[Current diagnosis and therapy of cysts of the mouth floor].

Cystic tumors of the floor of the mouth are relatively rare. Until today the exact localisation of the cysts in relationship to the muscles of the floor of the mouth is established mainly during operation. Therefore the preoperative decision for the optimal surgical approach can be difficult, at least in large space occupying lesions. In the present study the case of a 24-year-old female patient with an extensive dermoid cyst of the floor of the mouth is demonstrated. The preoperative use of magnetic resonance imaging enabled us to determine the exact localisation of the cyst in relationship to the muscular structures of the floor of the mouth. The differential diagnosis of dermoids of the floor of the mouth as well as the adequate therapeutic approach is discussed according to the relevant literature.