Hi.. Welcome to HEALTHCARE MAGIC.. As per your complain the symptoms of tightening of the jaw along with reduced bulging of cheeks on blowing and ulceration or sores formation of cheeks on eating spicy foods are pointing towards a condition known as Oral Submucous Fibrosis in which there is formation of thick fibrous bands under the mucosa of cheeks leading to difficulty in mouth opening as well as reduced opening of mouth.. Tobacco intake also causes atrophy of the mucosa of cheeks leading to inflammation and ulceration as well as burning on taking even little amount of chillies or spices.. It is a pre cancerous condition and if not taken care of it can turn into oral cancer.. You should immediately stop the intake of even a little bit of tobacco and needs complete withdrawal.. Consult an Oral Physician and get evaluated and in case of oral submucous fibrosis the physician can advise you to do topical application of Steroid based ointment like Kenacort to reduce inflammation and burning and hyluronidse containing ointment as it helps in breaking the fibres.. Intra-lesion injections of a combination of steroid and hyluronidase can be injected under the mucosa directly over the fibres.. Anti-oxidant like Lycopene can be taken daily.. Gargle with a numbing mouthwash to relieve pain and burning.. Mouth opening exercises like trying to open the mouth under pressure can help.. Blowing of the cheeks as much as possible and trying to protrude the tonge out of the mouth are a few common exercises.. Avoid spicy food.. Hope this information helps.. Thanks and regards.. Dr.Honey Nandwani Arora.