[Dysontogenetic cysts of the mouth floor].

Congenital cysts of the floor of the mouth are rarely seen. We investigated in the years 1987 and 1988 four patients with swellings in the floor in the mouth. The histological examination results dermoid and epidermoid cysts. A teratoma was not seen. Sonographic investigation and computertomography were both helpful by getting the correct diagnosis of these cysts and their location. The treatment was the exstirpation from the outside of the throat because all cysts were located under the geniohyoid muscle.