唇腭裂新生儿颅基底形态结构特征的研究

目的　在唇腭裂新生儿三维重建体上研究颅基底形态结构特征。方法　采用计算机辅助三维重建技术 ,对 6例正常胎儿及 5例唇腭裂新生儿标本颅基底形态结构作立体定量的分析比较。结果　唇腭裂患儿颅底角无明显异常 ,而后颅底长增加 ,前颅底倾斜度减少 ,双侧完全性唇腭裂还表现出前颅底长、宽均有异常。结论　研究结果表明颅基底异常是唇腭裂畸形的综合表现之一。     

唇腭裂新生儿鼻上颌复合体形态结构特征的研究

目的　对唇腭裂患儿鼻上颌复合体的形态特征进行三维立体的测量分析。方法　采用计算机辅助三维重建技术 ,对 6例正常胎儿及 5例唇腭裂新生儿标本的鼻上颌复合体的形态结构进行了测量。结果　唇腭裂患儿上颌骨及邻近结构宽度异常 ;牙槽弓组织不足 ,且主要表现在前段牙槽 ;前段牙槽上倾 ,提示前段组织错位或垂直向生长不足 ,而后段牙槽高度接近正常。结论　唇腭裂患儿出生时即存在上颌骨不同方向的错位和发育异常 ,因此 ,对畸形的矫正 ,可以提供接近正常的解剖结构基础 ,有助于上颌骨正常生长发育 ,并为外科修复提供良好的手术条件 ,有助于颜面形态和口腔功能的更好恢复。     

唇腭裂术后对裂侧上颌恒侧切牙发育的影响

唇腭裂是一种最常见的口腔颌面部先天发育畸形,1987年国内统计资料新生儿疾病的发病率为1.82‰.先天发育缺陷及手术修复常导致患儿颅面骨骼形态发育异常;而对于牙列,裂隙局部的干扰常出现在侧切牙区,表现为裂隙邻近牙齿的畸形、扭转,牙齿的先天缺失及多生牙的出现.研究认为乳牙列更常常发现多生牙,而恒牙列多表现为裂侧侧切牙缺失.本文旨在研究唇腭裂畸形对患者裂侧恒侧切牙发育的影响.     

含骨缝唇腭裂颅上颌有限元模型的建立及有效性验证

目的:利用CT原始数据建立一个包含骨缝的唇腭裂颅上颌复合体有限元模型,并对模型的有效性进行验证,为唇腭裂颅上颌相关的生物力学研究提供一个可靠的建模依据.方法:选择1例替牙期单侧唇腭裂(unilateral cleft lip and palate,UCLP)患者进行颅面部螺旋CT扫描,利用所得CT原始数据、三维重建软件Mimics和逆向工程软件Geomagic Studio建立一个颅上颌复合体的三维几何模型,再导入Solidworks三维CAD软件中,进行颅面部12条骨缝的切割和建模,最后在自编软件中进行网格划分和赋予材料属性.模拟临床条件,在所建模型上施加上颌前牵引力,分析颅上颌各骨性结构的位移及骨缝应力分布情况,并与文献资料进行对比,验证模型的有效性.结果:建立了一个包含骨缝并具有生物力学特征的颅上颌复合体有限元模型,模型由206 753个单元和260 662个节点组成.模型的几何相似性和有效性好,可被用于相关的生物力学研究.结论:应用CT薄层扫描数据结合相关工程软件,是一种有效的建立含骨缝唇腭裂颅上颌有限元模型的方法.     

高精度光学导航辅助颅颌面骨畸形整复的技术方法建立与应用

目的：通过自主建立用于颅颌面手术的高精度计算机导航软硬件系统,模拟和精确设计手术方案,实现术中实时可视化手术导航。方法：（1）创建颅颌面整复手术规划及导航软件（TBNAVIS—CMFS）。（2）建立基于Polaris光学定位仪的导航工作站。（3）临床上对50例复杂颅颌面畸形患者实施导航辅助矫治与修复重建手术。结果：TBNAVIS—CMFS以清晰的界面和简洁的操作．实现了高精度数字化手术规划;导航辅助的颅颌面骨畸形整复术取得了精确可靠的手术效果,减少了手术创伤。结论：计算机导航技术结合颅颌面整复外科,将有利于从疾病诊断、术前模拟、术中导航等方面推动颅颌面外科趋于精确和微创。     

计算机辅助测量唇腭裂继发颌骨畸形患者手术前后口腔及气道容积的变化

目的 采用计算机辅助三维重建技术,测量并比较单侧完全性唇腭裂继发颌骨畸形患者双颌手术前后固有口腔(oral cavity proper)及上气道容积的变化,评估数字外科引导下正颌手术对于患者气道及语音的影响.方法 获取2015年7月至2019年12月收治的5例单侧完全性唇腭裂继发颌骨畸形患者接受双颌手术前后口腔CBCT...     

成年唇腭裂患者术后颅面硬组织三维形态研究

目的:对单侧完全性唇腭裂(UCLP)术后成年患者颅面骨进行三维测量分析,总结其颅面骨三维结构特点。方法:选取18～25周岁UCLP术后成年患者(UCLP组)及因其他疾病就诊的正常唇、腭和正常患者(对照组)各30例,进行锥形束CT扫描,分别测量颅面部骨组织的某些线距和角度,对比2组间测量结果的差别。结果:反映颅基底形态的测量项目UCLP组与对照组相比较,均未发现显著差异;UCLP组的上颌长度、腭部长度与宽度均小于对照组,下颌骨下部宽度及下颌骨联合深度均低于对照组,下颌角角度则大于对照组;UCLP组颌间矢状向与垂直向关系与对照组无明显差异,颏部后缩较为明显。结论:唇腭裂因素及手术因素未对患者颅基底结构产生影响,上颌矢状向发育受限,腭部横向发育受限,上下颌骨间矢状向与垂直向关系基本维持正常。     

替牙期正常儿童颅面骨三维定量测量的研究

目的研究下颌骨处于正常牙尖交错位时,替牙期正常儿童颅面骨三维空间的相对位置关系。方法选择33名正常范围的替牙期志愿者,在正常牙尖交错位状态下行螺旋CT扫描,三维影像重建。在AW4.2工作站上对重建的颅面骨影像进行三维测量,将测量的线距、角度、比值等数据进行统计学分析。结果在统计学分析中,可以由计算机自动计算任意例数组的平均数、标准差、标准误、中位数、变异系数和任意两组数据的比值。颅面骨CT三维测量较为客观和精确地反映出在正常牙尖交错位时替牙期颅面骨三维空间的相对位置关系。结论螺旋CT三维测量精确性高,提供信息多,测量值的标准差远小于其均值。本研究提供替牙期正常儿童颅面骨三维测量的正常数据,为颅面骨畸形的儿童患者提供早期诊断、早期治疗的量化分析依据。     

计算机辅助设计在单侧完全性唇腭裂婴儿术前矫治中的应用

目的:评价计算机辅助设计在单侧完全性唇腭裂患儿术前矫治中的应用价值。方法:对10例单侧完全性唇腭裂新生儿取模,通过三维激光扫描仪对模型进行扫描并实现三维重建,三维诊断设计软件模拟整个错位上颌骨各骨段的矫正过程,并输出用于矫治器加工的数字模型。快速激光成型技术恢复矫治过程的模型并制作一系列矫治器,临床应用于单侧完全性唇腭裂患儿的术前矫正治疗。结果:经过3～4个月的术前矫正,错位牙槽骨排列成较为规则的弧形;唇部裂隙宽度减小,鼻翼塌陷畸形得到改善,鼻小柱偏斜得到纠正。结论:计算机辅助设计的单侧完全性唇腭裂患儿术前矫治能实现精确、量化的矫治目标,同时减少复诊次数,是一种高效、简洁的术前矫治方法。     

唇腭裂患者颅面不对称性研究

唇腭裂患者颅面不对称性研究周恒综述李巍然，林久祥，傅民魁审校先天性唇腭裂是由于胚胎时，尤其是第６－１１周面部突起融合发育障碍所致。这种缺陷可能对同一时间发育的其他颅面骨骼成分，尤其是邻近缺陷的区域产生影响［１０］。头颅侧位片的研究表明患者存在明显的上...     

Three-dimensional analysis of dental casts based on a newly defined palatal reference plane

The purpose of this study was to establish a new method for orthodontic diagnosis that integrates the three-dimensional (3-D) shape of a dental cast and the craniofacial morphology using a newly defined palatal reference plane. We also measured the accuracy of this new palatal reference plane as a reference for measurement and its spatial relationship to the framework of the craniofacial skeleton using lateral and frontal cephalometric radiography and maxillary dental casts, which were transferred using an anatomical face-bow. Eighteen female subjects were included in this study. The new reference plane in dental cast analysis corresponded to the A-PNS plane in the lateral view and to the J-J' plane in the frontal view, which have been shown to be sufficiently accurate as a reference for measurement. These results indicate that the application of this palatal reference plane, as a reference structure, should provide accurate and abundant 3-D data concerning malocclusion.     

颅面外科三维诊断分析和手术设计系统的建立

目的　探讨正常颅面结构内在美学规律、研究复杂颅面畸形的解剖结构特征及其整复手术设计方法。方法　建立了颅颌面外科三维诊断分析和手术设计计算机系统 (3DCMFCADS) ,并将系统应用于正常颅面分析和颅面畸形整复手术设计。结果　所建系统整机运行稳定 ,测量分析误差微小 ,精密度最大变异系数仅 1.92 % ,手术模拟设计和构建的移植体或植入体三维模型形态逼真、参数准确。所建系统和方法的优特点表现在 :1可同时显示硬、软组织结构并对其进行三维测量分析和手术模拟设计。 2可显示颅面立体结构 ;可定性和定量地诊断分析颅面畸形 ;可进行手术模拟并设计移植或植入修复体三维模型。 3可利用国内较普及的 CT扫描机和微型计算机设备开展工作 ,系统操作方法易于为外科医生掌握使用 ,具有临床实用性。 4定量诊断和手术设计的准确性、精密度高 ,且具有客观性。结论　 3DCMFCAD系统和方法的建立为颅面畸形形成机制研究、诊断分析、手术设计和疗效评价提供了新的科学方法和理论依据。     

网格投影面部形态三维测量法初步研究

本文介绍了一种面部形态三维重构和测量新方法。用投影仪向墙上垂直投照网格,人端座于墙前,面部处于网格范围内,在另一位置拍摄面部照片并用微机处理,即可重构出面部三维形态并可给出大量测量参数。该方法设备简单、结果直观,测量可靠、利于推广,能成为口腔医学中形态学研究的有用工具。     

基于二维DR的颅面硬组织与软组织拟合的研究

目的:以数字化X线摄影片(digital radiograph,DR)图像和激光扫描为数据源,三维重建颅面硬组织和软组织,并进行硬软组织的有效拟合,以期为治疗方案确定、手术方法选择和提高医患交流的水平提供平台.方法:在志愿者面部贴定铅点,拍摄头颅正侧位DR片.利用基于二维DR数据的颅面硬组织三维重建系统进行硬组织形变建模.获得颅面部硬组织模型.利用激光扫描数据进行面部软组织三维重建,获得面部软组织三维模型.然后通过铅点坐标的匹配,将颅面硬组织与面部软组织进行拟合.结果:分别重建了能反映真实颅面部组织结构的硬组织三维模型和面部软组织三维模型,并实现了颅面部硬组织与软组织的有效拟合.结论:本研究实现了颅颌面三维结构的有效重建和拟合,为进一步进行正颌手术模拟和容貌预测奠定了基础.拟合结果真实可靠,能够用于临床.     

包含骨缝的颅面复合体三维有限元模型的建立

目的：探讨利用螺旋CT原始数据建立包含骨缝的颅面复合体三维有限元模型的数字化方法,建立一个具有生物力学特性的包含骨缝的动态颅面复合体三维有限元模型。方法：采用多排螺旋CT对恒牙早期骨性安氏Ⅲ类患者行常规头部平扫及三维数字影像重建,利用原始DICOM数据建立颅面复合体三维几何模型,在MSC．Metant前处理软件工具中划分网格。结果：建立了完整的颅面复合体三维体几何模型和包含骨缝的完整颅面复合体三维有限元模型,由630,379个单元和148,143个节点组成。探索出一条适用于活体的颅面骨合体三维有限元数字化建模方法。结论：应用螺旋CT薄层扫描、三维重建软件Mimics和非线性有限元分析工具MSC．Marc相结合的方法,建立包含骨缝的颅面复合体三维有限元模型是一种快速有效的方法。     

CT-based size and shape determination of the craniofacial skeleton: a new scoring system to assess bony deformities in hemifacial microsomia

The purpose of this study was to design a better craniofacial classification system for bony deformities in patients with hemifacial microsomia than the existing ones. It was meant to incorporate the deformity of the craniofacial skeleton other than that of the mandible. The "Mandibular Deformity Scoring" System (MDS), the "Cranial Deformity Scoring" System (CDS), the the "Craniofacial Deformity Scoring" System (CFDS) are three newly developed classification systems, which are based on three-dimensional computed tomography (3-D CT) reconstructions. The size and shape of the craniofacial structures of 34 children, 25 with hemifacial microsomia and 9 with minimal dysplasia or trauma, were determined from CT scans, using 3-D image segmentation and rendering. Contiguous 1.5-mm CT scans were made using a Philips Tomoscan 350 and were processed using a Cemax 1500X 3-D workstation. The precision of the 3-D imaging was assessed by repeated determinations carried out by two observers (intra- and interreliability). Accuracy of the bone determination technique was assessed by comparing the interpretations of the craniofacial skeleton by 3-D CT reconstructions of laser-stereolithographic 3-D models. Correlations of the Pruzansky/Kaban classification system and the newly developed classification systems were demonstrated by the use of the Pearson product moment correlation coefficients. The new CFDS (= CDS + MDS) provides an adequate basis for assessment of bony structures using three-dimensional imaging and demonstrates a high correlation with the known Pruzansky/Kaban classification system. This new scoring system can handle the wide variety of individual variation of the deformity seen in patients with hemifacial microsomia better than the existing scoring systems.     

Three-dimensional reconstruction: a new method for the evaluation of apical microleakage

The purpose of this study was the evaluation of a new method for studying apical microleakage by using a three-dimensional (3-D) reconstruction method. Fourteen human single-rooted mandibular teeth were used for this work. The canals were prepared with hand instruments by using the step-back technique. To supply a focus to the study of the method, the teeth were divided into two groups that were obturated using two different sealers. India ink was used for passive stain. Serial cross-sections 0.75 mm thick were taken from each specimen by using a special microtome. Each section was photographed under a stereoscopic microscope. Each photograph was digitized and processed to obtain a 3-D reconstruction of the external surface of the teeth, their corresponding prepared root canals, and their apical microleakage. Sample size and experimental methods were not designed to make valid groups; however, apical microleakage was observed in both groups ranging between 2.25 to 8.25 mm height. The 3-D reconstruction method has proved to be a useful tool in the study of apical microleakage.     

应用激光扫描法实现磨牙金属全冠三维重建的实验研究

目的：实施磨牙金属全冠的三维重建。取得全冠的数字模型，以便于用快速成型的方法制作磨牙金属全冠。方法：应用台湾区CNC镭射扫描系统，将金属全冠的蜡型进行扫描，在计算机中形成全冠的三维图像，应用逆向工程软件形成全冠的数字模型。结果：得到了全冠的三维重建数字模型，其件为STL格式。结论：重建方法可行，所得数字模型可用于全冠的计算机辅助制作。     

颞下颌关节磁共振三维重建的实验与临床应用研究

目的：建立颞下颌关节磁共振三维重建方法：探讨三维重建影像与大体解剖结构的一致性。以证实该方法的准确性：分析该方法在颞下颌关节紊乱病临床诊断中的意义。方法：对小型猪颞下颌关节进行磁共振扫描，进行三维重建，并对小型猪进行解剖，观察其大体形态，将两者进行比较，对1名无症状志愿者及1名颞下颌关节紊乱病患者进行增强磁共振扫描，并进行三维重建。结果：小型猪磁共振三维重建影像与大体解剖形态基本一致，2名受检者的三维影像均可清晰再现颞下颌关节各结构的形态及相对位置关系。结论：磁共振三维重建方法能准确反映颞下颌关节解剖形态，并具有广泛的临床应用前景。     

Modeling of structure, quality, and function in the orthodontic patient

The advantages of three-dimensional (3-D) imaging technology and solid modeling make it possible to visualize the morphological information. However, lacking in this 'digital patient' is the motion and mechanical properties observed in the living patient. Functional diagnostic techniques such as electromyography and motion analysis could complement the morphological characteristics to be applied in orthodontics. In this review, new computer-assisted analyzing methods are introduced which include visualization of: 1) the 3-D structure and bone density distribution; 2) masticatory-generated forces by using automated finite element modeling (FEM); and 3) the 3-D jaw movement and its motion analysis. In each study, the data from X-ray computed tomography scanning, electromyograms, biting pressure, and digital jaw movement analysis (six axes) are used for calculation. By using these applications, growing changes in bone mineral density distribution of the mandibular cortical bone have been clarified, automated finite element modeling has indicated stress distribution in the craniofacial skeleton, and patient-specific 3-D images of the mandible have been depicted as a motion picture. These studies were completed in 124 living subjects (75 females, 49 males) between 8 and 33 years of age. From these results, malfunctions during mastication were evaluated clearly with the individual patient craniofacial structures and its characteristics. These computer-based visualization techniques can be used to derive much clinically useful information, and to improve the combined evaluation of both static characteristics and dynamic function.