Reasons are of ulcers.

A bite for tongue with teeth's, injuries of hard brush, irritations for tongue of meal, remedies, sharp edges of teeth, dentures and filling, but injuries ulcers are harder of a meal irritating, sour, spicy, hot, as here in small injuries aphtosis is hurt and rashing.

Ulcers also display in weak immunity, viruses, allergy of stomatitis, tiredness and necrotic gyngivostomatitis, as with bad smell mouth, salivation, high temperature, yellow grey rashes on the gums, ulcers are green, bleed, not  smooth edges, and in lung tuberculosis display tuberculosis of mouth cavity, as in entering in mouth cavity are tuberculosis bacterias, and on theirs sides are forming tuberculosis nodules, bleeding, not deep, and temperature is high, indisposition whole.

As in syphilis ulcers display on tongue, cheeks, palate, lips, healing till 4 months, and leaving scars, like a stars.

HIV  are ulcers forming on gums, tongue, lips, palate, cheeks.

And a cure ids reason finding, and kind of display, as herpetic curing with acyclovir,and on virus herpes affecting, aphtosis are antibiotics , corticosteroids, sulfanilamides, vitamin C for immunity.
In necrotic are antibiotics, anti allergy drugs, high calorie diet, vitamins, necrotic tissues doctors removing under narcosis and manufacturing with antiseptics.

Injuries of are self curing, tuberculosis at tuberculosis hospital curing for, and HIV IN INFECTIONISTS.

Manufacturing ulcer with a green, she is disinfecting, ammonia peroxide a few times/day, gels with lidocaine, dexamethason are gels, ointments, gel Cholisal, sol. chlorhexine for gargle, sol. soda, furacillini in water, and healers are best of calendula, chamomile, bark of oak, sage, hypericum, thyme, and on tongue ulcers curing timely,as against complications display.