From Epithelial Barrier Disruption to Gingival Remodeling in Periodontitis: The Roles of Snail1 and Twist1 in Epithelial–Mesenchymal Transition

Periodontitis is a chronic inflammatory disease initiated by dysbiotic biofilms and sustained by an altered host response, resulting in progressive destruction of the tooth-supporting tissues. Alongside immune-mediated damage, epithelial–mesenchymal transition has been proposed as a contributing mechanism in gingival barrier disruption and periodontal tissue remodeling. This narrative review examines the roles of the EMT-related transcription factors Snail1 and Twist1 in periodontitis, with particular focus on their involvement in epithelial junction loss, mesenchymal activation, and disease-associated tissue change. Relevant literature was identified through targeted searches of PubMed/MEDLINE and Google Scholar using terms related to periodontitis, gingival epithelium, EMT, Snail, and Twist, while selected non-periodontal studies were used only for mechanistic context where direct evidence was limited. Current findings suggest that periodontal disease is commonly associated with reduced epithelial adhesion markers and increased mesenchymal-associated markers, with Snail1 appearing more closely linked to epithelial repression and Twist1 to motility and matrix remodeling. However, the evidence remains largely preclinical or associative. Overall, Snail1 and Twist1 may participate in EMT-like remodeling in periodontitis, but periodontal-specific mechanistic and functional studies are still needed to clarify causality and clinical relevance.