Development of dental operation and diagnosis simulation system using volume rendering

通过使用虚拟现实触觉设备PHANToM操作由3D形状测量系统VIVID 900或X射线-CT测量的牙列和面部的3D表面和体积数据，开发了随后的牙科手术和诊断支持系统。（1）种植手术支撑：可模拟骨钻孔和种植体植入。可以完成支架的CAD/CAM制造，为植入物插入时的骨钻孔提供指导。（2）模拟截骨术：利用PHANToM对颅骨进行三维CT图像的切割和重排。通过CG图像可以定量地模拟和观察骨块之间的空间和干扰量的移动和旋转的骨块之间的重新排列。骨模型可以使用快速原型系统构建。（3）去除口腔区CT图像中由金属覆盖物引起的伪影：对牙体模型进行CT测量，并与颅骨图像进行配准，用口腔区周围受损图像代替模型图像。（4）牙列模型的CT三维测量：采用医用CT测量牙列模型，与激光测量相比，测量效果更好。

By operating 3D surface and volume data of the dentition and the face measured by 3D shape measuring system VIVID 900 or X ray-CT by using virtual reality haptic devise PHANToM, the following dental operation and the diagnosis support system were developed.(1)The implant operation support: The simulation of bone drilling and implant insertion could be accomplished. The CAD/CAM fabrication of stent that is a guide for bone drilling for implant insertion considering the condition of bone could be accomplished.(2)The simulation of osteotomy : The 3D CT image of cranial bone was operated by cutting and rearranging using PHANToM. The space and the amount of interference between bone pieces by the movement and the rotation of the bone pieces for rearrangement could be simulated quantitatively and observed by CG image. The bone model could be constructed using a Rapid Prototyping system.(3)The removal of the artifact of the CT image in the oral area originated by metallic restorations: The dental cast was also measured by CT and the image was registered to that of cranial bone, and the cast image were replaced with damaged image around oral area.(4)The 3D measurement of the dentition model by CT: The dental cast model was measured by using medical CT with excellent effectiveness comparing with laser measurement.