"Exposure to areca nut (Areca catechu) containing products with or without tobacco (ANCP/T) is currently believed to lead to<unk>  in individuals with genetic immunologic or nutritional predisposition to the disease." This hypersensitivity reaction results in a juxta-epithelial inflammation that leads to increased fibroblastic activity and decreased breakdown of fibers. The fibroblasts are phenotypically modified, and the fibers they form are more stable, produce thicker bundles that progressively become less elastic. once the original loosely arranged fibrous tissue is replaced by the ongoing<unk> , the movability of the<unk>  tissues is reduced, there is loss of flexibility and reduced opening of the mouth. These collagen fibers are non degradable and the phagocytic activity is minimized. According to a recent cross sectional study the time taken for return of salivary pH to baseline levels after chewing areca nut containing mixtures is significantly longer in habitual users with<unk>  when compared to unaffected users. Prolonged Alkaline pH induces death fetal fibroblast type and replacement by a profibrotic fibroblast. The patterns of intraoral fibrotic bands produced by alkaline chemical injury mimic those produced by areca nut chewing. Sharma et al., have equated the pathogenesis of<unk>  to a over-healing wound, to explain its evolution as well as malignant transformation. Increased mechanical stiffness through YAP/TAZ pathway accelerates the malignant transformation of<unk> . The atrophic epithelium in<unk>  has been attributed to the senescence of basal stem cell layer and the development of hyperplastic epithelium through senescence escape.
Oral submucous fibrosis
Dyskeratosis congenita
Zenker's degeneration
Van Buchem disease
Degos disease
Bromoderma
Keratomalacia
Kyrle disease