musculoskeletal sites for at least 3 months. 1 Although the ACR criteria are the standard criteria currently used to study FM, it is believed that FM is not a musculo- skeletal disorder per se; rather, it represents one end of a spectrum of disorders that encompasses conditions known as chronic widespread pain characterized by widespread tenderness, pain severity, and distress. 2-6 Given that the pain in FM is widespread and can involve various parts of the body, it would be reason- able to suggest that FM may overlap with temporoman- dibular disorder (TMD), which is “a collective term embracing a number of clinical problems that involve the masticatory musculature, the temporomandibular joint and associated structures.” 7, p116 Numerous stud- ies in the past have linked FM and TMD. 8-13 These studies have affirmed the frequency with which TM symptoms are found among FM patients. In a large sample of FM patients, 94% reported TMD symptoms including pain and difficulty chewing and mouth opening, which followed preexisting FM pain of long duration. 14 Studies including clinical examination revealed that 68% to 97% of FM patients have signs and symptoms of TMD. 9,15,16 FM patients more com- monly report TMD symptoms than vice versa. 9 One study reported that 75% of FM patients met the criteria for TMD, whereas only 18% of TMD patients fulfilled the FM criteria. Debate persists whether FM and TMD should be considered distinct clinical entities or not. FM has been considered far more debilitating with respect to number of pain sites, somatic symptoms, and level of pain intensity than TMD. 17 In addition, FM patients report more functional disability, work diffi- culty, and overall health dissatisfaction. 9 On the con- trary, one study found that select clinical features, in- cluding muscle palpation and mouth opening did not differ between FM patients and those with masticatory myofascial pain syndrome. 18 Another study found that a Former Resident, Orofacial Pain, Orofacial Pain Center, University of Kentucky. b Associate Professor, Orofacial Pain Center, University of Kentucky. c PhD candidate, Department of Statistics, University of Kentucky. d Associate Professor, Department of Physical Medicine and Rehabil- itation, School of Medicine, University of Kentucky. e Professor and Director of Orofacial Pain Center, University of Kentucky. f Professor, Orofacial Pain Center and Department of Psychology, University of Kentucky. Received for publication Oct 9, 2006; returned for revision Dec 22, 2006; accepted for publication Jan 5, 2007. 1079-2104/$ - see front matter © 2007 Mosby, Inc. All rights reserved. doi:10.1016/j.tripleo.2007.01.012 204