The association of sleep disturbances with burning mouth syndrome: An overlooked relationship-A qualitative systematic review

Objectives To review the relevant literature to assess whether patients with burning mouth syndrome (BMS) are more prone to have sleep disturbances than general population. Methods The literature search for relevant articles was from July 2020 to March 2021. A systematic search of PubMed, Embase, Google Scholar, Cochrane library, Dentistry & Oral Sciences Source, and Scopus was conducted to search for relevant studies. The quality of studies was assessed in accordance with the Joanna Briggs Institute's guidelines and using the software SUMARI-The System for the Unified Management, Assessment and Review of Information. Confidence in the findings was assessed using the GRADE-CERQual approach. Results A total of 1064 studies were initially identified from the search; six studies, two cross-sectional and four case-control, met the inclusion criteria and were selected for this systematic review. Sleep disturbances were a required outcome measured in selected studies evaluating symptoms of BMS. For studies that were included in the final analyses, BMS was found to relate to several dimensions of sleep including sleep disturbance and duration (n = 6), sleep affecting daytime function (n = 4), sleep quality (n = 6), sleep efficiency (n = 4), and ability to fall asleep (n = 4). Consistent evidence of moderate confidence found that BMS was associated with greater sleep disturbance, reduced sleep quality, increased time taken to fall asleep, reduced sleep efficiency, and poor daytime function, whereas evidence of low confidence was found regarding the association of BMS with reduced sleep duration. Conclusions Although the presented studies could not establish a direct causal relationship between BMS and sleep disturbances, it supports the evidence that sleep disturbance is associated with symptoms of BMS. Management strategies to improve sleep may be considered in future research for managing BMS patients.