Abstract
An abnormal tooth whose crown develops in the opposite direction is called an inverted tooth.
We report the case of a 62-year-old female patient who was detected to have an inverted tooth in the left nasal cavity. We extracted the tooth easily from the nasal cavity under general anesthesia. Pathologic examination revealed the tooth to be a supernumerary canine caused by an ectopic supernumerary dental organ. Most inverted teeth are caused by ectopic dental organs, while other causes include the remains of deciduous teeth, and damage and the displacement of the maxilla. At the beginning of the development of the palate, the sutures between the incisors and canines are not yet completely closed. When the suture is separated, the adjacent dental organ can be easily displaced; therefore, most ectopic teeth are incisors or canines. Furthermore, since closure of the suture on the left side is delayed as compared with that of the rightside, ectopic teeth are twice as common on the left side as on the right side. Some inverted teeth may never be diagnosed if they cause no symptoms. We recommend extraction of an inverted tooth as soon as it is detected, in order to prevent repeated attacks of sinusitis and formation of a cyst of the dental sac.
