Effectiveness of multiwave locked system laser on the treatment of patients with idiopathic Bell's palsy: a randomized double-blind placebo controlled trial

Lasers Med Sci. 2022 Dec;37(9):3495-3502. doi: 10.1007/s10103-022-03616-x. Epub 2022 Jul 26.


The objective of this study is to investigate the effect of scanning and point application of multiwave locked system (MLS) laser therapy on the recovery of patients with idiopathic Bell's palsy (IBP). A randomized double-blind placebo-controlled trial was carried out on 60 patients with subacute BP. Patients were randomly assigned into three groups of 20 patients each. Facial massage and facial exercises were applied to all patients. Group one received MLS laser as a manual scanning technique (10 J/cm2, area 50cm2, total energy 500 J). Group two received MLS laser using point application technique (10 J/point, 8 points, total 80 J). Group three received placebo laser. House-Brackmann scale (HBS) and facial disability index (FDI) were used to evaluate the facial recovery. Assessment was performed at baseline and after 3 and 6 weeks of treatment. Comparison within and between groups was performed statistically with significance level p < 0.05. Results showed significant improvement in the FDI and HBS after treatment in all groups. Both scanning and point application significantly improved the score of FDI and HBS more than placebo group. Scanning technique combined with facial massage and exercises had a more significant effect than the point application group or the placebo group in improving FDI and HBS scores after 3 and 6 weeks of treatment. The MLS laser is an effective physiotherapy method used for the treatment of patients with IBP. MLS laser in scanning or point application techniques was more effective than exercise alone with greater effect of scanning technique than point application technique.

Keywords: Bell’s palsy; Facial disability index; House–Brackmann scale; Multiwave locked system.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Bell Palsy* / radiotherapy
  • Double-Blind Method
  • Humans
  • Lasers
  • Low-Level Light Therapy* / methods