[Establishment of a dog model of orthodontic tooth moving into newly distracted bone]

This study was to establish an animal model of tooth moving into newly distracted bone after mandibular distraction osteogenesis in Beagle dog.

Eight Beagle dogs were selected in this study four dogs (experiment group) underwent 10 mm of bilateral mandibular distraction osteogenesis. After 0-week consolidation periods, the bilateral third premolars were moved distally into the regenerated bone with 150g orthodontic force for 8 weeks. Four dogs(control group) were extracted the fourth premolar. Twelve weeks later, the bilateral third premolars were moved distally with 150g orthodontic force for 8 weeks. The force was checked and activated weekly. The characters about the third premolar movement style, movement rate and alveolar bone remodeling were investigated by the following methods: measuring the distance of tooth movement, radiographic examination and histological examination.

The experimental procedure was well tolerated in all animals and 10 mm distraction length was successfully achieved. A dog model for tooth moving into newly distracted bone was established successfully. The rate of movement in the experimental group was faster when the teeth were moved into newly distracted bone after 0-week consolidation periods than that in the control group. We observed significant root resorption extending into the cementum with 150g orthodontic force in the group after 0-week consolidation periods.

Beagle dog is a satisfactory animal on the experimental study for tooth moving into newly distracted bone. Supported by Shanghai Leading Academic Discipline Project (S30206).