Thanks for asking the query,
Oral ulcerations are caused due to deficiency of vitamin B especially B3 and vitamin C
, due to traumatic incidents like self inflicted bites,hormonal imbalances and allergic reactions.
I would suggest you to visit a Dentist
and get a checkup done.
Apply cortisone acetate
cream topically over the affected area.
Avoid intake of hot and spicy food stuffs.
Maintain a good oral hygiene
Use lukewarm saline gargles 3-4 times and antiseptic mouthwash gargles twice daily.
Hope this helps out.