Comorbidity between fibromyalgia and temporomandibular disorders. A systematic review

Abstract Objective Fibromyalgia (FM) is characterized by body-wide diffuse and chronic musculoskeletal pain that in some patients can include the masticatory muscles and temporomandibular joints; those patients are defined as having a temporomandibular disorder (TMD). The purpose of this systematic review is to study the comorbidity between FM and TMD, as well as the prevalence and characteristics of TMD in patients with fibromyalgia or the features and prevalence of FM in patients with TMD. Methods Our bibliographic search was conducted from 01/01/2005 to 31/05/2018 in Medline database using its free search engine PubMed and the keywords “fibromyalgia”, “temporomandibular joint disorder” and “orofacial pain”. Results Out of the 185 studies found in this search, only 19 met the inclusion criteria. These studies have shown a high prevalence of TMD in patients with fibromyalgia. Muscle pain, TMJ pain, and muscle tenderness on palpation are the most common symptoms. These results suggest the existence of comorbidity between TMD and FM which can be an etiological or aggravating factor for TMD, or it may represent a general vulnerability to pain disorders. Besides, the two pathologies may share some regional or central mechanisms in common. Conclusion The high prevalence of TMD in patients with fibromyalgia emphasizes the need to integrate the signs and symptoms of TMD in the diagnosis of FM in order to improve the pain management in these patients.