Oral mucoceles; extravasation cysts and retention cysts. A study of 298 cases.

Oral mucoceles can be divided in two different forms, extravasation and retention cysts. The aim of this study was to identify the frequency of each form, sex- and age distribution, location, recurrences, referent and the differences between the two forms. A total of three-hundred-five cases were retrieved from the Department of Oral Pathology at the Institution of Odontology, The Sahlgrenska Academy at Göteborg University between 1993 and 2003. Seven referrals were disregarded because there was insufficient information, leaving 298 cases for this study. In relation to other studies, our study investigated a larger number of cases. Extravasation cysts were the most common type (258 cases). There was a slight predominance among women (55%) and the most frequent location was the lower lip (71%). 84% occurred between the ages of 0 and 40 years with peak incidence in the second decade (34%). 62% of the referrals came from specialists, 28% from general practitioners, and 10% from the Department of Oral Medicine. Retention cysts were not found as frequently as extravasation cysts (40 cases) and the occurrence in women was also a bit higher (58%). We found a more even distribution regarding age and location. The most common locations were floor of the mouth (25%), cheek (20%), and lower lip (18%). They occurred more often between the ages of 11 and 30 (31%), and between 50 and 80 (50%). 75% of the referrals came from specialists, 15% from general practitioners,and 10% from the Department of Oral Medicine. Recurrences were unusual for both cyst types. 17 cases of extravasation cysts were reported as recurrences and one case of retention cyst.