The author presents the tase-history of an adult female patient who shortly before admission to the Stomatological Clinic observed a change of the position of tooth 11 and shortly afterwards a relatively extensive bulging of the palate behind the upper middle incisors developed. The patient saw her dental practitioner who referred her to our Clinic with the diagnosis of a maxillar cyst. Based on clinical and X-ray examination the diagnosis of a cyst of the nasopalatine duct was established. Surgery was performed under general anaesthesia, teeth 11 and 21 esere fixed by a resin splint. Histologickl examination confirmed the diagnosis. Healing proceeded without complications, both large incisors remain vítal.

        Key words: cystis ductus nasopalatini - differential diagnosis - exstirpation of cyst - minisplint