Purpose: Temporomandibular joint disorder (TMD) is a collective term used for a number of clinical signs and symptoms that involve the masticatory muscles, the temporomandibular joint (TMJ) and its associated structures. Since TMD is a multifactorial disorder, many modes of management have been reported to be effective in reducing or eliminating patient signs and symptoms (initially pain and clicking). There exists considerable debate, both on the part of the surgeon and the patient, regarding treatment (noninvasive or minimally invasive). These have ranged from occlusal adjustment, splint therapy, arthroscopy, surgery, laser therapy, cryotherapy and acupuncture. Low-level laser therapy (LLLT) has been used for pain control and healing. Use of low-level laser for TMD has been controversial, and shortcomings have been found in previous studies. The aim of this study was to evaluate the effectiveness of LLLT at 980 nm in TMD patients. Materials and Methods: We performed a single-blind clinical trial on 48 TMD patients. Before treatment, all patients were matched based on gender, pain, and clicking. There were no cases of degenerative joint disease (DJD) or parafunction (eg, bruxism) and the patients were otherwise healthy. The patients were randomly divided into experimental and placebo groups. In the study group, the patients were treated with LLL (980 nm, 80 Hz, 6 J) at three points over the TMJ (ie, 2 J per point and 1.5 J at the other sites of muscle pain) for 1 min. In the placebo group, the laser device was adjusted in the same positions but without power emission. Effectiveness of LLLT for pain and clicking in the groups was evaluated immediately, after 2 days, after 4 days, and then at 6 and 12 months using a visual analogue scale. To compare the magnitude of click, the chi-square test was used, and for pain severity the Mann-Whitney U-test was used to analyze the results. Results: The pain severity after treatment on day 4 in the experimental group was 2.4 ± 1.36, which was significantly less than the placebo groups results of 4.4 ± 1.84 (p < 0.001). Click reduction was 23.1% in the placebo group and 76.3% in the experimental group. The results were statistically significant for both pain and clicking without recurrence up to the 2-year follow-up period (p < 0.001). Conclusion: Low-level laser therapy (980 nm) was effective in management of TMD signs and symptoms and induced considerable reduction or elimination of pain severity and clicking. LLL applications can be an effective mode of management for selected patients with TMD.
Keywords: low-level laser, temporomandibular joint disease, pain and clicking