Effects of low-level laser therapy versus soft occlusive splints on mouth opening and surface electromyography in females with temporomandibular dysfunction: A randomized-controlled study

BACKGROUND: Low level lasers have been used as an alternative pain relief therapy for muscle and joint pain, since it induces analgesic, anti-inflammatory, and biomodulation effects of the physiological cell functions. The effectiveness of low-level laser therapy in temporomandibular joint dysfunction (TMD) treatment, however, is not well established. Although Surface electromyography (sEMG) has been suggested as a complementary means in TMD diagnosis, the effect of conservative treatments on muscle activity has not yet been thoroughly correlated with (sEMG) findings. PURPOSE: To assess the efficacy of low-level laser therapy (LLLT) as compared to occlusive splint therapy (OST) on the TMJ opening index (TOI) and sEMG of masticatory muscles. MATERIALS AND METHODS: 112 female subjects suffering from unilateral myogenous TMD, aged 21-30 years-old, were recruited and divided into three groups: LLLT; soft occlusive splint therapy OST and a waitlist group as controls. OUTCOME MEASURES: TMJ opening index (TOI), Visual analogue scale (VAS), surface electromyography (sEMG). RESULTS: A significant reduction was reported in TOI, VAS and the sEMG within the LLLT and OST groups as well as significant decrease in all outcomes between groups in favor of the LLLT group (P< 0.0001). Meanwhile, there was a weak significant difference within the control group probably attributed to the analgesic. Post-hoc pairwise comparisons between groups [control vs occlusive splints, control vs low-level laser and low-level laser vs occlusive splints] revealed significant differences in the VAS and TOI [P = 0.0001; 95% CI: 0.9-2.2, 1.61-4.01, 0.65-1.96]. CONCLUSIONS: Findings support an evident short term therapeutic effect of the LLLT on improving VAS, TOI and sEMG in females suffering from myogenous TMD.