Accidental biting of the tongue, lip, or cheek is quite common and happens to all of us every now and then. No real treatment is necessary for these bites however, except for very severe bites, in which case you should rush to a doctor as soon as possible. This is usually the case only with falls and other accidents, where the impact may cause the tongue to be bitten with great force, causing a deep or wide cut and lots of bleeding.
As long as this is not the case, there is no need to worry and no need for medical treatment. Such cuts heal on their own within a few days, and even if an ulcer forms, it will heal within a week or ten days. To minimize the chances of an ulcer forming, you should be more careful about oral hygiene for the next week or so. Brush your teeth twice a day and rinse with mouthwash each time. You can also use a salt water rinse, which will prevent infection and is also quite soothing if the water is warm. Immediately after you bite yourself, ice usually helps to numb the pain, and you can use ice for a few more days too.
answered by M W