• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.6
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• pp.628-634
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• 2008

The purpose of this study is to examine reproducibility of operation plan and 3-dimentional jaw movement patterns by comparing jaw position of STO with post-operative jaw position. Twenty patients with class III dental and skeletal malocclusion who were treated with Le-Fort I osteotomy and B-SSRO were reviewed. Lateral cephalometric radiographs were taken within two weeks before operation and two days after operation. Cephalometric radiographs were compared and analyzed with orthognathic computer program '$V-Ceph^{TM}$'. Post-operative maxillary advancement was insufficient compared to maxillary advancement through STO. Post-operative setback movement was over compared to mandibular setback movement through STO. But statistically this is not significant. Maxillary vertical location is insignificant on the whole. Especially post-operative maxillary clockwise rotation is significant compared to maxillary rotation through STO. Post-operative maxillary clockwise rotation tendency is generally observed in all patients. So surgeons and staffs must consider this tendency when operation plan is established ans operation is being performed. Using intra or extra oral marking points, face bow, and bite plate will make exact surgery possible.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.4
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• pp.323-330
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• 2011

Purpose: The present study examined the reproducibility of an operation plan by comparing the jaw position of STO with the postoperative mandibular set back measurement in sagittal split ramus osteotomy. Methods: Thirty patients with class III dental and skeletal malocclusion and who were treated with BSSRO were reviewed. Three plain radiographs such as the panoramic view, the lateral cephalogram and the submentovertex view were taken before and after operation. Also, paper surgery for STO and model surgery were used to evaluate the amount of mandibular set back. Results: On the panoramic view, the amount of mandibular set back in STO was similar to the postoperative results of model surgery, but the amount of mandibular set back on the lateral cephalogram was smaller than the postoperative result of model surgery and then the amount of set back on submentovertex view was similar to the postoperative result of model surgery. Conclusion: Precise tracing and paper surgery should be performed for a combined expected STO in order to predict the exact amount of preoperative mandibular set back.