Ulcers can be caused due to the following reasons :
• Constant cheek bite
• Injury from toothbrush/sharp food particle
• Rubbing against sharp edges of the teeth around the ulcer
• Hot food
• Side effects from mouthwashes/medications
• Stress
• Gut issues
• Underlying conditions/diseases
Next Steps
Do show it to a dentist to get to the root cause of the same & to rule out everything.
Health Tips
In the meantime, keep the mouth clean by brushing twice & flossing, apply turmeric+ghee paste on the ulcer 2-3 times a day along with lukewarm salt water gargles through the day, avoid spicy & hot food till it heals & continue taking multivitamins daily along with a balanced diet.