Role of low-level laser therapy added to facial expression exercises in patients with idiopathic facial (Bell's) palsy

Abstract

The aim of the present study was to investigate the efficacy of low-level laser therapy in conjunction with conventional facial exercise treatment on functional outcomes during the early recovery period in patients with facial paralysis. Forty-six patients (mean age 41 ± 9.7 years; 40 women and 6 men) were randomized into two groups. Patients in the first group received low-level laser treatment as well as facial exercise treatment, while patients in the second group participated in facial exercise intervention alone. Laser treatment was administered at a wavelength of 830 nm, output power of 100 Mw, and frequency of 1 KHz using a gallium-aluminum-arsenide (GaAIAs, infrared laser) diode laser. A mean energy density of 10 J/cm² was administered to eight points of the affected side of the face three times per week, for a total of 6 weeks. The rate of facial improvement was evaluated using the facial disability index (FDI) before, 3 weeks after, and 6 weeks after treatment. Friedman analysis of variance was performed to compare the data from the parameters repeatedly measured in the inner-group analysis. Bonferroni correction was performed to compare between groups as a post hoc test if the variance analysis test result was significant. To detect the group differences, the Bonferroni Student t test was used. The Mann-Whitney U test was used to compare numeric data between the groups. In the exercise group, although no significant difference in FDI scores was noted between the start of treatment and week 3 (p < 0.05), significant improvement was observed at week 6 (p < 0.001). In the laser group, significant improvement in FDI scores relative to baseline was observed at 3 and 6 weeks (p < 0.001). Improvements in FDI scores were significantly greater at weeks 3 and 6 in the laser group than those in the exercise group (p < 0.05). Our findings indicate that combined treatment with low-level laser therapy (LLLT) and exercise therapy is associated with significant improvements in FDI when compared with exercise therapy alone.

Keywords: Facial nerve palsy; Low-level laser therapy; Rehabilitation.