运动捕捉技术对下颌开闭运动的数字化采集及分析

摘要

Objective To explore the six degrees of freedom of jaw opening and closing movement with motion capture and analysis system to establish a quantitative method for studying mandibular movement and a digital basis for virtual reality study of mandibular movement. Methods In a male adult with normal dentition without temporomandibular joint disorders, 3 fluorescent markers were pasted in the upper dentition and 4 in the lower dentition. Six cameras of the motion capture system were arranged in a semi-circular fashion. The subject sat in front of the camera at an 80-cm distance with the Frankfort plane kept parallel to the horizontal plane. The degree-of-freedom (3 linear displacement and 3 angular displacement) of jaw opening and closing movement was obtained by collecting the marker motion. Results Six degrees of freedom of jaw opening and closing were obtained using the motion capture system. The maximum linear displacements of X, Y and Z axes were 5.888 089 cm, 0.782 269 cm, and 0.138 931 cm, and the minimum linear displacements were -3.649 83 cm, -35.961 2 cm, -5.818 63 cm, respectively. The maximum angular displacements of X, Y and Z axes were 0.760 088°, 2.803 753°, and 0.786 493°, with the minimum angular displacements of-2.526 18°,-0.625 94°, and-25.429 8°, respectively. Variations of linear displacements during jaw opening and closing occurred mainly in the Y axis, and those of angular displacement occurred mai ily in the Z axis. Conclusion The six degree-of-freedom of mandibular movement can be accurately obtained with the motion capture system to allow quantitative examination of the mandibular movement.%目的 利用Motion capture运动捕捉及分析系统，获得下颌开闭口运动的6个自由度，探索下颌运动的数字化分析方法，同时也为下颌运动虚拟还原奠定了基础。方法 1例咬合关系正常的健康成年男性，上牙列粘贴荧光标志物各3个，下牙列粘贴荧光标志物各4个，6个摄像头呈半环形排列，接受测试者端坐位于摄像头前80 cm，眶耳平面平行于水平面，采集开闭口运动过程，获得运动的6个自由度。结果采用动态捕捉技术获得下颌开闭口运动的6个自由度，X轴线、Y轴线、Z轴线最大线位移分别为:5.888089 cm、0.782269 cm、0.138931 cm，X轴线、Y轴线、Z轴线最小线位移分别为:-3.64983cm、-35.9612 cm、-5.81863 cm;X轴、Y轴、Z轴最大角位移分别为:0.760088。、2.803753°、0.786493°，X轴、Y轴、Z轴最小角位移分别为:-2.52618°、-0.62594°、-25.4298°。下颌开闭口运动线位移主要发生在Y轴，角位移主要发生在Z轴。结论Motionanalysis运动捕捉及分析系统，可以敏感地获得下颌运动的6个自由度，量化了下颌运动的过程，进一步形成下颌运动的量化评价指标。