Comparative clinical study of light analgesic effect on temporomandibular disorder (TMD) using red and infrared led therapy

Abstract

Low-level laser therapy (LLLT) has been widely applied in pain relief in several clinical situations, including temporomandibular disorders (TMD). However, the effects of LED therapy on TMD has not been investigated. This study aims to evaluate the effects of red and infrared LEDs on: (1) tissue temperature in ex vivo and (2) pain relief and mandibular range of motion in patients with TMD. Thirty patients between 18 and 40years old were included and randomly assigned to three groups. The two experimental groups were: the red LED (630 ± 10nm) group and the infrared LED (850 ± 10nm) group. The irradiation parameters were 150mW, 300mW/cm(2), 18J/cm(2), and 9J/point. The positive control group received an infrared laser (780nm) with 70mW, 1.7W/cm(2), 105J/cm(2), and 4.2J/point. LED and laser therapies were applied bilaterally to the face for 60s/point. Five points were irradiated: three points around the temporomandibular joint (TMJ), one point for the temporalis, and one near the masseter. Eight sessions of phototherapy were performed, twice a week for 4weeks. Pain induced by palpating the masseter muscle and mandibular range of motion (maximum oral aperture) were measured at baseline, immediately after treatment, 7days after treatment, and 30days after treatment. There was an increase in tissue temperature during both the red and the infrared LED irradiation in ex vivo. There was a significant reduction of pain and increase of the maximum oral aperture for all groups (p ≥ 0.05). There was no significant difference in pain scores and maximum oral aperture between groups at baseline or any periods after treatment (p ≥ 0.05). The current study showed that red and infrared LED therapy can be useful in improving outcomes related to pain relief and orofacial function for TMD patients. We conclude that LED devices constitute an attractive alternative for LLLT.