Autotransplantation of premolars to premolar sites. A long-term follow-up study of 40 consecutive patients.

This article describes the long-term outcome of 40 consecutive patients having transplanted premolars. The objective of this ongoing study is to investigate survival rate, pulp survival rate, periodontal condition, and root development of autotransplanted premolars in orthodontic patients. This report covers 17 years; 32 orthodontic patients had 40 premolars transplanted into contralateral or opposing jaw quadrants where a premolar was missing. The teeth were examined systematically with clinical and radiographic measures at 1, 2, 6, 12, and 60 months or more after autotransplantation. The observation time varied from 2 years 5 months to 22 years 3 months, with a mean of 10 years 4 months. Bonded.018-in edgewise appliances were used, subjecting 87.5% of the transplanted teeth to normal orthodontic forces. One tooth was removed because of root fracture during the observation period, and 2 more had complications possibly related to the transplantation. The remaining 37 teeth and their supporting structures were all healthy at the last examination--a 92.5% success rate. Transplants with closed apices received endodontic therapy, but, in those with open or half-open apices, a 66% pulp survival rate was observed. No teeth in the sample had signs of replacement resorption or developed periodontal attachment loss. Inflammatory resorption in 2 teeth was arrested after endodontic treatment. Root formation, when not complete, continued on transplanted teeth, giving normal root form and adequate root length for normal function. It is concluded that autotransplantation of premolars combined with orthodontic treatment should be the first treatment alternative in cases of missing premolars, when a suitable donor tooth is available.