髁突在BSSRO手术两种裂开方式不同前移量下位置变化的观测研究

发布时间：2018-06-03 20:16

本文选题：双侧下颌升支矢状劈开截骨术(BSSRO) + 有限元　；参考：《天津医科大学》2016年硕士论文

【摘要】：目的:1.运用多种软件联合建立3D仿真模型,并模拟下颌升支矢状劈开截骨(BSSRO)手术内固定后的模型。为用有限元法分析BSSRO术后不同组织结构的生物力学提供参考。2.从生物力学角度出发,观察在BSSRO手术两种裂开方式、不同前移量情况下,髁状突的位移变化趋势。更深入了解BSSRO手术后髁突位置的变化情况。3.在有限元模型上,比较分析髁状突在BSSRO手术两种裂开方式、同一前移量情况下的位移变化,以及同一裂开方式、不同前移量情况下的位移变化。为改进临床手术,避免髁突移位提供理论基础。研究对象及方法研究对象:下颌骨干骨模型,以下颌骨干骨模型为基础建立的包括髁突软骨、关节盘、关节窝的有限元(FE)模型。研究方法及步骤:1.选取并建立模型。(1)选取解剖结构完整,牙列完整的下颌骨干骨标本,作为实体模型。(2)采用CBCT扫描技术获取下颌骨连续断层的DICOM格式数据,通过数字影像转换,与三维有限元方法相结合直接建模。建立的包括髁突软骨、关节盘、关节窝在内的下颌骨3D模型。2.模拟BSSRO手术:在下颌与关节复合体三维有限元模型上,模拟BSSRO手术,使下颌骨分成两个近心骨段与一个远心骨段,并用钛板钛钉固定。骨裂方式分别为下颌后缘内外骨板间裂开(方式1)和下颌舌骨沟裂开(方式2)两种方式。3.截骨段移位方式模拟:结合临床,在下颌与关节复合体三维有限元模型上,增加边界约束及咀嚼肌载荷,模拟远心骨段前移矫治下颌后缩畸形手术方式。4.生物力学分析比较:(1)在BSSRO三维有限元模型上,记录分析髁状突在同一种裂开方式、不同前移量工况下的位移趋势及位移量。(2)在bssro三维有限元模型上,记录分析髁状突在同一前移量、不同裂开方式工况下的位移趋势及位移量。结果:1.建立包含tmj的下颌骨三维有限元模型,并模拟bssro前移手术,获得具有几何相似性及生物相似性的三维模型,为后续研究打下基础。2.获得髁状突不同部位在不同裂开方式、不同前移量下的位移。3.髁突在以方式1裂开,前移量分别为3mm和8mm时位移量比较,髁突内侧位移变化明显(p0.05)。结论:1.无论裂开方式及前移量如何,髁突的位移趋势一样,即:髁突逆时针旋转,髁突横轴延长线夹角(ica)减小。2.当以方式1裂开时,髁突内侧的位移变化与前移量有统计学差异,前移量越大,髁突内侧的位移变化越大(p0.05)。3.当以方式2裂开时,髁突位移变化与前移量无统计学差异(p0.05)。
[Abstract]:Purpose 1. A 3D simulation model was established by using a variety of software, and the model after internal fixation of mandibular ramus sagittal split osteotomy (BSSRO) was simulated. It provides a reference for the analysis of biomechanics of different tissue structures after BSSRO by finite element method. From the biomechanical point of view, the trend of condyle displacement was observed under the condition of two kinds of split modes and different forward displacement in BSSRO operation. To further understand the condylar position after BSSRO operation. In the finite element model, the displacement changes of condyle under the same forward displacement and the same split mode and different forward displacement are compared and analyzed. To improve the clinical operation, to avoid condylar displacement to provide a theoretical basis. Objects and methods: the mandibular diaphysis model, a finite element FEE model including condylar cartilage, articular disc and articular fossa, was established based on the mandibular diaphysis model. Research methods and steps: 1. Selecting and establishing model. (1) selecting the bone specimen of mandibular diaphysis with complete anatomical structure and complete dentition as entity model. (2) using CBCT scanning technique to obtain the DICOM format data of mandibular continuous section, and converting it by digital image. Direct modeling is combined with 3D finite element method. A 3D model of mandible including condylar cartilage, articular disc and articular fossa was established. Simulated BSSRO operation: in the three-dimensional finite element model of mandibular and articular complex, BSSRO operation was simulated. The mandible was divided into two proximal bone segments and one distal bone segment, and was fixed with titanium plate and titanium nail. The fracture patterns of mandibular posterior margin were interlaminar fissure (mode 1) and mandibular hyoid fissure (mode 2). Osteotomy transposition simulation: combined with clinical, in the mandibular and articular complex three-dimensional finite element model, added boundary constraints and masticatory muscle load, simulated distal bone segment forward correction of mandibular retraction deformity operation method .4. Comparison of biomechanical analysis on BSSRO 3D finite element model, the displacement trend and displacement of condyle under the same split mode and different forward displacement conditions were recorded and analyzed on the bssro 3D finite element model. The displacement trend and displacement of condyle under the same forward displacement and different split modes were recorded and analyzed. The result is 1: 1. The three-dimensional finite element model of mandible including tmj was established, and bssro forward operation was simulated. The 3D model with geometric similarity and biological similarity was obtained, which laid a foundation for further research. The displacement. 3. 3 of condyle was obtained under different dehiscence mode and different forward displacement of condyle. When the condyle was split in mode 1 and the forward displacement was 3mm and 8mm respectively, the medial displacement of the condyle changed significantly (p0.05). Conclusion 1. Regardless of the way of opening and the amount of forward displacement, the trend of condyle displacement is the same, that is, the condyle rotates counterclockwise, and the angle between the lengthening line of the transverse axis of condyle decreases by .2. When split in mode 1, there was statistical difference between the displacement of the medial condylar process and the amount of the forward displacement. The greater the amount of forward displacement, the greater the displacement change of the medial condylar process was (p0.05 路3). There was no significant difference between the displacement of condyle and the amount of forward displacement when mode 2 was split.
【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R782

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