平行于功能平面水平向后牵引猴上颌骨矫形作用的三维有限元研究

3D fi nite-element study on displacement of craniofacial complex with retractive forces parallel to the occlusion plane on the maxilla of rhesus monkeys

目的采用螺旋CT断层扫描原始DICOM数据,建立猴颅面复合体三维有限元模型,并对其在后牵引矫形力载荷条件下的生物力学特性进行初步探讨。方法选用混合牙列期雄性恒河猴1只,行螺旋CT扫描,建立猴颅面复合体三维有限元模型。利用ANSYS 12.1软件分析不同大小后牵引矫形力作用下,上颌骨各标志点在三维方向上的位移变化。结果随着力值的加大,各标志点的位移变大,位移与力值大小呈线性关系。其中,在x轴方向,各点的位移均较小;在y轴方向,各点的位移呈现较大的变化,方向沿y轴向后,而且随力值加大,位移增加明显;在z轴方向,上颌前部的上齿槽座点和前鼻棘点位移向下,上颌骨后部的后鼻棘点位移向上。结论水平向后牵引对上颌骨有明显的后移作用且上颌产生顺时针方向的旋转,但对上颌宽度产生的影响较小。

Objective To construct a 3D finite-element model of the craniofacial complex with the original DICOM data of CT and to investigate the preliminary biomechanical characteristics with different directions and magnitudes of retractive forces to the maxilla of rhesus monkeys. Methods A male rhesus monkey with mixed dentition was used. Spiral CT was performed to establish a 3D finite-element model of the craniofacial complex. The ANSYS 12.1 software was used to ana- lyze craniofacial complex displacement. Results Each landmark showed larger displacement with increasing force value. The displacement values and force size exhibited a linear relationship. In the x-axis direction, all displacements were small. In the y-axis direction, all displacements showed significantly higher changes with increasing force value displacement. In the z-axis direction, the A-point and ANS point moved downward, but PNS moved upward. Conclusion Loading retractive force resultes in an apparent backward and clockwise rotation on the maxilla with no obvious effects on the width of the upper jaw.