The purpose of this study was to observe the tissue response to the orthodontic force applied immediately after buccall horizontal subapical osteotomy of maxilla
Five mongrel cats weighing about 2.5 Kg were used for this experiment. The left upper canine and premolar of each cat served as a experimental side and the right ones as a control side. On the experimental side, a 1009M orthodontic force was applied between the upper canine and premolar immediately after the osteotomy. On the control side, the same orthodontic force was applied without the osteotomy. After 7days, the experimental animals were sacrificed.
Ile results were as follows :
1. In the pressure zones of the experimental group, significant increase of osteoclasts and direct resorption along
the alveolar bone surface was -observed as compared with those of the control group.
2. In the pressure zones of the experimental group, a less extensive hyalinized zone was observed than those of
the control group.
3. In the pressure :cones of both group, no not resorption was found.
4. In the tension zones of the experimental group, new bone deposition increased along the alveolar bone surface as compared with those of the control group.
In conclusion, the results suggest the possibility that early orthodontic treatment after orthognathic surgery may have some benefits if the stability of do repositioned segment at surgery is secured.
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