Follow-up results of a randomized clinical trial for low-level laser therapy in painful TMD of muscular origins.

Objective: To characterize short- and long-term assessment of the low-intensity laser therapy (LLLT) effectiveness in women with TMD of muscular origins and to evaluate whether the information about the treatment received (active or placebo) modifies the pain intensity.Methods: Forty-one women with painful TMD (31.7 ± 5.2 years) were divided into laser (n = 20) and placebo (n = 21) groups. The pain intensity was measured at the baseline, after the LLLT (T8), 6 and 12 months. At the 6-month follow-up, the groups received information about the active or placebo treatment.Results: At T8 and 6-month, both active and placebo LLLT were effective in reducing pain (p < .05). After one year, the groups showed similar pain. Active LLLT was more effective in reducing pain palpation (p = .001) and referred pain (p = .04) in the region of the TMJs. The information about the treatment modified the perceived pain intensity.Conclusion: Active and placebo LLLT are effective for painful TMD of muscular origins in the short-term. Information about the treatment impairs the subjective perception of pain.