Measurement of the Kinematics of Mandible Using Single Plane Fluoroscopy and Cone Beam CT

• Main Authors: Chun-Yu Huang, 黃鈞郁
• Other Authors: 陳韻之
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/98939124056221901258

碩士 === 國立臺灣大學 === 臨床牙醫學研究所 === 96 === Introduction: Recording all 6 degree-of-freedom (DOF) is an essential requirement to study the complete mandible rigid body kinematics. However, most of the instrumentations available need trans-oral components, which might interfere the physiological jaw movements, to hold the signal senders. A new 2-D/3-D registration technique has been successfully applied to study the kinematics of knee joints and spines, etc. by using single-plane fluoroscopy and CT without any additional markers. The aim of this study was to evaluate the possibility of applying such technique to study the kinematics of the complicated constructed mandible. Materials and Methods: A porcine head with complete dentition with radiopaque crystal beads attached to the teeth in the embrasure regions was scanned with conebeam CT to yield the 3D virtual model. Single-plane fluoroscopy was used to record the simulated mandible opening movements driven by a simple hydropumping device. Based on the pre-requisite of pointed x-ray source of the conebeam CT/fluoroscopy unit, the projected 2D mandible and marker beads shown on the single-plane fluoroscopy can be derived from the 3D model through a function of projection. Therefore, the spatial information of jaw position that produced best-matched projection with the fluoroscopic image was used to estimate the mandible rigid body motion. Results: The tissue contrast shown on the fluoroscopy is too blurred to identify the detail of the mandible projection. However, the crystal marker beads can be easily identified and used as reference to bridge the CT and fluoroscopic images. By using the marker beads, the 2D/3D registration technique can yield a high precision movement recording with error limited within 0.12 degrees and 0.66 mm for rotation and translation, respectively. Conclusion: This in vitro study has demonstrated that mandible rigid body kinematics can be precisely measured without trans-oral components by using single-plane fluoroscopy.