The influence of estrogen on temporomandibular disorders: an umbrella review of systematic reviews identifying critical knowledge gaps

Background: The higher prevalence of temporomandibular disorders (TMD) among women suggests a potential influence of female hormones, particularly estrogen. However, the existing evidence regarding the role of estrogen in development and progression TMD remains inconsistent and fragmented. This umbrella review aimed to synthesize evidence from published systematic reviews examining the influence of estrogen-related factors on TMD, and to identify critical gaps in the existing knowledge. Methods: A comprehensive literature search was performed across PubMed, Scopus, Web of Science, CiNii, and Google Scholar using Medical Subject Headings (MeSH) terms and Boolean operators. The search covered studies published between 01 January 2000 and 01 September 2025, limited to English-language articles. The risk of bias of the included reviews was assessed using Risk of Bias in Systematic Reviews (ROBIS), and the extent of overlap between studies was evaluated using the corrected covered area. Results: Twenty studies were selected for full-text assessment, of which eight systematic reviews met the inclusion criteria. There was moderate evidence to support the role of estrogen in temporomandibular joint (TMJ) pain modulation; however, this conclusion was primarily derived from systematic reviews with heterogeneous methodologies and variable risk-of-bias profiles. The interpretation of these findings was constrained by the methodological limitations and risk of bias identified in several of the included reviews. Conclusions: TMD are multifactorial conditions involving interactions among hormonal, genetic, and functional factors. Although current evidence suggests a potential role of estrogen in modulating TMJ pain, findings remain inconclusive due to methodological variability and the risk of bias among existing systematic reviews. Significant knowledge gaps remain, highlighting the need for well-designed, longitudinal studies using standardized methodologies to clarify the role of estrogen in the pathophysiology of TMD. The PROSPERO Registration: CRD420251129568.