This study was performed to investigate the effect of immediate orthodontic force on soft and hard tissues surrounding C-Palatal Platen" in beagle Dog. Immediately after this appliance was implanted on the nudpalate of 4 adult beagle Dogs, 400gm continuous orthodontic force was applied Experimental animals were euthanized at 8weeks, 18weeks, and 22weeks (including post-removal healing time of 4weeks), and a control animal was euthanized at 8weeks after implantation without orthodontic force application. The appliance and the surrounding tissue were studied radiographically, macroscopically, and histologically.
The results were as follows
1. The lateral radiographs taken after euthanasia showed very slight displacement of the vertical plate inlthe experimental animals, compared with the control animal. Mobility test of all animals confirmed primary }>tability without any increase of mobility during experimental period.
2. NQpathologic changes,were found in the healing condition of covering soft tissue and bone-screw interface in experimental ]animals ´as well as a control animal.
3. Osseointegration was achieved in the bone-screw interface in 8weeks after implantation and the amount of osseointegration increased in l8weeks. There was little difference of osseointegration between the compression side and the tension side.
4. In the marginal bone area, slight bone apposition and resorption were found regardless of compression and tension side, while there was no change in the control animal.
5. Both 8week-animal and 18week-animal showed the new bone apposition along the surface of screws which were
perforated into the nasal cavity, while the control animal showed no change.
6. After 4weeks of plate removal, the covering epithelium was repaired intactly, while the connective tissue showed
loose and irregular rearrangement and the connective tissue capsule remained.
The C-Palatal PlateTM manifested sufficient anchorage capacity in the context of histological study as well as clinical outcomes, when immediate orthodontic force was applied after implantation.
|