The periodontal therapy of severely damaged teeth that have advanced bone loss, a significant degree of mobility, and often tooth migration and elongation, frequently exposes the dental clinician to difficult decisions regarding the appropriate therapy for the patient. Extensive rehabilitation, with the replacement of periodontally hopeless teeth, has biologic, prognostic, and financial limitations. A possible alternative in such cases is the transreplantation of periodontally hopeless teeth. Ankylosis of the tooth is induced by appropriate extraoral pretreatment and thus the mobility disappears and the alveolar bone is reformed. This little-known technique is described step by step, with reference to a clinical case. Schlagwörter: guided tissue regeneration, implantology, interdisciplinary treatment, periodontology, transreplantation