Small white granules on the mouth may be leukoplakia, lichen planus, and labiitis. 1. white spots or flat moss is a common disease in oral mucosa department, there will be white patches or granules on the lip mucosa. 2. labiitis, there will be blisters or edematous patches on the lips, it is an inflammatory disease of the lips. 3. Hand, foot and mouth disease, which occurs in the hands, feet and mouth. It is mainly characterized by papules or herpes. 4. Herpes on the lips and lips appear in the lips or the surrounding skin aggregated small blisters, may also be accompanied by fever, fatigue, sore throat and so on. There may be many reasons for white particles on the mouth, which can be checked by a dentist.