Objectives We present this systematic review and meta-analyses to evaluate current evidence on the prevalence of depression, anxiety, and stress in patients with oral lichen planus and their magnitude of association. Material and methods We searched PubMed, Embase, Web of Science, Scopus, PsycInfo, and Google Scholar for studies published before January 2021. We evaluated the quality of studies using a specific method for systematic reviews addressing prevalence questions, designed by the Joanna Briggs Institute. We carried out meta-analyses and performed heterogeneity, subgroups, meta-regression, and small-study effects analyses. Results Fifty-one studies (which recruited 6,815 patients) met the inclusion criteria. Our results reveal a high prevalence of depression (31.19%), anxiety (54.76%), and stress (41.10%) in oral lichen planus. Furthermore, OLP patients presented a significantly higher relative frequency than control group without OLP for depression (OR = 6.15, 95% CI = 2.73–13.89, p < 0.001), anxiety (OR = 3.51, 95% CI = 2.10–5.85, p < 0.001), and stress (OR = 3.64, 95% CI = 1.48–8.94, p = 0.005), showing large effect sizes. Subgroups meta-analyses showed the relevance of the participation of psychologists and psychiatrists in the diagnosis of depression, anxiety, and stress in patients with OLP. Multivariable meta-regression analysis showed the importance of the comorbidity of depression-anxiety in patients with OLP. Conclusions Our systematic review and meta-analysis show that patients with OLP suffer a higher prevalence of depression, anxiety, and stress, being more frequent than in general population. Clinical relevance In the dental clinic, especially dentists should be aware of depression, anxiety, and stress in OLP patients to achieve a correct referral.

Objectives The association of OLP with other autoimmune processes points to the possibility that OLP‐affected patients are actually developing an autoimmune status that predisposes them to autoaggression against different targets. This systematic review and meta‐analysis aim to evaluate the current evidence on the prevalence of autoimmune disorders in patients with OLP and their magnitude of association. Methods We searched PubMed, Embase, Web of Science, Scopus databases for the studies published before May 2021, with no limitation in regards to their publication date or language. We evaluated the quality of studies, carried out meta‐analyses and performed heterogeneity, subgroups, meta‐regression, and small‐study effects analyses. Results Inclusion criteria were met by 153 studies (23,327 patients). Our results indicate the existence of high prevalence and a frequent association between OLP and some autoimmune disorders, especially in regards to thyroid disease (PP = 7.96%, 95% CI = 6.32–9.75; OR = 1.99, 95% CI = 1.60–2.49, p < 0.001) and diabetes mellitus (PP = 9.41%,95% CI = 8.16–10.74; OR = 1.64, 95% CI = 1.34–2.00, p < 0.001). Conclusions Our study demonstrates the existence of a comorbidity between autoimmune thyroid diseases as well as between diabetes mellitus and OLP respectively. Quality of evidence should be upgraded on other autoimmune diseases (fibromyalgia, gastrointestinal disorders, rheumatic diseases, Sjogren's syndrome, lupus erythematosus, and dermatological diseases) for which the current data do not allow us to know whether they are really associated with OLP.

Fas-associated death domain (FADD) upregulation, i.e., gene amplification, protein phosphorylation and/or overexpression, has shown promising prognostic implications in head and neck squamous cell carcinoma (HNSCC). This systematic review and meta-analysis aims to evaluate the clinicopathological and prognostic significance of FADD upregulation in HNSCC. We searched studies published before February 2020 through PubMed, Embase, Web of Science, Scopus and Google Scholar. We evaluated the quality of the studies included using the QUIPS tool. The impact of FADD upregulation on survival and clinicopathological variables was meta-analysed. We explored heterogeneity and their sources, conducted sensitivity analyses and investigated small-study effects. Thirteen studies (1,923 patients) met inclusion criteria. FADD immunohistochemical overexpression was statistically associated with worse overall survival (hazard ratio [HR] = 1.52, 95% confidence intervals [CI] = 1.28–1.81, p < 0.001), disease-specific survival (HR = 2.52, 95% CI = 1.61–3.96, p < 0.001), disease-free survival (HR = 1.67, 95% CI=1.29–2.15, p < 0.001), higher clinical stage (odds ratio [OR] = 1.72, 95% CI = 1.17–2.51, p = 0.005) and a large magnitude of effect with N+ status (OR = 2.36, 95% CI = 1.85–3.00, p < 0.001). FADD phosphorylation in ser-194 demonstrated no prognostic value, while no conclusive results can be drawn for FADD gene amplification. In conclusion, our findings indicate that immunohistochemical assessment of FADD overexpression could be incorporated into the prognostic evaluation of HNSCC.