Accessory branch of canalis sinuosus mimicking external root resorption: A diagnostic dilemma

The aim of this study was to recognize the importance of canalis sinuosus in Endodontics. A 60-year-old male patient reported with the chief complaint of pain and swelling in upper front tooth region for 2 weeks with a history of trauma 21 years back. Clinical examination revealed fractured tooth 21 (maxillary left central incisor) with an associated sinus tract. Radiographic examination revealed diffuse periapical radiolucency in relation to tooth 21 and external resorptive defect in apical third of the root of tooth 11 (maxillary right central incisor). Cone-beam computed tomography advised to plan surgical treatment for the same disclosed the presence of an anatomic variation of canalis sinuosus. The location and course of this canal illuded as a resorptive defect, which is a very rare occurrence. This led to a change in diagnosis with relation to tooth 11 and treatment plan was formulated accordingly.