基于虚拟（牙合）架技术的TMD患者髁突运动的三维可视化研究

Temporo-mandibular joint disorder is common disease in oral clinical practice. But there is extended conflict in its etiology, prognosis as well as treatment. There is few means for three-dimensional visualization of mandibular tracing, especially for condyle movement. In former research, we had developed new three-dimensional scanning system based on structured light projection, which could carry out continued survey in real time. Meanwhile, CT scanning data of healthy individual had been three-dimensional rebuilt and correlative reference frames had been set up. A pilot study of the mandibular movement had been worked out as well as condyle. But there is necessity of embedded research combining with mandibular trcing data, and the characteristic condyle movement of TMD patients should be exploited. Therefore, we will make registration and fusion of three-dimensional data derived from several kinds of photographic examination, catch the mandibular tracing through three-dimensional scanning based on structured light projection and build up virtual articulator system for volunteers. The codyle movement centers will be calculated by theory of spatial analytic geometry. Reference frames will be build up in three-dimensional software, which are used for calculating parameters of condyle movements. Then the virtual articulator system will be used to make three-dimensional visualization and parameters computing of codyle movements of TMD patients with abnormal mandibular tracing. The data derived from condyle movements of TMD patients and healthy volunteers and the data of TMD patients pre and after occlusion treatment will be compared and statistical analyzed. The relationship between occlusion treatment and condyle movement of TMD patients will be studied. New methods of clinical diagnosis and treatment plan of TMD will be summarized.

颞下颌关节紊乱病（TMD）是口腔临床上的常见病，但目前病因、诊断和治疗还存在争议。对于下颌运动，尤其髁突运动还缺乏三维可视化的描记手段。前期研究中，我们开发出基于结构光投影三维测量系统,并且利用正常人CT扫描数据初步尝试三维重建和建立相关坐标系，初步研究了下颌骨及髁突的功能运动，但是还需要结合下颌运动轨迹描记的数据进行深入研究，并探索TMD患者髁突运动的规律。为此，我们通过对多源性影像学重建的三维数据进行配准融合以及利用结构光投影测量下颌运动轨迹建立受试者的虚拟（牙合）架系统，并利用空间解析几何原理计算髁突运动中心，在三维软件上建立坐标系，定量描述髁突的运动参数。在此基础上，对下颌运动异常的TMD患者进行髁突运动的三维可视化研究和测量，比较TMD患者与正常志愿者以及TMD患者自身咬合治疗前后的髁突运动差异，研究咬合治疗对TMD患者髁突运动的影响机制，为TMD的临床诊断和治疗设计提供新思路。

颞下颌关节紊乱病是口腔临床常见疾病，通常对于颞下颌关节检查的方法包括X线片、CT扫描、MRI检查等，但对于髁突运动还缺乏三维可视化的描记手段。虚拟牙合架是运用计算机图形技术、虚拟现实技术、先进制造技术等创建出的用于取代传统机械式牙合架，模拟患者个性化的下颌运动轨迹和咬合状态的口腔医学新技术。由于虚拟牙合架与颞下颌关节、牙列、咬合关系密切，本项目拟建立虚拟牙合架系统研究下颌运动、咬合关系以及髁突运动情况，为建立一种新的临床诊疗方法进行初步研究。.项目实施过程中以5名颞下颌关节功能正常的医学生为研究对象，研究了如何利用螺旋CT数据、模型三维扫描数据等多源化三维数据建立个性化虚拟牙合架系统，利用双目立体视觉追踪多靶标球的测量原理描述下颌运动轨迹的方法。通过数字化技术实现了观察髁状突在不同下颌运动状态的位置、姿态以及与关节窝的间隙，取得了初步的研究结果。除此以外，研究中提出了利用逆向工程软件中三角面片干涉检测实验检测上下颌牙列的咬合接触状态和利用“运动对颌数据”来设计修复体，实现临床应用的模式。本研究获得的实验结果以数字模型的形式进行储存，研究中存在下颌运动轨迹描记精度的问题，需要进一步的实验验证。.研究中提出为受试者制作咬合导板，使下颌在正中位咬合抬高2-3mm的状态下进行螺旋CT扫描，能够更好地分离患者上、下颌骨的三维数据，使髁状突和关节窝形态更加准确，是一种良好的三维数据处理方法。另外，研究中提出利用面部特定部位固定球形标记物的方法代替扫描咬合导板对患者上下颌进行相对位置描记的方法，虽然在下颌轨迹描记上有一定的误差，但是为虚拟牙合架的研制提出了一种新方法，可以不使用大型的框架设备或在受试者牙齿上粘结导板而获取高精度的下颌运动轨迹数据，也更加有临床应用前景。