【摘要】 目的 ：构建隐形矫治器序列远移下颌磨牙的有限元模型，探讨不同第二、第一磨牙起始位置进行远移时的牙列移动特点。方法：使用CBCT及口扫数据构建下颌骨、牙、牙周膜及隐形矫治器模型，依据第二及第一磨牙起始位置共分为8组工况。工况1～4—第二磨牙距第一磨牙分别为0、1、2、3 mm；工况5～8—第二磨牙远移至3.2 mm目标位，第一磨牙距第二前磨牙分别为0、1、2、3 mm。使用“两步法”模拟隐形矫治器加载并设定远移步距为0.2 mm，分析各工况牙列位移及矫治器形变特点。结果：各工况下，拟远移磨牙表现为牙冠向远中倾斜移动趋势，其余牙表现为反方向倾斜移动。随着拟远移磨牙的起始位置向远中改变，拟远移磨牙的远中移动量增加。工况4中，第二磨牙的远移量最大为0.11 mm。工况8中，第一磨牙远移量最大为0.10 mm。拟远移牙牙周膜等效应力值变化趋势表现为与位移类似的变化趋势。结论：隐形矫治器能够完成磨牙远中移动，但移动量无法达到预期值。随着拟远移磨牙起始位置向远中改变，远移量随之增加。更多还原

【Abstract】 PURPOSE: To construct a finite element model of the mandibular molars distalization with clear aligner, and to explore the characteristics of dentition movement and aligner deformation. METHODS: The models of mandible, teeth,periodontal membrane and clear aligne were constructed using CBCT and oral scan data, and were divided into 8 groups according to the starting position of the second and first molar teeth. Working condition 1-4: the distance between the second molar and the first molar was 0, 1, 2, 3 mm, respectively. Working condition 5-8: the second molar had moved far to the target position of 3.2 mm, and the distance between the first molar and the second premolar was 0, 1, 2 and 3 mm,respectively. "Two-step method" was used to simulate the loading of the clear aligner and set the distance of the step to0.2 mm, the characteristics of dental displacement and appliance shape change in each working condition were analyzed.RESULTS: Under each working condition, the molar with pseudo-remote displacement showed tilt movement of the crown to the far, and the other teeth showed reverse tilt movement. As the initial position of the pseudo-distant molar changed to the distal, the distal movement of the pseudo-distant molar increased. In working condition 4, the maximum displacement of the second molar was 0.11 mm, and in working condition 8, the maximum displacement of the first molar was 0.10 mm. The change trend of the Von Mises equivalent stress value of the periodontal membrane of the pretended distalization teeth was similar to that of the displacement. CONCLUSIONS: Clear aligner can complete distal movement of molar teeth, but the amount of movement cannot reach the expected value. As the initial position of the molars changed to the distal, the distance displacement will increase.更多还原