计算机模拟正颌外科手术及疗效预测的研究

本文报告作者在个人计算机上开发的一个交互作用系统，用于模拟设计正颌外科手术及预测术后治疗效果。经临床应用取得了满意可靠的结果。     

应用计算机面像预测系统评价正颌手术效果

应用计算机面像预测系统对正颌手术效果评价。方法 ２４例牙颌面畸形患者在正颌手术前运用计算机面像预测系统作模拟手术，得到了模拟手术预测分析后的与预测面像，与术后实际的Ｘ线头颅定位片及彩色面像作比较。结果 预测像与实际软组织像除了下区域各方面都非常相似。     

正颌外科三维立体可视化模拟手术研究

目的：建立基于CT图像数据的计算机辅助三维立体手术模拟系统，为了术前进行精确设计手术方案及达到术后良好效果提供真实可靠依据。方法：应用医学可视化技术和Visual C^**编程语言开发出立体结构三维重建和手术模拟软件，建立以CT数据为信息源的计算机正颌外科立体可视化手术仿真模拟系统，可模拟各种正颌外科手术移动骨质过程，并且以动态动画形式演示，可从任意角度进行观察。结果：该系统建立了颅颌面畸形立体结构模型，以动态形式成功演示了正颌外科截骨移动手术仿真模拟，手术过程真实逼真，立体可视化效果好，应用普通播放软件即可在计算机屏幕上播放模拟正颌外科手术过程，并可预测手术后上下颌咬合状态及手术效果。结论：正颌外科三维立体可视化模拟手术系统的建立，为正颌外科截骨矫治牙颌面畸形术前手术方案制定提供实用有效的技术手段和全心的科学方法，改变仅凭主观经验诊断畸形和设计手术方案的传统模式，可在计算机屏幕前制定手术方案进行医患交流，共同协商，提高了正颌外科手术安全性、精确性和矫治效果。     

应用有限元法预测正颌术后三维软组织形变的初步探讨

目的:基于锥形束CT(CBCT)资料建立有限元模型,预测正颌术后三维软组织形变,探讨该方法的可行性与准确性。方法:选取下颌前突患者2例,于术前行颅颌面CBCT扫描,导入Mimics10.01软件,进行软、硬组织三维重建。采用Geomagic Studio11软件进行模型处理,并按实际情况进行手术模拟截骨,导入有限元分析软件AnsysWorkbench 11.0,建立线弹性有限元模型,加载位移后,经分析得出术后软组织三维模样,将其与术后6个月及以上的软组织三维重建图像对比,并进行定性及定量评价。结果:2例患者CBCT资料顺利进行有限元建模及预测,临床定性评价显示2例患者预测结果总体观察相似度高,但在口周及颊部相似度欠佳;Geomagic Qualify11定量检测显示,病例1误差小于2mm的区域为94.98%,病例2误差小于2mm的区域为90.71%。结论:采用线弹性有限元模型预测下颌前突正颌术后的软组织形态是可行的,可为临床提供较为可靠的参考。     

计算机辅助三维正颌外科硬组织手术模拟系统的初步研究

目的 :基于个人计算机实现三维正颌外科硬组织手术模拟 ,以期能够为术前诊断和制定定量化的手术方案提供参考。方法 :以Windows98为操作平台 ,采用医学三维可视化技术和VisualC6 .0编程语言开发三维正颌外科硬组织手术模拟系统。结果 :以CT为原始资料 ,成功地采用交互方式对正颌外科经典的几种手术截骨方式进行了模拟 ,系统可以反复进行手术模拟 ,直到结果满意为止。结论 :该系统的建立将为提高正颌外科临床诊断和治疗水平 ,促进医患的交流与合作发挥作用。     

计算机辅助正颌外科手术模拟预测系统的建立

目的:建立一套正颌外科手术模拟系统,为临床提供指导和数据参考,同时为教学提供形象化的教具。方法:在Windows环境下,采用VisualC 语言编制程序,借助彩色图像扫描仪和透射适配器以及数码相机等,将X线片等图象资料输入、储存于计算机,并随时将其调用和显示。在屏幕的X线片图象上进行手术模拟,将照片图象与X线片图象进行配准,获得患者的模拟预测容貌。结果:实现了一套精度高、速度快的正颌外科手术模拟系统。结论:本系统为一套精度高、速度快、效果良好的模拟系统。既为临床和教学提供方便,又为正颌外科领域的科研开辟了一条新路     

计算机化颅内三维测量及手术预测系统的研制及临床应用

简要报道我院开发建立的一个颅颌面畸形计算机化三维测量分析系统。方法系统内容主要有１。颜面部莫尔等高条纹的计算机测量与分析;２近景生物立体摄影技术在颅面畸形测量中的应用。３正颌外科手术的计算机模拟设计及面像预测;     

牙颌面畸形正颌手术的护理配合

目的　探讨如何加强牙颌面畸形正颌手术护理配合 ,确保手术成功的措施。方法　总结 5 0例牙颌面畸形患者的正颌手术。上下颌骨同时截骨 16例 ,单纯上颌骨或下颌骨截骨 34例 ,均行细致的术前准备和熟练的手术配合。结果　 5 0例正颌外科手术 ,手术时间最长 6h ,最短 2h ,均获得满意的手术效果。结论　牙颌面畸形正颌手术技术要求高且需特殊器械 ,手术前的准备工作及手术中熟练的配合是保证手术顺利进行的重要因素。     

正颌手术前后颜面软组织变形的三维有限元仿真研究近况

关于正颌手术前后病人面型变化的研究一直是正颌外科领域里的难题。传统的方法是通过模型—模板外科在手术前预测病人手术后的颜面软组织变化；近几年随着计算机技术的快速发展，应用计算机技术模拟面部软组织变形的研究越来越多，其中三维有限元的方法被应用的最多。这种方法可以精确地建立面部软硬组织的几何和物理模型，并在该模型上模拟手术过程及术后软组织变形。     

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牙颌面畸形正颌外科治疗需要根据畸形的情况、治疗的要求以及术前患者的生理、心理状态评估综合制定治疗方案.在术前必须对治疗方案、(牙合)关系的调整、骨切开的部位、骨段移动的方向和距离经过精确的设计.正颌外科的术前设计包括头影描迹设计、预测,计算机辅助设计以及模型外科等.本文结合笔者的临床经验和国内外文献对牙颌面畸形正颌外科治疗的术前设计进行述评,强调了牙颌面畸形正颌外科手术方案的设计原则,提出了计算机辅助外科在正颌外科领域具有显著的优势和广阔的应用前景.     

Virtual planning in orthognathic surgery

Numerous publications regarding virtual surgical planning protocols have been published, most reporting only one or two case reports to emphasize the hands-on planning. None have systematically reviewed the data published from clinical trials. This systematic review analyzes the precision and accuracy of three-dimensional (3D) virtual surgical planning of orthognathic procedures compared with the actual surgical outcome following orthognathic surgery reported in clinical trials. A systematic search of the current literature was conducted to identify clinical trials with a sample size of more than five patients, comparing the virtual surgical plan with the actual surgical outcome. Search terms revealed a total of 428 titles, out of which only seven articles were included, with a combined sample size of 149 patients. Data were presented in three different ways: intra-class correlation coefficient, 3D surface area with a difference <2 mm, and linear and angular differences in three dimensions. Success criteria were set at 2 mm mean difference in six articles; 125 of the 133 patients included in these articles were regarded as having had a successful outcome. Due to differences in the presentation of data, meta-analysis was not possible. Virtual planning appears to be an accurate and reproducible method for orthognathic treatment planning. A more uniform presentation of the data is necessary to allow the performance of a meta-analysis. Currently, the software system most often used for 3D virtual planning in clinical trials is SimPlant (Materialise). More independent clinical trials are needed to further validate the precision of virtual planning.     

Prototype of simulation of orthognathic surgery using a virtual reality haptic device

A maxillofacial simulator can support education and training. In the present study, cutting, separation, and quantitative rearrangement of bone during orthognathic surgery were simulated by means of a haptic device with virtual tactile perception. Computed tomographic (CT) images of two patients with severe jaw deformity, one women and one man, were input into the device. In the woman, Le Fort I osteotomy of the maxilla and sagittal splitting ramus osteotomy of the mandible were initially simulated. During surgery with the haptic device, separation and rearrangement of the maxilla and the ramus of the mandible were initially processed. However, there was discrepancy and overlapping of the ramus with the mandible. Intraoral vertical osteotomy of the right ramus was then performed, with satisfactory results and less discrepancy and interference. The simulation was referred to at surgery, and satisfactory surgical assistance was postoperatively confirmed on CT images. The male patient had severe jaw deformity due to unequal growth between the ramuses, resulting in anterior crossbite. Sagittal splitting ramus osteotomy with rotation of the mandible was successfully simulated. Because of its versatility and functions, the present device was found to be useful for simulating various procedures for orthognathic surgery and thereby three-dimensionally determine surgical movements.     

手术导航系统在口腔颌面外科中的应用

手术导航系统作为现代影像技术、立体定向技术、电子计算机技术和人工智能技术相结合的产物,近年来得到了迅速的发展和应用。本文就手术导航系统的概念和基本原理、发展情况、在口腔颌面外科中的应用等方面作一综述。     

基于虚拟现实技术的正颌手术模拟预测方法的建立

目的:探索建立基于虚拟现实技术的正颌手术模拟研究方法.方法:将颌面畸形患者CT断层图像利用Simplant软件行颅颌面骨组织三维重建,截骨,构建颅颌面骨树状结构模型.在虚拟环境碰撞模型上行上颌骨Le Fort Ⅰ型截骨、双侧下颌支矢状劈开及颏成形的手术模拟.结果:该系统形成的三维立体虚拟影像,可从任意视角观察,清晰逼真.运用系统工具进行骨组织的旋转、平移等手术模拟操作,实现了操作者与模型的交互作用,图像及触觉感知实时反馈,沉浸感强.应用该方法实现了正颌手术设计、虚拟操作及术后效果预测.结论:颅面三维虚拟正颌手术系统可以行正颌手术模拟及手术操作训练,在虚拟环境下实现图像反馈和力、触觉感知的手术模拟,具有较高的临床应用价值.     

Three-dimensional planning accuracy and follow-up protocol in orthognathic surgery: a validation study

The purpose of the study was to propose and validate a three-dimensional (3D) tool for the assessment of orthognathic surgery planning accuracy and postoperative follow-up. A total of 15 patients (four male, 11 female; mean age 29.6 years) with skeletal class II and III, who underwent bimaxillary surgery were recruited for the study. All patients had preoperative computed tomography (CT), and cone-beam computerized tomography (CBCT) scans 1–6 weeks and 6 months postoperatively. The data was exported to a customized stepwise module developed in Amira software resulting in the accuracy being presented as translational and rotational differences between the planning and the actual outcome. To evaluate the reliability of the proposed method, intra-class correlation coefficient (ICC) was applied at a 95% confidence interval on the translational and rotational output of two observers. The inter- and intra-observer reliability were found to be high (ICC range: 0.94–0.98) with mean variability of less than 0.4mm and 0.7° for translational and rotational movements for both planning accuracy and follow-up protocols. The study provides a reliable, quantitative and time-efficient method for evaluating the accuracy of virtual surgical planning and postoperative follow-up.     

计算机辅助颌骨畸形术前计划研究进展

颌骨畸形的治疗中,传统的方法需要X线头影测量与石膏模型外科技术的辅助。近年来,随着计算机辅助手术技术的兴起,计算机辅助设计和制造技术、快速原型技术越来越多地应用于颌骨畸形的术前规划和辅助治疗中。本文就计算机辅助颌骨畸形术前计划研究进展做一综述。     

Three-dimensional simulation and prediction of craniofacial surgery

The treatment of patients with complex facial deformities is one of the most challenging multidisciplinary tasks in plastic surgery. Due to advancements in medical technology and surgical techniques in the last 20 years correction of severe malformations has become possible and is performed by highly specialized teams frequently in a single operation. Recent developments in three-dimensional (3-D) imaging techniques have already greatly facilitated diagnosis of complex craniofacial deformities. Computer-based simulation methods for surgical procedures that are based on imaging data have the potential to improve surgical treatment by providing the ability to perform 'virtual surgery' preoperatively and thus reduce patient risk and morbidity intraoperatively. A method is presented for interactive computer-assisted craniofacial plastic surgery planning and visualization, especially simulation of soft tissue changes using an experimental Craniofacial Surgery Planner. The system computes non-linear soft-tissue deformation because of bone realignment. It is capable of simulating bone cutting and bone realignment with integrated interactive collision detection. Furthermore, soft-tissue deformation and cutting due to surgical instruments can be visualized. Simulation processes are based on an individual patient's preoperative 3-D computed tomography and on a 3-D, photo-realistic model of the patient's preoperative appearance obtained by a laser range scanner. Very fast and robust prediction of non-linear soft-tissue deformation is computed by optimizing a non-linear cost function.