Periodontal Healing After Autotransplantation of Incisors in Beagle Dogs

Objectives: Periodontal pathology such as root resorption or ankylosis.is still an unavoidable complication of autotransplanted teeth. Several reports have suggested that masticatory stimulation may improve the prognosis of autotransplantation, but a detailed understanding of the mechanism is lacking. The objective of this study was to develop an animal model of incisor autotransplantation.
Methods: Four beagle dogs about 9~11 months old with good general health were used. Totally thirty-two incisors were endodontically treated to prevent subsequent inflammatory root resorption. Then the teeth were atraumatically extracted and autotransplanted to the other side of the same jaws. Continuous 50g orthodontic force was initiated at the 1^st, 2^nd and 4^th week after autotransplantation respectively. The observation time was 8 weeks. Toleration and behavior change of animals, the mobility of teeth, maintenance of orthodontic appliances were observed. Periodontal healing were analyzed by micro-computed tomography (micro-CT) scans and histology.
Results: All the dogs tolerated the operative procedures. The survival was 93.75% (30 of 32) for autotransplanted teeth. Micro-CT revealed that all the force-loaded groups had a significantly less ankylosis in comparison with controls. But 1^st week loaded group had severe resorption than did other groups. The radiographic findings were confirmed via histology and topographical method suggested by Andersson.
Conclusions: This study describes a animal model of autotransplantation of single-root teeth. It is possible to take advantage of brackets and archwires to deliver different level of force. This model should be a useful tool to dissect mechanisms of periodontal healing of autotransplanted tooth and evaluate potential orthodontic treatment interventions.