White lesions due to subepithelial change have normal overlying epithelium, but changes in the connective tissue partially mask blood vessels and cause the area to appear white, yellow or tan. These lesions have a smooth translucent surface, do not rub off, and are not painful.
Congenital keratotic cyst* is also known as dental lamina cyst of the newborn. This is an epithelial inclusion cyst found on the attached alveolar mucosa of infants. It presents as an asymptomatic white thickened surface lesion. Similar cysts occur on the hard palate. No treatment is necessary as the lesions resolve spontaneously within several weeks after birth.
Fordyce granules* appear as flat or slightly elevated, yellow clusters, most commonly on the buccal mucosa and lip. They represent sebaceous glands. Fordyce granules are harmless and require no treatment.
Scarring (subepithelial fibrosis) of the oral mucosa can appear as white surface lesions with a smooth surface. They are non-painful and do not rub off. Diagnosis is made by history of trauma or surgery to the area. No treatment is necessary.