OSMF May be a reason but depends on your habits too, try doing some mouth opening exercises and also try to Palpatine your check from inside and see if you have any variation like thick bands if so consult a dentist for management no need to panic. Attending upon the complaint early will help better prognosis

Hello mam Mouth restriction usually occurs after extraction of 3rd molar which settles down in a week or so. If it is not settling down there might be some soreness of the muscles. OSMF is a typical condition which affects tobacco chewers and chronic smokers. At our clinic, we diagnose the problem correctly and then treat it. Mouth opening can be improved by taking proper medicines and warm saline rinses.