Salivary and serum biomarkers to evaluate psychological disorders in burning mouth syndrome: A systematic review and meta‐analysis

Abstract Background Burning mouth syndrome is a chronic pain syndrome mainly characterized by an intensive burning sensation of tongue. Previous studies have suggested that saliva/serum biomarkers in burning mouth syndrome might be associated with psychological disorders. The aim of systematic review was to observe whether the biomarkers in serum/saliva could be an alternative method to evaluate the psychological disorders in patients with burning mouth syndrome. Materials and Methods The PubMed, Embase, and Cochrane Library databases were searched for papers published up to March 15, 2023. Risk of bias was measured by using the Newcastle‐Ottawa Scale. RevMan was used for meta‐analysis. Results A total of 467 articles were screened, which of 12 studies were included. These studies collected 43 different biomarkers in saliva and 35 in serum. Of these biomarkers, only three (cortisol, α‐amylase, and IL‐6) were analyzed in two or more studies. Only salivary cortisol levels were significantly higher in the patient group compared to the controls (Mean Difference = 1.39; 95% CI [0.80–1.97]; p < 0.001). Moreover, cortisol might be relevant to psychological scores, especially anxiety. Conclusion Different papers have investigated salivary and serum biomarkers in burning mouth syndrome patients with controversial results. This meta‐analysis showed that cortisol levels in saliva may be a potential biomarker to assess the psychological disorders in burning mouth syndrome patients.