正颌手术对骨性下颌后缩颞下颌关节生物力学影响的三维有限元研究
发布时间：2018-08-03 18:32
【摘要】：目的:骨性下颌后缩主要表现为Ⅱ类骨性错牙合,影响着患者口腔颌面部的功能和容貌。成年患者常需通过正畸—正颌联合治疗以获得个体最佳的咬合状态与协调的颌面部软组织轮廓。大量研究表明正颌手术与颞下颌关节(temporomandibular joint,TMJ)关系密切,正颌手术对TMJ健康的影响一直是学术界关注的问题,但至今仍未形成统一的结论。有限元法(finite element method,FEM)因具有直接实验分析无法比拟的优势而在口腔生物力学的研究中得到了大量应用。本实验通过利用三维建模软件与有限元分析软件建立骨性下颌后缩正颌手术前后TMJ与下颌及其咀嚼肌系统的有限元(finite element,FE)模型,利用有限元法基本明确正颌手术对TMJ生物力学的远期影响。方法:选取1例全口牙正畸去代偿完成时且已诊断明确的单纯骨性下颌后缩的健康成年男性患者,其头颅经16层X射线电子计算机断层扫描装置扫描获得颌面部CT平扫+三维重建的DICOM格式数据,综合运用Mimics、Geomagic Studio、Unigraphics NX,去除模型中除下颌骨及其上面的牙齿、双侧关节窝、颞骨以外的图像,并将模型从正中矢状剖开,取一侧(左侧)进行研究,在该半侧模型各临床牙根的表面建立0.2mm厚的牙周膜、在髁突头与关节窝表面分别建立0.3、0.5mm厚的软骨、根据髁突头与关节窝之间的间隙生成关节盘,将模型中的髁突划分为前斜面、横嵴、后斜面、髁突颈4个区域、将关节窝划分为前、后、中央、内侧、外侧5个区域,在模型上标记出咬肌、颞肌、翼内肌、翼外肌的附着区并确定的肌力方向,将此模型记为术前模型。在以上软件中,将术前模型模拟下颌支矢状劈开前徙术且取出接骨板、螺钉后骨不连续区完全愈合时的状态,下颌前徙距离设定为临床常用的4、8、10mm,保持肌肉附着区不变,原肌力的方向随肌肉附着区位置的变化而变化并成为最终的肌力方向,并根据髁突头与关节窝之间的间隙重新生成新的关节盘,其对应的模型分别为术后模型1、2、3。在workbench中对术前模型与术后模型1、2、3各结构的接触类型、界面类型、摩擦系数进行设定并完成四面体网格划分,设置固定约束、部件材料属性后,按最大咀嚼肌力状态设置咀嚼肌力的大小及其作用于模型的区域。结果:1.成功建立了术前与下颌前徙4、8、10mm且取出接骨板、螺钉后不连续区完全愈合时的tmj、下颌及其咀嚼肌系统的fe模型,与真实的tmj与下颌具有较好的几何相似性,网格划分比较细致,更能反映其受力时的真实状态。2.成功获得骨性下颌后缩正颌术前与下颌前徙4、8、10mm且取出接骨板、螺钉后不连续区已完全愈合时在最大咀嚼肌力状态下tmj的vonmises应力分布云图与各结构各区域的最大vonmises应力值。术前术后髁突vonmises应力最大区均位于髁突颈部后内侧,当下颌前徙4mm时,最大vonmises应力最大,为106.26mpa。在髁突头vonmises应力最大区位于前斜面与颈部交界的外侧,当下颌前徙8mm时,其最大vonmises应力最大,为21.898mpa。正颌手术前后关节窝最大vonmises应力均位于前区,当下颌前徙10mm时,最大Von Mises应力最大,为15.729MPa。随着下颌前徙距离的增加,关节窝后区与外侧区Von Mises应力有明显的增加。在下颌前徙过程中,横嵴、髁突后斜面、关节窝中央区最大Von Mises应力变化幅度较小。关节窝内侧区在下颌前徙从4mm到8mm时最大Von Mises应力增加的幅度较大。下颌前徙距离从8mm到10mm时,髁突颈部的最大Von Mises应力减小幅度较大。髁突总体Von Mises应力值明显大于关节窝。结论:综合运用Mimics、Geomagic Studio、Unigraphics NX、Workbench可建立具有较好几何与力学相似性的骨性下颌后缩正颌手术前后TMJ与下颌咀嚼肌系统的FE模型。骨性下颌后缩及其正颌术后髁突颈一直是TMJ应力最集中的部位,髁突前斜面均是髁突的主要功能面。在一定范围内,随着下颌前徙距离的增加,关节窝后外侧区域与髁突的相应接触面积逐渐增大,其应力逐渐增大。从远期来看,规范的正颌手术一般不会对骨性下颌后缩患者的髁突与颞下颌关节窝产生不良影响。
[Abstract]:Objective: the main manifestations of skeletal mandibular retraction are type II orthodontic occlusion, which affect the function and facial features of the oral and maxillofacial areas. Adult patients often need orthodontic and orthognathic therapy to obtain the best occlusion and coordinate the soft tissue profile of the maxillofacial region. Ar joint, TMJ) is closely related. The effect of orthognathic surgery on the health of TMJ has been a concern in the academic world, but it has not yet formed a unified conclusion. The finite element method (finite element method, FEM) has been widely used in the study of oral biomechanics because of the incomparable advantages of direct experimental analysis. This experiment uses three. The finite element (finite element, FE) model of TMJ and mandible and its masticatory muscle system before and after orthodontic mandibular orthognathic operation was built with the software of dimensional modeling and finite element analysis. The long term effect of orthognathic surgery on the biomechanics of TMJ was clearly defined by the finite element method. Method: 1 cases of orthodontic orthodontics were selected to complete and have been diagnosed clearly. A healthy adult male with simple osseous mandibular retraction is scanned by 16 layers of X ray computed tomography to obtain the DICOM format data of CT plain and three-dimensional reconstruction of the maxillofacial region, combined with Mimics, Geomagic Studio, Unigraphics NX, and the removal of the mandible and its upper teeth, bilateral joint fossa, and the temporal bone. The model was removed from the median sagittal and one side (left) was studied. The 0.2mm thick periodontal membrane was established on the surface of the clinical root of the half side model. The 0.3,0.5mm thick cartilage was established on the surface of the condyle head and the joint fossa, and the condyle in the model was divided into the anterior condyle according to the gap between the condyle head and the joint fossa. The 4 regions of the oblique, transverse, posterior, condylar neck were divided into 5 regions: the anterior, the central, the medial, and the outside. The model was marked with the masseter, the temporalis, the intramuscular and extragarial muscles and the direction of the muscle strength. The model was recorded as the preoperation model. The position of the mandibular anterior migration is set as a clinical common 4,8,10mm, which keeps the muscle attachment area unchanged. The direction of the original muscle force varies with the position of the attachment area of the muscles and becomes the ultimate direction of the muscle force, and regenerates a new one according to the gap between the condyle head and the joint fossa. The corresponding models are the model 1,2,3. in workbench for the contact type, the type of interface and the coefficient of friction in the model of 1,2,3 in the post operation model, the type of interface and the coefficient of friction to set the tetrahedral mesh, set the fixed constraints, and set the masticatory muscle strength according to the maximum masticatory muscle state after the material properties of the component and the size of the masticatory muscle strength. Results: 1. the results were as follows: 1. the TMJ, the FE model of the mandible and the masticatory muscle system of the mandible and the masticatory muscle system were successfully established before and after the operation and the mandibular migration, and the FE model of the mandible and the masticatory muscle system had better geometric similarity with the real TMJ and the mandible. 2. the vonmises stress distribution and the maximum vonmises stress value of the vonmises stress distribution of TMJ under the maximum masticatory muscle force in the discontinuous region of the mandible were successfully obtained before and after the maxillary mandibular retrusion, and the maximum vonmises stress in the condyle was located in the neck of the condyle. The maximum vonmises stress is maximum when the mandible moves forward 4mm. The maximum vonmises stress in the condyle head is located on the outer side of the front of the anterior oblique and the neck of the neck. When the mandible migrations 8mm, the maximum vonmises stress is maximum. The largest vonmises stress in the joint fossa before and after the 21.898mpa. orthognathic operation is located in the anterior region, when the mandible migrations before 10mm, The maximum Von Mises stress is maximum, and the stress of Von Mises in the posterior and lateral area of the joint fossa is obviously increased with the increase of the mandibular migration distance. In the process of the mandibular migration, the transverse ridge, the posterior oblique surface of the condyle, the maximum Von Mises stress in the central area of the joint fossa are small. The maximum Von of the medial section of the fossa fossa from 4mm to 8mm is migrating before the mandible. Mises stress increased greatly. The maximum Von Mises stress of the condyle neck decreased greatly when the mandibular forward migration ranged from 8mm to 10mm. The overall condyle Von Mises stress value was significantly greater than that of the articular fossa. Conclusion: the comprehensive use of Mimics, Geomagic Studio, Unigraphics NX, can establish a better geometric and mechanical resemblance to the bone. The FE model of the TMJ and the mandibular masticatory muscle system before and after maxillary orthognathic operation. The mandibular retrusion and the condyle neck of the mandibular condyle after orthognathic operation are the most concentrated parts of the TMJ stress. The anterior condylar surface of the condyle is the main functional surface of the condyle. In the long term, normal orthognathic surgery generally does not have a bad effect on the condyle and the temporomandibular fossa in the patients with skeletal mandibular retraction.
【学位授予单位】：西南医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R783.5
[Abstract]:Objective: the main manifestations of skeletal mandibular retraction are type II orthodontic occlusion, which affect the function and facial features of the oral and maxillofacial areas. Adult patients often need orthodontic and orthognathic therapy to obtain the best occlusion and coordinate the soft tissue profile of the maxillofacial region. Ar joint, TMJ) is closely related. The effect of orthognathic surgery on the health of TMJ has been a concern in the academic world, but it has not yet formed a unified conclusion. The finite element method (finite element method, FEM) has been widely used in the study of oral biomechanics because of the incomparable advantages of direct experimental analysis. This experiment uses three. The finite element (finite element, FE) model of TMJ and mandible and its masticatory muscle system before and after orthodontic mandibular orthognathic operation was built with the software of dimensional modeling and finite element analysis. The long term effect of orthognathic surgery on the biomechanics of TMJ was clearly defined by the finite element method. Method: 1 cases of orthodontic orthodontics were selected to complete and have been diagnosed clearly. A healthy adult male with simple osseous mandibular retraction is scanned by 16 layers of X ray computed tomography to obtain the DICOM format data of CT plain and three-dimensional reconstruction of the maxillofacial region, combined with Mimics, Geomagic Studio, Unigraphics NX, and the removal of the mandible and its upper teeth, bilateral joint fossa, and the temporal bone. The model was removed from the median sagittal and one side (left) was studied. The 0.2mm thick periodontal membrane was established on the surface of the clinical root of the half side model. The 0.3,0.5mm thick cartilage was established on the surface of the condyle head and the joint fossa, and the condyle in the model was divided into the anterior condyle according to the gap between the condyle head and the joint fossa. The 4 regions of the oblique, transverse, posterior, condylar neck were divided into 5 regions: the anterior, the central, the medial, and the outside. The model was marked with the masseter, the temporalis, the intramuscular and extragarial muscles and the direction of the muscle strength. The model was recorded as the preoperation model. The position of the mandibular anterior migration is set as a clinical common 4,8,10mm, which keeps the muscle attachment area unchanged. The direction of the original muscle force varies with the position of the attachment area of the muscles and becomes the ultimate direction of the muscle force, and regenerates a new one according to the gap between the condyle head and the joint fossa. The corresponding models are the model 1,2,3. in workbench for the contact type, the type of interface and the coefficient of friction in the model of 1,2,3 in the post operation model, the type of interface and the coefficient of friction to set the tetrahedral mesh, set the fixed constraints, and set the masticatory muscle strength according to the maximum masticatory muscle state after the material properties of the component and the size of the masticatory muscle strength. Results: 1. the results were as follows: 1. the TMJ, the FE model of the mandible and the masticatory muscle system of the mandible and the masticatory muscle system were successfully established before and after the operation and the mandibular migration, and the FE model of the mandible and the masticatory muscle system had better geometric similarity with the real TMJ and the mandible. 2. the vonmises stress distribution and the maximum vonmises stress value of the vonmises stress distribution of TMJ under the maximum masticatory muscle force in the discontinuous region of the mandible were successfully obtained before and after the maxillary mandibular retrusion, and the maximum vonmises stress in the condyle was located in the neck of the condyle. The maximum vonmises stress is maximum when the mandible moves forward 4mm. The maximum vonmises stress in the condyle head is located on the outer side of the front of the anterior oblique and the neck of the neck. When the mandible migrations 8mm, the maximum vonmises stress is maximum. The largest vonmises stress in the joint fossa before and after the 21.898mpa. orthognathic operation is located in the anterior region, when the mandible migrations before 10mm, The maximum Von Mises stress is maximum, and the stress of Von Mises in the posterior and lateral area of the joint fossa is obviously increased with the increase of the mandibular migration distance. In the process of the mandibular migration, the transverse ridge, the posterior oblique surface of the condyle, the maximum Von Mises stress in the central area of the joint fossa are small. The maximum Von of the medial section of the fossa fossa from 4mm to 8mm is migrating before the mandible. Mises stress increased greatly. The maximum Von Mises stress of the condyle neck decreased greatly when the mandibular forward migration ranged from 8mm to 10mm. The overall condyle Von Mises stress value was significantly greater than that of the articular fossa. Conclusion: the comprehensive use of Mimics, Geomagic Studio, Unigraphics NX, can establish a better geometric and mechanical resemblance to the bone. The FE model of the TMJ and the mandibular masticatory muscle system before and after maxillary orthognathic operation. The mandibular retrusion and the condyle neck of the mandibular condyle after orthognathic operation are the most concentrated parts of the TMJ stress. The anterior condylar surface of the condyle is the main functional surface of the condyle. In the long term, normal orthognathic surgery generally does not have a bad effect on the condyle and the temporomandibular fossa in the patients with skeletal mandibular retraction.
【学位授予单位】：西南医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R783.5
【参考文献】
相关期刊论文 前10条
1 闫磊;李善昌;庄亚严;张铁军;赵亮;;牵张力对大鼠髁突软骨细胞炎性因子及Hedgehog相关基因的研究[J];黑龙江医药科学;2016年01期
2 李叶;卢海平;谷志远;;应力下IGF-Ⅰ对颞下颌关节软骨的作用的研究进展[J];口腔医学;2015年06期
3 陈硕;刘筱菁;李自力;梁成;王晓霞;傅开元;伊彪;;下颌后缩畸形患者正颌外科术后髁突改建的三维影像评价[J];北京大学学报(医学版);2015年04期
4 黄林剑;李辉;谢千阳;张e，
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