**2. Materials and methods**

Papers were searched in PUBMED, using the Boolean search operators ("Laser" AND "Bell's Palsy," "Laser" AND "Facial Palsy," "LLLT" AND "Bell's Palsy," "Infrared" AND "Bell's Palsy"), covering the year 2012 to June 2022. All titles were then screened for relevancy. Non-English articles are excluded. We include only studies conducted on humans. All types of clinical studies evaluating the effectiveness of phototherapy are included, including case reports, case series, prospective studies, and controlled clinical trials. A manual search was also undertaken from the references of the selected papers.
