Systematic Analysis Of Clinical Outcomes Of Surgery-first Approach In Orthognathic Surgery In The Treatment Of Mandibular Protrusion

Aims:The purpose of this study was to determine the changes in hard tissues, soft tissues and teeth after Bilateral Sagittal Split Ramus Osteotomy (BSSRO) and orthodontic treatment for the treatment of Mandibular Protrusion. Cephalometric analysis was used to evaluate the aesthetic effects and occlusal relationships obtained.Methods:The subjects included 11 women and 9 men (aged 18 — 27 years;average,20years) with Mandibular Protrusion who underwent BSSRO. Based on a preoperative computer-aided manufacturing/design-assisted, model surgical design and an occlusal guide plate, newocclusal relationships were established for the patients. In addition, the preoperative and the end of postoperative orthodontic treatment cephalometric radiographs were systematically analyzed.Results:In all patients, the surgical incisions underwent primany healing, with no infection or osteonecrosis. Singnificant differences were observed in the preoperative and the end of postoperative orthodontic treatment values of all hard tissue and teeth parameters, except for SNA° GoGn-SN°,SE(mm), NP-FH°, SGn-FH°,OP-FH°, 1--MP°.Li-E(mm) (P>0.05); And the most obvious significant differences were seen: 1--1-°,OP-SN°,Gome-FH°,1--AP(mm), Ns-Sn-Pos°, Ns-Prn-Pos° (P<0.05); SNB°, SND°, ANB°,1_-NA°, 1_-NA(mm), 1--NB(mm),1--NB°, Po-NB(mm), NA-PA°, AB-NP0, 1--OP°, Ui-E(mm),and S-N’-B’ ° (P<0.001).Conclusion:Postoperative follow-up lasted for 10 to 12 months.All patients eventually achieved normal downjaw relationship, tooth arch forms, and spee curves. There were no evident irregularities of teeth arrangement or abnormal occlusal relationships were observed. All patients were satisfied with their facial appearance and occlusal relationships at the end of postoperative orthodontic treatment. We found a precise preoperative model surgical design combined with postoperative orthodontic treatment is a simple and time-saving technique. It can be used to correct Mandibular Protrusion with satisfactory occlusalrelationship, facial appearance and minimal postoperative complications.