Abstract:

BACKGROUND: Recently, Damon Ⅲ appliance is the new direction of appliance improvement.
OBJECTIVE: To investigate the histopathological changes of rabbit periodontal bone tissue under the pressure side in the remodeling process after different appliance orthodontic.
METHODS: Sixty-four healthy rabbits were randomly divided into four groups: control group, MBT appliance group, Begg appliance group and Damon Ⅲ appliance group. The MBT appliance, Begg appliance and Damon Ⅲ appliance were ligated between the maxillary incisors and first molars in order to tract the appliances move to the maxillary incisors for 1 mm.
RESULTS AND CONCLUSION: At 7 days after correction, the volume of trabecular bone in the pressure side of rabbit periodontal bone tissue was reduced, the trabecular width was narrowed and the gap was broaden in MBT appliance group, Begg appliance group and Damon Ⅲ appliance group (P < 0.05), and the amount of osteoblast and osteoclast was increased significantly (P < 0.05). At 21 days after correction, compared with MBT appliance group and Begg appliance group, the volume of trabecular bone in the pressure side of rabbit periodontal bone tissue was reduced, the trabecular width was narrowed and the gap was broaden and the amount of osteoblast and osteoclast was increased significantly in the Damon Ⅲ appliance group (P < 0.05). In the initial phase of orthodontic tooth movement, MBT appliance, Begg appliance and Damon Ⅲ of appliance have orthodontic effect, but the late effect of Damon Ⅲ appliance is better than that of the MBT appliance and Begg appliance.