ObjectivesThe aim of this retrospective study is to investigate the prevalence, three-dimensional positions and supplementary findings of the presence of a mesiodens by using cone-beam computed tomography. Material and MethodsA total of 5000 cone-beam computed tomography (CBCT) scans, taken between December 2015 and March 2018, from the archive of Istanbul University Faculty of Dentistry Department of Oral and Maxillofacial Radiology, were screened. In sum, 2003 CBCT scans fulfilled inclusion criteria in this study. In addition to number of mesiodens, age and sex of the patients, shape, eruption status and direction, findings of the presence of a mesiodens were also recorded. Mesiodentes were classified according to their positions in frontal, sagittal and axial planes.ResultsIn this study, the prevalence of mesiodens was found 5.04% and to be more frequent in males than in females with the ratio of 1.9 : 1. One hundred thirty maxillary mesiodentes were detected in 101 cases out of 2003 CBCT scans. In 77 cases (76.2%), single mesiodens; in 19 cases (18.8%), two mesiodentes; and in 5 cases (4.9%), three mesiodentes were found. According to our classification, mesiodentes were mostly found in between midlines of central incisors (both the crown and root of mesiodens) in frontal plane, impacted and in contact with central incisors in sagittal plane, anterior to nasopalatine canal and in contact with nasopalatine canal in axial plane.ConclusionsCone-beam computed tomography provides more detailed information about position, neighbouring anatomic structures, and local findings of the presence of mesiodentes in multiplanar sections.