We analyzed the frequency and radiological features of mesiodens in a group of children in Turkey. The study was based on a radiographic review of 23,000 pediatric patients (male: 12,667 female; 10,333) who visited the Department of Oral Diagnosis and Radiology during the period 2003-2005 (3 years). The presence of an unerupted supernumerary tooth, or tooth bud between the 2 central incisors or as unilateral or bilateral teeth in the midline of the maxilla was noted as mesiodens on radiographs. Eighty-five cases of mesiodens in 69 patients were found. Complete documentation, including radiographs, for these 69 patients were studied and analyzed. In addition to gender and age, the following information about the mesiodens was recorded: 1) number; 2) shape; 3) position; 4) complications caused by the mesiodens; 5) treatment. Of the 69 patients, the ratio of boys (47 cases) to girls (22 cases) was 2.1:1. Fifty-three (76.8%) of the children had 1 mesiodens, and 16 (23.1%) had 2 mesiodentes bilaterally to the midline. Of the 85 mesiodentes, 67 (78.8%) were fully impacted, 6 (7%) were partially erupted, and 12 (14.1%) were fully erupted. Most of the mesiodentes (55.2%) were found in the vertical position, followed by inverted position (37.6%), and horizontal position (7%). The main complications were delayed eruption of the permanent incisors (38.8%), maxillary midline diastema (17.6%), axial rotation or inclination of erupted permanent incisors (16.4%), and resorption of the adjacent teeth (4.7%) The prevelance of mesiodens has been estimated to be 0.15% to 2.2% of the population.