Abstract
Objective To conduct a systematic review analyzing disease definitions and diagnostic criteria used in randomized controlled trials (RCTs) involving burning mouth syndrome (BMS). Methods A systematic search conducted in PubMed, Web of Science, PsycINFO, Cochrane Database/Cochrane Central, and Google Scholar that included RCTs on BMS published between 1994 and 2017 was performed. Results Considerable variability in BMS disease definitions and diagnostic criteria used created substantial heterogeneity in the selection of participants and weakened the rigor of the 36 RCTs identified. The analyzed RCTs routinely under-reported the methods used to rule in or out study participants and the number of individuals excluded from BMS RCTs. Conclusions Our findings indicate that a large proportion of participants enrolled in these studies may have had an underlying condition that could have explained their BMS symptoms. Thus, outcomes of therapeutic interventions from these BMS RCTs should be interpreted with caution due to heterogeneous disease definitions and diagnostic criteria. In order to improve the quality of clinical trials, future research should focus on establishing consensus for a single definition of BMS that includes specific inclusion and exclusion criteria that should be used to select study participants for clinical trials.