Orthodontic-Autotransplantation Treatment For A Non-Restorable Mandibular Molar Case

Introduction: Autotransplantation combined with orthodontic mechanics improves graft survival by optimizing donor positioning. This case illustrates a stepwise approach integrating pre-surgical orthodontic preloading, intraoperative non-rigid fixation, and post-transplant alignment. Case description: A 28-year-old patient presented with a non-restorable mandibular first molar (46) due to caries/apical pathology. Orthodontic examination revealed Class I left/Class II right molar relationships, 5mm lower anterior crowding (increased Bolton ratio), elongation of maxillary first premolar (15), and erupted third molar (38) suitable for transplantation. Pre-surgical orthodontics (extraction of 41) resolved crowding and normalized Bolton ratio. Conventional archwires aligned teeth; distalization of 47 via push coil spring created space for 38. A 100g force via NiTi wire preloaded the donor tooth, adjusting root angulation. A 3D-printed replica reduced donor tooth extra-oral time, preserving periodontal viability. Atraumatic extraction of 46 was followed by retrograde filling. The donor tooth was positioned into the socket and secured with brackets/wire, allowing micro-mobility. Three months post-transplant, tooth 38 was integrated into the orthodontic system, achieving ideal Bolton ratio at 1-year follow-up. Discussion: Traditional rigid fixation risks periodontal trauma. Our preloading minimized surgical adjustments and preserved ligament viability. Non-rigid fixation with brackets allowed micro-mobility, aiding physiological adaptation. The 3D replica reduced handling time, enhancing graft survival. Conclusion/clinical significance: This approach preserved bone, avoided implant placement, and achieved functional aesthetics. Combining pre-surgical force application and non-rigid fixation improved survival and reduced treatment time, offering a viable alternative to conventional methods.