Table 1.

Classification system of oral submucous fibrosis proposed by Passi et al (2017) (Reference No. 45).

Grading/staging	Clinical	Functional	Histopathological	Treatment	Prognosis
Grade I	Involvement of < 1/3rd of the oral cavity, Mild blanching, burning sensation, recurrent ulceration, and stomatitis,dryness of the mouth.	Mouth opening up to 35 mm.	Stage of inflammation: Fine oedematous collagen, congested blood vessels, abundant neutrophils along with lymphocytes with myxomatous changes in the subepithelial connective tissue layer of epithelium.	Cessation of habit, nutritional support, antioxidants, topical steroid ointment.	Excellent.
Grade II	Involvement of 1/3rd-2/3rd of the oral cavity, blanching, mottled and marble-like appearance, palpable fibrotic bands and involvement of soft palate and premolar area.	Mouth opening 25–35 mm, Cheek flexibility gets reduced by 33%.	Stage of hyalinization: Juxta–epithelial collagen hyalinization, lymphocytes, eosinophils, dilated and congested blood vessels, less fibroblastic activity. granulation changes in the muscle layer with reduced inflammatory cells in the subepithelial layer.	Habit cessation, nutritional supplements, intralesional injection of placental extracts, hyaluronidase, steroid therapy, Physiotherapy.	Good, The recurrence rate is low.
Grade III	Involvement of  > 2/3rd of the oral cavity. Severe blanching, broad thick fibrous palpable bands at cheeks and lips and rigid mucosa, depapillated tongue and restricted tongue movement, shrunken bud-like uvula,involvement of the floor of the mouth and lymphadenopathy.	Mouth opening 15–25 mm, Cheek flexibility gets reduced by 66%.	Stage of fibrosis: Complete collagen hyalinization without fibroblasts and oedema, obliterated blood vessels, inflammatory infiltrate mainly plasma cells and lymphocytes, extensive fibrosis with hyalinization from subepithelial to superficial muscle layers exhibiting atrophic and degenerative changes.	Surgical treatment including band excision and reconstruction, bilateral temporalis myotomy and coronoidectomy.	Fair, The recurrence rate is high.
Grade IV	Changes like leukoplakia, erythroplakia and suspicious malignant lesion.	Mouth opening < 15 mm or nil	Stage of malignant transformation: Erythroplakia changes into squamous cell carcinoma.	Surgical treatment and biopsy of the suspicious lesion.	Poor, Malignant transformation.