Classification<unk>  is clinically divided into three stages: *Stage 1: Stomatitis *Stage 2:<unk>  *a- Early lesions, blanching of the<unk>  mucosa *b- Older lesions, vertical and circular palpable fibrous bands in and around the mouth or lips, resulting in a mottled, marble-like appearance of the buccal mucosa *Stage 3: Sequelae of<unk>  *a- Leukoplakia *b- Speech and hearing deficits Khanna and Andrade in 1995 developed a group classification system for the surgical management of trismus: *Group I: Earliest stage without mouth opening limitations with an interincisal distance of greater than 35 mm. *Group II: Patients with an interincisal distance of 26–35 mm. *Group III: Moderately advanced cases with an interincisal distance of 15–26 mm. Fibrotic bands are visible at the soft palate, and pterygomandibular raphe and anterior pillars of fauces are present. *Group IVA: Trismus is severe, with an interincisal distance of less than 15 mm and extensive<unk>  of all the<unk>  mucosa. *Group IVB: Disease is most advanced, with premalignant and malignant changes throughout the mucosa.tumor necrosis factor alpha and keratin 17 are interdependent regulators, they could be used as diagnostic makers and a prognostic mirror of<unk>  cases
Oral submucous fibrosis
Dyskeratosis congenita
Zenker's degeneration
Van Buchem disease
Degos disease
Bromoderma
Keratomalacia
Kyrle disease