Symptoms and signs of temporomandibular disorders in patients with fibromyalgia and local myalgia of the temporomandibular system. A comparative study.

Symptoms and signs of temporomandibular disorders (TMD) in 46 patients were investigated and compared with those in 20 healthy individuals. Twenty-three patients had fibromyalgia (FM) and 23 had local myalgia (LM). Facial pain was assessed with a visual analogue scale, and a clinical examination was performed, including maximum voluntary mouth opening, temporomandibular joint sounds, tenderness to digital palpation in the masticatory muscles, pressure pain threshold and tolerance level of the superficial masseter muscle, intramuscular temperature, and maximum voluntary bite force. There was a difference in the number of tender muscles between the groups. Pressure pain threshold and tolerance levels were lower in the FM than in the LM group, whereas both showed lower values than a control group (C). The intramuscular temperature and maximum voluntary mouth opening were lower in the patient groups than in the C group. TMJ sounds showed a difference between all three groups. In conclusion, this study shows that FM patients frequently have TMD and indicates several differences between patients with FM and LM with regard to clinical variables.