Comparison of the relationship between the calsification degrees of second premolar and the other permanent teeth in preschool children using three different dental age estimation methods

Congenital missing teeth are the most commonly seen in the second premolars. The dental images on the radiographs are not clear in the early childhood period. In this study, the calcification degrees of second premolars were compared with the calcification degrees of other permanent teeth. The aim of this retrospective research is to base the relationship between calcification degrees of these teeth on qualitative measurements. In our study, dental panoramic radiographs of 6813 children, who were 42-78 months, without any systemic disease affecting bone and teeth development, without any developmental disorder or oligodontia, were evaluated by 2 researchers using 3 different dental age estimation methods (Nolla method, Demirjian, Goldstein and Tanner method and Moorrees, Fanning and Hunt method). As a result of this research, while the second premolars are still at the stage of follicle formation, 4 permanent first premolars are seen at the stage where one third of the crown length is completed, the crown developments of the maxillary permanent first molars are at the stage of completion, the mandibular permanent first molars are at the stage of completing the crown development, and it has been observed that permanent second molars are in the phase when follicles are selected, and mandibular permanent second molars are in the phases where calcified points begin to form. If the follicle of the second premolar teeth cannot be detected on the radiographs while the other permanent teeth are at the above mentioned stages, the absence of second premolar teeth should be suspected, but it should be kept on mind that delayed calcification are common, thus longitudinal investigations with follow-ups including x-rays are needed to be sure.