一种基于配准融合的三维牙齿模型重建方法

目的 完整且精确的数字化牙齿模型对于正畸治疗具有重要意义,然而通过三维光学扫描只能获得较高精度的牙冠而无法获得牙根信息,并且锥形束CT(CBCT)重建后的模型精度不够,无法用于正畸矫治器制作。为正畸过程分析及正畸方案设计研究一种精确的牙冠及牙根模型。方法 采用光学扫描仪扫描无锡市人民医院5例临床病例的牙齿数据,采用开源软件包ITK分离出牙颌中独立的牙冠模型,将病例的CBCT数据进行三维面重建,重建出完整的牙齿数据,把牙冠模型与面重建后的牙齿模型采用最近点迭代算法进行空间位置配准,并将配准后的牙根与光学扫描的牙冠进行数据融合,获取到最终的模型。结果 光学扫描模型上颌模型平均三角面数量约182 257个,顶点数量约89 264个;下颌模型平均三角面数量约179 195个,顶点数量约81 206个。CBCT图像每例均为328层图像。该方法可以有效地将CBCT图像与光学扫描图像结合生成完整牙齿;5例病例重建融合后的平均误差为0.204 mm,可满足隐形正畸要求。结论 试验方法获得的完整牙齿可用于整个正畸过程的辅助诊断,可以避免进行多次的CBCT扫描带来的X射线辐射。     

基于逆向工程和快速成型技术的髋骨三维实体模型个性化重建

背景：髋骨解剖结构复杂,传统的X射线片及CT扫描等二维影像检查易受到影像重叠、软组织等的干扰,在髋骨的诊断中具有一定的局限性。通过基于逆向工程技术的数字化建模能全面、直观、精确地显示髋骨立体形态和各部位解剖结构的空间关系,在骨骼研究中有着广阔的应用前景。 目的：利用计算机辅助技术重建个性化的髋骨三维实体模型。 方法：使用手持式三维激光扫描仪对人体髋骨表面进行扫描,得到大量点云数据,综合使用工程软件Geomagic和计算机辅助软件CimatronE对点云进行处理并实现三维模型重建,使用快速成型机完成髋骨的3D打印,得到几何形状一致的髋骨实体模型。 结果与结论：通过基于逆向工程和快速成型技术的数字化建模方法,可得到具有良好几何相似性及生物力学特性的髋骨三维实体模型,可为人工仿生髋骨的数字化制造、虚拟装配、应力分析及模拟手术等提供精确的模型基础。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

数字三维影像测量模型在复杂长骨骨折修复中的应用：随机对照、6个月随访、临床试验方案

BACKGROUND: During internal fixation for complex long bone fractures, it is difficult to position the internal fixator completely to the contours of the bone surface, often resulting in unstable fixation and affecting the quality of the repair. Digital three-dimensional (3D) models were therefore established based on computed tomography (CT) scans that closely reflected the site and degree of fractures, thereby guiding precise positioning of the internal fixator. From a safety point of view, the digital 3D-derived model was created to ensure that the internal fixator could achieve better repairs of complex long bone fractures.     

三维打印组织工程牙计算机辅助设计建模技术的应用

背景：国内外关于如何成功构建组织工程牙支架材料内部空间构型的文献报道较少。 目的：建立适用于组织工程牙需求的支架材料CAD空间构型及支架结构实体微观模型STL格式文件。 方法：采用MICRO CT对离体大鼠第二磨牙进行连续扫描,将MICRO CT获得的DICOM格式文件导入MIMICS软件,将生成的三维模型导入GEOMAGIC12软件,提取外层轮廓,利用偏移功能模拟得到大鼠磨牙外层轮廓数据。利用CATIA V5R17软件构建支架材料空间内部多孔微观模型单体,在空间合适坐标上阵列得到组织工程牙内部支架整体模型,通过变更单体构型还可快速建立多种整体支架构型。装配大鼠磨牙外层轮廓数据与内部空间支架得到三维打印组织工程牙CAD 模型STL文件。 结果与结论：成功建立了牙体组织支架微观结构CAD模型,该CAD STL模型可直接用于三维打印系统快速成型组织工程牙支架。说明基于结合计算机逆向与正向工程建模技术,可快速建立多种符合组织工程牙要求的支架材料空间构型。中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程      

3D打印导板辅助腰椎皮质骨螺钉置入的可行性

BACKGROUND: Cortical bone trajectory is a new lumbar posterior internal fixation technology, whose trajectory is different from traditional internal fixation technology. Cortical bone trajectory led to high failure rate lacking of experience for insertion. However, the three-dimensional template improves its safety and accuracy.     

计算机辅助设计导板修复上颌后种植体头部和角度偏离不影响 种植体的植入精度

BACKGROUND: Maxillary posterior tooth defects can be repaired using the dental implant. However, implantation accuracy is not ensured by traditional plaster models used as implant template, which leads to the incidence of complications, and affects the repair effects. OBJECTIVE: To study application effects of surgical guide plates designed using the computer aided design (CAD)/computer aided manufacturing (CAM) technology for the repair of maxillary posterior tooth defects. METHODS: Implant treatment was performed in 30 patients with maxillary posterior tooth defects. Surgical guide plate was made using the CAD/CAM technology after CT scan of the jaw bone. The repair was conducted with guide plate assistant. The deviation between the virtual and actual implant position was measured after implantation. The clinical repair effects and periodontal tissues were observed during the 12-month follow-up. RESULTS AND CONCLUSION: Thirty-six CAD/CAM surgical guide plates in 30 patients were stabilized after implantation. Thirty-six implants were emplaced precisely with the assist of the surgical guide plates. There was no any problem during the process of implantation. The deviation of the head between the virtual and actual implant position was very small, which did not affect the accuracy of implant placement. Before and 6 and 12 months after the repair, gingival crevicular fluid, tumor necrosis factor-α, and sulcus bleeding index were not obviously changed in the patients. Our results suggest that the implant head deviation and angle deviation appear during the repair process of maxillary posterior tooth defects using CAD/CAM surgical guide for dental implants; however, the implantation accuracy is not affected. The repair effect is ideal and periodontal tissue is in good status after implantation. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

基于3D打印技术选择性椎弓根螺钉治疗青少年特发性脊柱侧凸

BACKGROUND: Three-dimensional (3D) printing has been popular for preoperative planning, and has been extensively used in bone tumor resection and pelvic fractures achieving satisfactory treatment outcomes. However, seldom used in adolescent idiopathic scoliosis.     

基于数字化设计和3D打印胫骨近端骨折内固定的关键技术

BACKGROUND: Preliminary experiments have performed three-dimensional (3D) reconstruction of proximal tibial fractures, digital steel plate design, the establishment of the proximal tibia plate standard parts library and the operation simulation of 3D printing.     

三维术前计划较二维模板测量更精确拟定人工膝关节置换假体型号

BACKGROUND: It is the key point to choose the right size of the prosthesis, and grasp the direction and thickness for osteotomy during total knee arthroplasty. In order to achieve the goal, accurate preoperative planning is very important.     

基于3D打印技术股骨头减压联合骨髓间充质干细胞移植专用移植器的研制及应用

BACKGROUND: Autologous tissue-engineered bone marrow mesenchymal stem cells (BMSCs) transplantation is one of the most common methods of treating early osteonecrosis of femoral head, but now there is still no any special-purpose grafter available in the market. Such surgical transplantation is a laborious, time-consuming and tedious process, which goes against its clinical promotion.     

CT三维重建评价椎弓根螺钉位置分级的可信度分析

背景：近年来已逐步采用CT来评价椎弓根螺钉位置,但是对应用CT三维重建评价椎弓根螺钉位置的可信度报道较少。 目的：探讨应用CT三维重建评价椎弓根螺钉位置分级的可信度。 方法：收集了27例椎弓根螺钉置入患者,置入后1周内行CT扫描,由2位专业骨科主治医师随机观察CT二维和三维影像资料,根据Rao分级方法对螺钉位置进行分级,利用一致性检验来评价观察者间信度和观察者自身信度。 结果与结论：27例患者共置入椎弓根螺钉116枚。利用二维CT图像资料,对螺钉位置分级的判定观察者间信度和观察者自身信度均为高度一致,Kappa系数分别为0.656和0.631。利用三维重建CT图像资料,对螺钉位置分级的判定观察者间信度和观察者自身信度均为最强,Kappa系数分别为0.833和0.863。说明CT三维重建在评价椎弓根螺钉位置的可信度较高,具有一定的临床应用价值。 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

基于图像数据建立器官三维模型

背景：近年来,三维重建与生物力学的研究日益增多,利用计算机由建模软件基于图像数据建立器官三维模型,再经有限元分析软件进行力学分析。作者检索文献发现国内外学者对人体器官三维重建的原理不够清晰,过程描述比较简单,有的与事实不尽相符,不能很好地为相关研究起到指导作用。目的：阐述器官三维模型重建的原理、过程、结果以及进一步应用,为后续研究提供科学依据。方法：应用计算机在中国知网数据库中检索关于人体器官三维重建有代表性的文献,分析阐述器官三维模型重建的原理、过程、结果以及进一步应用。结果与结论：结合建立出的骨三维模型详细阐述了三维重建的原理、过程、以及应用,为后续生物力学的研究奠定了理论基础。随着组织工程技术的不断发展,学者们己开始多角度、多方面来研究骨损伤的发病机制,以便更好地预防和治疗。相关研究现仍处于基础阶段,尚需深入研究。中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程