It is Submucosal Fibrosis.
Oral submucous fibrosis (OSMF) is an oral precancerous condition characterized by inflammation and progressive fibrosis of the submucosal tissues resulting in marked rigidity and trismus.
Causative factors of OSF include autoimmunity,
vitamin B, C, and iron deficiencies, chewing betel nut, consumption of spicy foods, human papilloma virus (HPV) infection, and genetic mutations.
Next Steps
Avoid addiction including betel nut.
Take Multivitamin and Lycopene.