Allotransplantation of human teeth. A retrospective study of 73 transplantations over a period of 28 years.

An assessment was made of the postoperative fate of 73 allotransplanted human teeth carried out by 3 surgeons between 1956 and 1980 to determine the clinical and radiographical course of immunogenetically unmatched allotransplanted human teeth. The mean ages of recipients and donors were 34.1 and 15.2 years, respectively; 47 of the grafts had incomplete root-formation at time of transplantation. Mean observation period was 7.8 years with a maximum of 28 years. The study was terminated December 1985. The mean functional time of the grafts (function of graft without symptoms) was 6.8 years (max. 28.5 years). No signs of pulpal survival were found in any graft. Root resorption was found in 91.6% of grafts within a mean of 8.8 months after transplantation, causing a high frequency of graft loss within the first 2 years (34.1%). Recipients older than 45 years of age retained the grafts significantly longer than young patients. The major causes of graft loss were replacement (60.3%) and inflammatory resorption (24.4%). Graft loss due to marginal periodontitis was minor (2.7%). Inflammatory resorption, which was found more frequent in young recipients (P = 0.02), usually caused rapid rejection, whereas the survival time after ankylosis was significantly longer. In conclusion, no clinical or radiographical evidence of long-term survival of the pulpal or periodontal tissues of the unmatched allografts were found. However, despite a progressing replacement resorption frequently present, the allografts seem to function clinically sufficient, symptomless and often with clinically normal gingival condition for many years. Increasing age of the recipient at time of transplantation significantly increased the function time of the graft. Younger recipients showed more inflammatory resorption of the grafts.