Thanks for writing to us.
Mouth ulcers called as aphthous ulcer are usually caused by either vitamin B12
& folic acid
deficency, trauma while brushing teeth, accidentally biting while eating, allergic reaction
, poor oral hygiene
Try to regularly use mouthwash. Brush your teeth twice a day, Use soft toothbrush to aviod trauma during brushing. Take multiviatamin supplements.
Regularly follow this & than you will not develop this ulcers again.