Ghost image of an ectopic tooth in maxillary sinus: A diagnostic challenge.

Ghost images are artefacts of anatomical structures or foreign objects that oral and maxillofacial surgeons should take into consideration to prevent misdiagnosis and mistreatment. A 38-year-old male patient referred to our clinic for dental implant treatment. Orthopantomograph (OPG) revealed an impacted distomolar at the apex of maxillary right third molar and an ectopic supernumerary tooth in the left maxillary sinus. Despite the ectopic supernumerary tooth appearance on OPG, cone beam computed tomography images revealed that there was not a supernumerary tooth in the left maxillary sinus. Nasal cavity and paranasal sinuses in field of view were evaluated and maxillary ostium diameters were measured to detect if the tooth had migrated. The tooth appearance on the OPG was determined as a ghost image of the impacted distomolar at the contralateral side. Following the extraction of the distomolar, another OPG was performed and the ghost image was disappeared.