Katada H
Shikwa Gakuho. 1989 Aug;89(8):1339-83.
For the purpose of analyzing deformations and movements in the maxilla loaded by orthopedic force to the maxillary first molar, a three dimensional finite element model of the maxilla was constructed. For modelling of the maxilla, the right side of an adult Indian skull was used. Constructed model was composed of 1,108 solid elements and 1,195 nodes. Materials of this model was composed of compact bone, cancellous bone, teeth and sutures. Constraint condition was fixed adjacent bone side surrounded by sutures. Load was directed from upward to downward 30 degree, changing every 30 degree reference to occlusal plane. Volume of load were weighed at 1 kg for each directions. Results 1. At upward load, stress was transmitted through the lateral wall of the maxillary sinus. The posterior portion of the maxilla was displaced more upward than anterior. Each process of the maxilla and the maxillary sinus was deformed, however, there was no stress on the orbitary surface. 2. At upward 60 degree load, the maxilla was compressed simply to the direction of load. At the upward 30 degree load, it was compressed backward-downward and rotated clockwise together with bending. 3. At backward load, the maxilla was moved backward and rotated clockwise. At downward 30 degree load, the maxilla was moved backward-downward and rotated clockwise. Both loads bended anterior portion of the maxilla and compressed posterior portion. The center of rotation or bending fell on the line joining the frontal process and the zygomatic process. 4. Of all five directions, backward load showed the maximum value of displacement and upward showed the minimum. Concerning with the absolute value of principal stress, backward load showed the maximum and upward 60 degree load showed the minimum. 5. Concerning with the principal stress value of sutures, compressive stress were distributed equally at upward load. However, as the load went to downward direction, it caused stress concentration. Especially, compressive stress in the pterygopalatine suture and transverse palatine suture, extensive stress in the midpalatal suture were especially great.
为了分析对上颌第一磨牙施加矫形力时上颌骨的变形和运动情况，构建了上颌骨的三维有限元模型。在上颌骨建模时，使用了一名成年印度人颅骨的右侧。构建的模型由1108个实体单元和1195个节点组成。该模型的材料包括密质骨、松质骨、牙齿和缝线。约束条件是固定由缝线包围的相邻骨侧。载荷方向相对于咬合平面向上30度，每隔30度改变一次。每个方向的载荷量均为1千克。结果1. 向上加载时，应力通过上颌窦侧壁传递。上颌骨后部比前部向上移位更多。上颌骨的各个突起和上颌窦均发生变形，但眶面无应力。2. 向上60度加载时，上颌骨仅沿加载方向压缩。向上30度加载时，它向后下方压缩并顺时针旋转同时伴有弯曲。3. 向后加载时，上颌骨向后移动并顺时针旋转。向下30度加载时，上颌骨向后下方移动并顺时针旋转。两种载荷均使上颌骨前部弯曲并压缩后部。旋转或弯曲中心位于额突和颧突的连线上。4. 在所有五个方向中，向后加载时位移最大值，向上加载时位移最小值。关于主应力绝对值，向后加载时最大，向上60度加载时最小。5. 关于缝线的主应力值，向上加载时压应力均匀分布。然而，随着载荷方向向下，会引起应力集中。特别是，翼腭缝和横腭缝处的压应力、腭中缝处的广泛应力尤其大。
