Fordyce granules are commonly seen on the prolabial and oral mucous membranes of adults. According to Sewerin there is a prevalence of 80% on the prolabial mucous membranes and 95% on the oral mucous membranes and reaches a peak between 20 and 29 years of age. Experienced clinicians find that these figures are too high for the South African population. In order to accept or reject this hypothesis, it was decided to determine the prevalence of Fordyce granules in a selected population of adult South-Africans of all the age groups, but mainly between 20 and 29 years of age. In this study, the prevalence of ectopic sebaceous glands (Fordyce granules) on the prolabial and oral mucous membranes of a selected South African population, was 62.07% and 57.25% in adult males and females, respectively. This is significantly lower than the prevalence reported by Sewerin. This study also revealed that Fordyce granules are mostly seen on the lips (vermillion), labial mucosa and the corresponding parts of the alveolabial sulcus. The buccal mucosa is the second most common site, and there is no significant difference in the prevalence between males and females.

Fordyce spots. A little regarded finding in the area of lip pigmentation and mouth mucosa.Laryngorhinootologie. 1995 Jun;74(6):390-2.

Sebaceous glands on the vermilion border of the lips and the oral mucosa are common in adults. Only pathologic sebaceous glands visible through the epithelium should be regarded as Fordyce's granules. The incidence of Fordyce's granules increases from childhood to adulthood, and is slightly higher in men. The most prevalent sites are the vermilion border of the lips and the buccal mucosa. Fordyce's granules usually have the same histological features as cutaneous sebaceous glands. Pathologic alterations are rare. There is no significant correlation between Fordyce's granules and systemic diseases.

Fordyce's granules in the oral mucosa of adult Israeli Jews.Community Dent Oral Epidemiol. 1986 Aug;14(4):231-2.

The prevalence of Fordyce's granules in a group of 2,462 Israeli Jews was determined. Fordyce's granules were observed in 94.9% of the entire sample. The most common location was the vermilion border of the upper lip (82.2%), followed by the retromolar area (73.3%), the buccal mucosa (65.9%) and the vermilion border of the lower lip (29.2%). The granules were common in men. A significant difference in prevalence was found between the Ashkenazi group and each of the other two ethnic groups.

Fordyce's spots: disease, heterotopia or adenoma? Histological and ultrastructural study.J Biol Buccale. 1981 Jun;9(2):109-28.

Fordyce spots are sebaceous glands without hair follicles, most often located under the epithelium of the cheek and free lip border. These glands, present in 80 to 95% of adults, according to the localization, cannot be considered as ectopic. Along the same lines, these spots are neither a disease, a lesion or an adenoma. These glands are acino-tubular and distributed in clusters. They are connected to the covering epithelium by a duct with a keratinizing stratified epithelium. By analog to what has been done in the skin, the acinous cells can be artificially classified in three groups: basal germinative cells partially differentiated intermediary cells and totally differentiated preductal cells. With PAS-Mac Manus, the peripheral cells are characterized by a reduced cytoplasm, the scarcity of organelles, as well as the presence of tonofilaments and desmosomes. The intermediary cells have a low nucleus-cytoplasm ratio. While keeping their epidermal characters, they become rich in lipid droplets of variable sizes and are closely related to numerous mitochondria. The cytoplasm of completely differentiated cells, with unrecognizable organelles, are invaded by large lipid globules. In the periacinous connective tissues, fenestrated capillaries are observed.