放射定位标记模板技术在牙种植外科前三维影像分析中的应用

目的探讨放射定位标记模板技术在种植手术前三维影像分析中的作用和意义。方法应用空气压模技术制作标记有放射线阻射剂拟种植位点的放射模板，通过牙种植外科石膏模型，受试注塑模型、颅骨颌骨标本及临床种植病人颌骨的螺旋CT扫描，获取颌骨受植区域拟种植部位骨三维结构CT数据。结果确立的扫描平面即调整牙合平面与地面垂直（与X轴坐标线一致）能获得最佳侧断层图像；所有标记的CT模板均可在CT扫描后的轴位图像及颌重建侧断层和全景图像中清晰显现，且能达到准确的标定预种植位点。结论基于放射标记定位模板的评估方法可为种植外科前三维影像分析提供更为精确的手段，更有助于CAD／CAM种植外科定位导向模板的合理设计。

Evalution of application of radiographical template technique before dental implant surgery

Objective The aim of this study was to evaluate the 3-dimensional accuracy of image - guided dental implant placement based on radiographical template with radiopaque substance. Methods This procedure was experimen tally carried out on an acrylic resin model. Laboratory accuracy measurements were obtained. It was scanned by a multislice computerized tomography scanner （ Philip Brianliance 64 ） and registered with fiducial marker - based algorithms. The image materials were transfer to the computer system （CISPlan） to rebuild. Coordinates of target points were got by a 3D - digitizer probe and accuracy was accessed by comparing the difference between coordinates. Results Using a CT scan - based planning system, the surgeon is able to select the optimal locations for implant placement, taking into account specific anatomic characteristics of the patient and using the optimal bone densities. Conclusion The data obtained by this vitro study demonstrated that the accuracy of CT -based radiographieal template with radiopaque system may be sufficient for clinical treatment planning, particularly in terms of the transferability of preplanned trajectories. However, in vivo clinical trials need to be performed to evaluate the clinical accuracy and treatment quality of image - guided interventions.