Translational approach to tooth autotransplantation: A 27-year case study

The aim of this case report was to present a translational approach to tooth autotransplantation using jiggling forces to enlarge the periodontal ligament (PDL) space before autotransplantation, with the goal of improving treatment success and long-term survival.

A 23-year-old patient, undergoing orthodontic therapy and with an unrestorable maxillary first molar, was proposed to have a healthy and fully-erupted maxillary third molar transplanted in the socket of the first molar. Jiggling forces were applied to the third molar to enlarge the PDL space and facilitate the preservation of PDL fibers on the root surfaces during the extraction.

Jiggling forces induced hypermobility and widened PDL space of the third molar. The autotransplantation was successful and the patient was followed regularly over a 27-year period. At the 27-year visit, the patient showed optimal chewing function, oral plaque control, and absence of gingivitis. The transplanted molar exhibited periodontal health and absence of mobility. Probing depth of 5 mm and radiographic external root resorption was noted on a localized area of the transplanted tooth which had experienced traumatic and unintentional removal of PDL fibers during the extraction.

A translational approach was proposed by integrating knowledge from the fields of orthodontics, trauma from occlusion, and replantation. It validated the crucial importance of maintaining healthy PDL fibers on the root surface and demonstrated clinically the successful autotransplantation of a fully formed third molar into the socket of a first molar with a retention of 27 years.

Why is this case new information? This case provided evidence of successful autotransplantation of a molar with complete root formation. It reported the longest-term follow-up (27 years) present in the literature. Most importantly, it used a translational medicine approach to apply concepts from the fields of orthodontics and traumatic occlusion to improve the success of the autotransplantation procedure. What are the keys to the successful management of this case? Jiggling forces induced tooth hypermobility and increased the PDL space of the tooth planned for autotransplantation. In turn, they facilitated the atraumatic extraction and preservation of the PDL fibers on the transplanted tooth, improving the success of the reattachment of periodontal fibers. What are the primary limitations to success in this case? Traumatic extraction resulting in the unintended removal of PDL fibers from the tooth planned for autotransplantation, or intentional removal of PDL fibers with root planing are expected to decrease the success rate of the autotransplantation procedure. This is due to the lack of viable PDL cells necessary for reattachment.