In this retrospective study, a total of 550 OPGs were assessed for Endodontically treated posterior teeth. The data obtained was obtained from an extensive electronic online database. A cross-verification was done with the clinical data for RC treated posterior in orthodontic patients. The prevalence of endodontically treated posteriors was 8.7% in the orthodontic population. Mandibular first molars accounted for nearly 46% of total root-canal treated posterior teeth, followed by maxillary first molar. A significant difference was found between males and females with and without RC treated posteriors. Males have more endodontically treated posteriors than females (p>0.1). A significant percentage of orthodontic patients have RC treated posteriors. Mandibular first molars are the most frequently endodontically treated posteriors treated posterior must be carefully assessed before orthodontic treatment as anchorage demands are high on these teeth. To obtain physiologic and successful treatment, altered treatment mechanics and treatment protocols have to be incorporated.