Sequential Double Autotransplantation Using Immature Teeth as First-Stage Autotransplants to Preserve Alveolar Architecture: A Case Series.

Introduction: Missing teeth in growing patients require treatment approaches that preserve alveolar bone and support continued development. Autotransplantation offers a biological alternative to implants, yet severely compromised recipient sites and immature donor teeth present clinical challenges. This case series describes a sequential double autotransplantation protocol using immature first-stage autotransplants to preserve alveolar architecture and exploit the osteogenic potential of periodontal ligament-derived mesenchymal stromal cells for alveolar bone regeneration. Methods: Three patients (ages 16-18 years) with severe bone defects, oroantral communication, or cystic pathology underwent planned two-stage autotransplantation. CBCT-guided planning and 3D-printed templates were used to minimize extra-alveolar time. Immature donor teeth were used as first-stage transplants to preserve alveolar architecture and periodontal space prior to definitive transplantation. Secondary transplantation with a more developmentally mature donor followed assessment at 12 months. Results: All cases achieved favorable outcomes at 24 months after second-stage autotransplantation, including pulp chamber obliteration without periapical pathology or clinical symptoms, consistent with maintained pulp vitality, continued root development, and periodontal probing depths of 2-3 mm at final follow-up. Conclusions: The primary lesson is that recipient site condition, rather than donor tooth development alone, determines prognosis in severely compromised cases, and a staged protocol can preserve alveolar architecture for definitive rehabilitation. Recipient site condition, rather than donor tooth developmental stage alone, appears to be the primary determinant of outcome in severely compromised cases. Validation through larger controlled studies remains essential.