MLS® Laser Therapy and Bell’s palsy: a study on effectiveness

A study published in Lasers in Medical Science investigated the efficacy of MLS® Laser Therapy in patients with acute unilateral facial paralysis thanks to the M6 robotic device.

Bell’s palsy: what is it?

  • Bell’s palsy is the most common cause of acute unilateral facial paralysis, with an average incidence of 15-30 cases per 100,000.
  • It is caused by a dysfunction of the facial nerve, the VII cranial nerve. This nerve is responsible for the innervation of all facial muscles involved in facial expression. 
  • Bell’s palsy determines a marked weakness of the facial muscles on one side of the face, as well as: asymmetry of the smile caused by one corner of the mouth drooping, inability to close the eyelids, disappearance of wrinkles on the forehead, reduced stimulation of lacrimal and salivary glands.
  • The symptoms occur suddenly – they peak in as little as 72 hours – and are usually asymptomatic.
  • The drugs that are commonly used to treat it are corticosteroids – to reduce inflammation and swelling – and analgesics for the pain.
  • Physiotherapy – especially if started within the first 72 hours after the onset of symptoms – is essential to stimulate the facial nerve and help it maintain good muscle tone.

The study

Effectiveness of multiwave locked system laser on the treatment of patients with idiopathic Bell’s palsy: a randomized double-blind placebo controlled trial.” is a recent spontaneous study published in Lasers in Medical Science [vol. 37,9 (2022):3495-3502] aimed at investigating the treatment of patients affected by Bell’s palsy by exploiting the characteristics of the M6 robotic device for MLS® Laser Therapy. Although the publication in question is based on a randomised, double-blind placebo controlled trial, this field of application is still being investigated and studied.

The 60 patients enrolled were divided into 3 groups:

  • Group A – MLS® scanning + massages + exercises
  • Group B – spot MLS® + massages + exercises
  • Group C – Sham-Laser + massages + exercises

The treatment cycle consisted of 2 sessions per week for 6 weeks.

Each patient was assessed at the beginning, halfway through the cycle (after 3 weeks and 6 sessions) and at the end of the treatment cycle (after 6 weeks and 12 sessions).


The House-Brakman Scale (HBS) and the Facial Disability Index (FDI), consisting of two subscales – the Physical Facial Disability Index (PFDI) and the Social Facial Disability Index (SFDI) – were used to quantify the effects of laser therapy.

The results

  • The results showed that MLS® Laser Therapy, combined with massages and facial exercise, leads to a significant improvement at the end of the treatment cycle compared to the patient’s initial condition.
  • Already after 6 sessions – halfway though the treatment cycle – patients treated with MLS®, both in scanning and in spot mode, showed significant improvement in terms of motor and social function (Facial Disability Index) and degree of facial nerve paralysis (House–Brackmann Scale).
  • When compared to the control group (Sham-Laser), MLS® Laser Therapy showed significant superiority. In particular, scanning application showed a significant effect compared to both the control group and spot application.

Read more about the study publiced in Lasers in Medical Science and find more details at asalaser.com