Immediate Space Closure and Alveolar Bone Regeneration Through Autotransplantation: A Case Report

This case report presents the clinical and radiographic outcome of immediate autotransplantation of a mandibular third molar into an infected first molar socket, with simultaneous space closure and alveolar bone regeneration. An 18-year-old female patient presented with a severely compromised right mandibular first molar due to a periapical lesion. The tooth was extracted, and the mandibular left third molar, selected for its favorable root development stage, was transplanted into the infected site during the same surgical session. Post-operative derotation was initiated with aligners and completed with segmental fixed appliances. One year after transplantation, cone-beam computed tomography showed complete bone healing and root maturation of the donor tooth. Clinically, the tooth was functional, sensibility returned during orthodontic treatment, and no ankylosis or root resorption was observed. Autogenous tooth autotransplantation in infected sites can preserve alveolar bone and support root development. However, it may cause intraoperative pain and require subsequent orthodontic treatment, which should be discussed preoperatively.