According to the literature, such dentition anomaly as supernumerary teeth is more common in the practice of a dentist than of an otorhinolaryngologist. Clinical manifestations of this pathology in adults are less frequent than in children. Periodically, there appear descriptions of individual cases of hyperdentia, in which the tooth is located in the nasal cavity, paranasal sinuses, orbit. It is not always possible to find such a tooth on examination, therefore, additional research methods help to determine the location and pathological process in more detail. We present our clinical observation of tooth retention and ectopia in the nasal cavity and upper jaw. The diagnosis was confirmed by the data of endoscopic examination and computed tomography of the paranasal sinuses. The ectopic tooth was found before the development of pronounced local inflammation. The tooth was removed from the nasal cavity using endoscopic techniques, no communication between the nasal cavity and the oral cavity was found. The postoperative period was uneventful. On examination two weeks after the operation, no pathological changes in the nasal cavity, paranasal sinuses were found, as well as defects in the mucous membrane and bone part of the nasal cavity floor.