I had, have that, but not sure if it's the same as yours. Mine is caused by a combination of things, thickening of cheek from fibrosis, biting of gum, rubbing of sharp molar, and then sometimes abscesses, probably after getting infected. Sometimes teeth can be filed down by the dentist, if so is the cause, rinsing mouth with salted warm water, brushing after eating, to reduce chance of infection or further infection or a round of antibiotics if the doctor believes it is necessary. This has been ongoing for a few years, which is finally going to be able to be addressed by teeth extractions The required HBOT has also helped.

I hope this helps.