Ductal variation of the sublingual gland: a predisposing factor for ranula formation.

BACKGROUND The purpose of this study was to evaluate ranula development according to anatomic variation of the sublingual gland (SLG). METHODS We conducted a prospective, consecutive case series considering other clinical conditions. Twenty-five cases treated by SLG excision were enrolled in this study. The ductal structures of the SLGs of another 11 patients undergoing similar surgeries for other conditions were compared. RESULTS In 19 of a total of 25 ranulas (76.0%) and 16 of 18 oral nonplunging ranulas (88.9%), the SLG showed an anatomic variation of the main duct called Bartholin's duct structure. Meanwhile, only 3 of 7 plunging ranulas (42.9%) had Bartholin's ducts. Bartholin's duct structure of the SLG was not found in the 11 control cases. CONCLUSION Anatomic variation of the ductal system of the SLG might be a possible cause of ranulas. Surgical resection of the SLG is a better treatment choice for ranulas than other, more conservative treatments.