he oral mucosa is biologically subdivided into keratinized (gingiva and palate), non-keratinized (lips, cheeks and ventral tongue) and specialized due to the function of taste (dorsal of the tongue) What are oral effects of COVID-19? Oral manifestations included ulcer, erosion, bulla, vesicle, depapillated tongue, macule, papule, plaque, pigmentation, halitosis, whitish areas, hemorrhagic crust, necrosis, petechiae, swelling, erythema, and spontaneous bleeding.