Hamadan University of Medical Sciences Avicenna Journal of Dental Research 2423-7582 9 1 2017 03 01 Epidemiological Status of Third Molars in an Iranian Population e28250 e28250 10.5812/ajdr.28250 EN Mahnaz Sheikhi Mitra Karbasi Kheir Mohammad Ali Sadeghi Journal Article 10.5812/ajdr.28250 2015 02 24 2015 05 31 Background: Impaction of third molars is a common phenomenon. The incidence of impacted third molars varies in different populations. Objectives: The aim of this study is to assess radiographic status (root development degree, angulation, and eruption level) of the third molar in Iranian population via panoramic radiographs. Patients and Methods: 647 patients, ranging in age from 17 - 25, were selected from three regions of Iran. Based on their panoramic radiographs, their root development degree, angulation, and eruption levels were analyzed. Results: The angulation of upper third molars were vertical (44.6%), distoangular (44.1%), mesioangular (10.7%), and horizontal (0.6%). For lower third molars, the angulation was mesioangular (44.5%), vertical (33.8%), distoangular (12.2%), and horizontal (9.5%). The eruption levels of maxillary third molars were C > A> B, and for mandibular third molars they were A > B> C. The order of root development prevalence of the maxillary and mandibular third molars was complete > 2/3 > 1/3. Conclusions: The most common status of impaction of the third molars in the maxilla was vertical angulation, level C of eruption, and complete root formation. In the mandible it was mesioangular, level A of eruption, and complete root formation. Since the study sample consists of patients from the north, middle, and south of Iran, the sample can represent the whole population of Iran.