Department of Oral and Maxillofacial Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
School of Dentistry, College of Oral Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Biomed Res Int. 2018 Dec 18;2018:1375085. doi: 10.1155/2018/1375085. eCollection 2018.
This study investigates the differences in the lateral profile and frontal appearance after sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) procedures for the correction of mandibular prognathism.
Sixty patients (30 SSRO and 30 IVRO) underwent mandibular setback surgery. Serial cephalograms were obtained: (1) T1: approximately 1 month before surgery; (2) T2: at least 6 months after surgery for SSRO and at least 1 year after surgery for IVRO. The landmarks, linear distances, and related angles were measured. The -test was applied to the intragroup and intergroup comparisons. The null hypothesis was that SSRO and IVRO made no difference in the facial appearance.
In the IVRO group, the ramus and gonial widths significantly decreased by 3.9 mm and 5.8 mm, respectively. SSRO significantly reduced the gonial angle by 2.6°, and IVRO increased it significantly by 5.3°. The postoperative increases at frontal bone levels 0 and 1 after IVRO were significantly larger than those after SSRO, but, at level 3, the increases after SSRO were larger than those after IVRO. In the frontal muscular and facial planes, SSRO and IVRO presented no difference. The frontal jaw angle and face angle were significantly larger with IVRO than with SSRO. Therefore, the null hypothesis was rejected.
The ramus width and gonial width were significantly decreased in IVRO compared to SSRO. IVRO increased angles in the lateral profile (gonial angle and mandibular plane angle) and frontal appearance (jaw angle and face angle) more than SSRO did.
本研究旨在探讨矢状劈开下颌骨截骨术（SSRO）和口内垂直下颌骨劈开截骨术（IVRO）治疗下颌前突的侧貌和正面外观差异。
60 例（30 例 SSRO 和 30 例 IVRO）患者接受下颌后退手术。获得连续头颅侧位片：（1）T1：术前约 1 个月；（2）T2：SSRO 术后至少 6 个月，IVRO 术后至少 1 年。测量标志点、线性距离和相关角度。应用 t 检验进行组内和组间比较。零假设是 SSRO 和 IVRO 在面部外观上没有差异。
在 IVRO 组中，下颌支和下颌角宽度分别显著减少 3.9mm 和 5.8mm。SSRO 显著减小了下颌角 2.6°，IVRO 显著增加了 5.3°。IVRO 术后额骨 0 级和 1 级水平的增加明显大于 SSRO，而在 3 级水平，SSRO 的增加大于 IVRO。在正面肌肉和面部平面上，SSRO 和 IVRO 没有差异。IVRO 的正面颌骨角和面部角明显大于 SSRO。因此，零假设被拒绝。
与 SSRO 相比，IVRO 中下颌支宽度和下颌角宽度明显减小。IVRO 增加了侧面轮廓（下颌角和下颌平面角）和正面外观（颌骨角和面部角）的角度，比 SSRO 更多。
