Two cases of oral floor dermoid cysts, and proposal for the Japanese classification

Abstract

City Hospital 1.6% of dermoid cysts of the whole body occur in the oral floor. Usually in Japan, dermoid cysts in the oral floor are divided into three groups according to Hagizaki's classification : subglossal type, submental type and subglossal-submental type. Recently, we treated one patient with the subglossal-submental type of dermoid cyst and another patient with the subglossal type and submental type of dermoid cyst. In consideration of these cases, although Hagizaki's classification is helpful for deciding the surgical procedure for oral floor cysts, we had two questions regarding the classification. The first one is that the submental type, which is anatomically located outside the oral floor, is placed in the category of oral-floor dermoid cysts. The second one is that the anatomical site of the subglossal-submental type remains obscure in the existing literature regarding oral floor cysts. These issues cause confusion in the literature on oral-floor cysts. This paper proposes a revision to the Hagizaki classification to eliminate the problem.