Tooth Autotransplantation of A Mandibular Third Molar Followed by Delayed Root Canal Treatment to Manage External Inflammatory Resorption: A Case Report.

Tooth autotransplantation (TA) is indicated in cases of structurally compromised teeth with poor prognosis when a donor tooth is available. This case report describes the TA of a mandibular right third molar (48) into the position of the mandibular right second molar (47) in a 32-year-old male patient. Clinically, extensive coronal destruction and a sinus tract were observed in tooth 47, rendering retreatment unfavorable. The tooth was diagnosed as previously treated, with a chronic apical abscess. Therefore, tooth 48 was autotransplanted into the 47 position. Four months later, apical external inflammatory root resorption was observed. However, root canal treatment was performed one year after TA because the patient did not adhere to follow-up recommendations. After two years, the tooth remained asymptomatic, with no signs of periapical lesions or periodontal changes. In conclusion, TA may serve as a viable strategy for replacing structurally compromised permanent molars, thereby preserving the function of the natural dentition.