{"title":"Three-Dimensional Analysis of Soft and Hard Tissue Changes following Orthognathic Surgery.","authors":"Yoshiko Onaga, Takashi Kamio, Takashi Takaki, Takahiko Shibahara","doi":"10.2209/tdcpublication.2020-0021","DOIUrl":null,"url":null,"abstract":"<p><p>Change in soft tissue in relation to that in hard tissue following orthognathic surgery was evaluated. Twenty-five patients were enrolled in the study. The diagnosis in all was jaw deformity (maxillary retrusion and mandibular protrusion) and all underwent a Le Fort I osteotomy and bilateral sagittal splitting ramus osteotomy. Three-dimensional (3D) computer-aided design (CAD) models (polygon models) of the hard and soft tissue of the maxilla and mandible were constructed and superimposed. Reference points were established on the pre- and postoperative hard and soft tissues. Specific elements of each reference point were divided into X, Y, and Z components, respectively, and the distances in each direction and 3D distance (normal distance) measured. The Wilcoxon signed-rank test was used to determine differences in the mean values for the distance moved of each element as the error between pre- and postoperatively. The results revealed statistically significant differences in the Y-direction in the maxilla and the X- and Z-directions in the mandible. A significant difference was also observed in the 3D distances of the maxilla and mandible. Little evidence was found of linearity between the amount of hard and soft tissue movement in the X- and Z-directions in the maxilla. This means that 3D movement in the maxilla was masked more by changes in the morphology of the soft tissue than in the mandible, making it less evident. The results of this study suggest that the 3D analysis method used enables changes in hard and soft tissues to be understood qualitatively, and that it can be used in diagnosis and treatment in orthognathic surgery. It may also be useful in simulation of morphological change in soft tissue.</p>","PeriodicalId":45490,"journal":{"name":"Bulletin of Tokyo Dental College","volume":"62 3","pages":"151-161"},"PeriodicalIF":0.5000,"publicationDate":"2021-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of Tokyo Dental College","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2209/tdcpublication.2020-0021","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/8/15 0:00:00","PubModel":"Epub","JCR":"Q4","JCRName":"DENTISTRY, ORAL SURGERY & MEDICINE","Score":null,"Total":0}
引用次数: 1
Abstract
Change in soft tissue in relation to that in hard tissue following orthognathic surgery was evaluated. Twenty-five patients were enrolled in the study. The diagnosis in all was jaw deformity (maxillary retrusion and mandibular protrusion) and all underwent a Le Fort I osteotomy and bilateral sagittal splitting ramus osteotomy. Three-dimensional (3D) computer-aided design (CAD) models (polygon models) of the hard and soft tissue of the maxilla and mandible were constructed and superimposed. Reference points were established on the pre- and postoperative hard and soft tissues. Specific elements of each reference point were divided into X, Y, and Z components, respectively, and the distances in each direction and 3D distance (normal distance) measured. The Wilcoxon signed-rank test was used to determine differences in the mean values for the distance moved of each element as the error between pre- and postoperatively. The results revealed statistically significant differences in the Y-direction in the maxilla and the X- and Z-directions in the mandible. A significant difference was also observed in the 3D distances of the maxilla and mandible. Little evidence was found of linearity between the amount of hard and soft tissue movement in the X- and Z-directions in the maxilla. This means that 3D movement in the maxilla was masked more by changes in the morphology of the soft tissue than in the mandible, making it less evident. The results of this study suggest that the 3D analysis method used enables changes in hard and soft tissues to be understood qualitatively, and that it can be used in diagnosis and treatment in orthognathic surgery. It may also be useful in simulation of morphological change in soft tissue.
评估正颌手术后软组织与硬组织的变化。25名患者参加了这项研究。所有患者的诊断均为颌骨畸形(上颌后缩和下颌前突),均行Le Fort I截骨术和双侧矢状分叉支截骨术。建立上颌、下颌骨硬、软组织的三维(3D)计算机辅助设计(CAD)模型(多边形模型)并进行叠加。在术前和术后的软硬组织上建立参考点。将每个参考点的特定元素分别划分为X、Y、Z分量,测量每个方向的距离和三维距离(法向距离)。使用Wilcoxon符号秩检验来确定每个元素移动距离的平均值的差异,作为术前和术后的误差。结果显示,上颌骨y方向和下颌骨X、z方向差异有统计学意义。上颌和下颌骨的三维距离也有显著差异。很少有证据表明,在上颌骨的X和z方向上,硬组织和软组织的运动量之间存在线性关系。这意味着,与下颌骨相比,上颌骨的三维运动更多地被软组织形态的变化所掩盖,从而使其不那么明显。本研究结果表明,所采用的三维分析方法可以定性地了解硬软组织的变化,可以用于正颌手术的诊断和治疗。它也可用于模拟软组织的形态变化。