Place of placebo therapy in the treatment of burning mouth syndrome: A systematic review.

Abstract

Burning mouth syndrome (BMS) is defined as an idiopathic orofacial pain with intraoral burning or dysesthesia. This systematic review aimed to analyze the scientific literature with regard to the effectiveness of placebo therapy in patients with BMS. A literature search was conducted through the PubMed-indexed journals within MEDLINE®, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Trip databases from their inception to May 31, 2022. The search terms were defined by combining (medical subject headings (MeSH) terms OR keywords) "burning mouth syndrome" AND (MeSH terms OR keywords) "placebo". Methodological quality assessments were performed utilizing the Joanna Briggs Institute (JBI) Critical Appraisal tool to attribute scores from 1 to 11 to the selected studies. The literature search, study selection and data extraction were carried out by 2 authors. Disagreements between the authors were resolved by the 3rd author, if necessary. A total of 44 articles met the inclusion criteria. After assessing full-text articles for eligibility, 20 articles were excluded. Consequently, 24 articles were retained. A total of 21 studies included in this systematic review had a low score of bias. In 13 studies, a positive response to placebo was noted. Among them, 7 showed a placebo response indistinguishable from active treatment. These changes were more pronounced in patients receiving placebo therapy compared to active treatment in 1 study. Placebo therapy may occasionally be beneficial and ethically acceptable for patients with BMS. To get stronger evidence for the use of a placebo, future studies with standardized methodology and outcomes are required.