Editor's comment: There is a high frequency of temporomandibular dysfunction (TMD) in people with fibromyalgia. One study found that as many as one in three FM patients may also have TMD (also referred to as TMJ). TMD is characterized by pain in the jaw joint and masticatory (chewing) muscles. It usually also results in limitations of jaw movement.
Facial Pain Associated With Fibromyalgia Can Be Marked by Abnormal Neuromuscular Control: A Cross-Sectional Study.
By Maísa S. Gui, et al.
BACKGROUND: Temporomandibular disorder (TMD) development in fibromyalgia syndrome (FMS) is not yet fully understood but altered neuromuscular control in FMS may play a role in triggering TMD.
OBJECTIVE: The purpose of this study was to verify the association between neuromuscular control and chronic facial pain in groups of patients with FMS and TMD.
DESIGN: A cross-sectional study was conducted.
METHODS: This study involved an analysis of facial pain, electromyographic amplitude and frequency of masticatory muscles in patients with FMS (n=27) and TMD (n=28). All subjects were evaluated according to RDC/TMD and surface electromyography (SEMG). Myoelectric signal calculations were performed using the Root Mean Square (RMS) and Median Frequency (MNF) of signals.
RESULTS: Our data reveals premature interruption of masticatory muscle contraction in both patient groups but a significant correlation was also found between higher MNF values and increased facial pain. This is probably related to FMS since this correlation was not found in patients with TMD only. Facial pain and increased SEMG activity during mandibular rest were also positively correlated.
LIMITATIONS: Temporal conclusions cannot be drawn from our study. Also, the study lacked a comparison group of patients with FMS without TMD as well as a healthy control group.
CONCLUSIONS: Altered neuromuscular control in masticatory muscles may be correlated with perceived facial pain in patients with FMS.
Source: Physical Therapy, April 18, 2013. By Maísa S. Gui, Cristiane R. Pedroni, Luana M. M. Aquino, Marcele J. Pimentel, Marcelo Correa Alves, Sueli Rossini, Rubens Reimao, Fausto Berzin, Amélia P. Marques and Célia M. Rizzatti-Barbosa. M.S. Gui, Department of Anatomy, Piracicaba Dental School, University of Campinas, Piracicaba, Sao Paulo, Brazil. Mailing address: Joao Bueno Filho Street, 41, Montezuma, Brazil 13480-358. E-mail: firstname.lastname@example.org