Hello 1)Mention your history in detail.. 2)Pain or not 3)How many day 4)Is it appeare frequently or first time 5)Is it respond to any treatment 6)What treatment you gone through for that 7)Have you bite your toung. 8) your oral habit. 9) is it changing any colour. But at first look is looks like ulcer. Use mouth wash it will healp.

How long is this ulcer in ur mouth ?? Kindly upload a  better picture of it . I m oral medicine  and radiologist ,deals all such cases . U can contact me on my page or videoconsult .

It looks like an ulcer. It can be traumatic ulcer or aphthous ulcer. Please visit a certified dentist to get it checked. Ulcers usually heal in a few days to weeks time. But cause of the ulcer should be addressed. Take care, stay safe

This is most probably traumatic ulcer from sharp edeges of teeth. Nothing to worry. Visit a dentist for smoothening of sharp edeges of teeth.