To test that callotasis can be used for ridge augmentation, the present experiments were performed in dogs. In the experimental group, ridge augmentation by callus distraction was performed; in the control group ridge was augmented in a single period. New bone formation in the distraction gap was evaluated radiographically and histologically.
In the experimental group, most of ridges were structurally stable after removal of the distraction appliances, and all of the dogs were able to eat hard pellet food.
Radiographically, radiopaque appearance could be seen throughout the distraction gap.
But the distraction gap was still less radiographically dense than the pre-existing mandible.
Histologically, in the lingual area numerous new bone formations aligned in the direction of distraction could be seen throughout the distraction gap. In the center of the distraction gap, osteoblasts could be seen around new bone formations. New bone formation bordering on the pre-existing mandible and transport disk demonstrated lamellar structure. In the buccal area a lot of fibrous connective tissue could be seen, but little new bone formation could be seen.
In the control group, most of the transport disks were widely exposed during the distraction process, and suffered from major infections.
Radiographs showed that most of the distraction gap was filled with radiolucent appearance.
Histologically, the central area of the distraction gap was filled with fibrous connective tissue, though a little new bone formation could be seen around the transport disk and preexisting mandible.
