PDF(Pubmed)
Abstract：
BACKGROUND: This study aimed to assess the impact of aligner activation and power arm length and material on canine and aligner displacement, von Mises stress in the power arm, and principal stress in the periodontal ligament (PDL) during canine tooth distalization using finite element analysis (FEA). The effects of aligner activation and power arm length were primary outcomes, while the effect of the power arm material was a secondary outcome.
METHODS: Aligner activation (0.1 mm or 0.2 mm) was applied without using a power arm in two models. The effects of aligner activation, power arm length (12, 13, or 14 mm) and power arm material (stainless steel [SS] or fiber-reinforced composite [FRC]) on canine distalization were investigated in 12 models by evaluating displacement and stress via ALTAIR OptiStruct analysis.
RESULTS: Greater canine displacement was observed in all models with 0.2 mm than 0.1 mm of aligner activation. When models with the same aligner activation were compared, reduced mesiodistal tipping, increased palatal tipping, and increased extrusion of the canine cusp were observed with increasing power arm length. Moreover, the von Mises stress increased as the power arm length increased. Increasing the aligner activation and power arm length increased the maximum principal stress in the PDL. Power arms of the same length in both materials showed the same results in terms of canine displacement, clear aligner displacement, and maximum principal stress in the PDL. However, under conditions of equal length and aligner activation, the von Mises stress of the SS power arm was higher than that of the FRC power arm.
CONCLUSIONS: Using a power arm in canine distalization reduced mesiodistal tipping but increased palatal tipping and extrusion of the canine cusp. Aligner activation and additional force increased tooth movement and principal stress in the canine PDL. FRC power arms exhibited less von Mises stress than SS power arms.
METHODS: Aligner activation (0.1 mm or 0.2 mm) was applied without using a power arm in two models. The effects of aligner activation, power arm length (12, 13, or 14 mm) and power arm material (stainless steel [SS] or fiber-reinforced composite [FRC]) on canine distalization were investigated in 12 models by evaluating displacement and stress via ALTAIR OptiStruct analysis.
RESULTS: Greater canine displacement was observed in all models with 0.2 mm than 0.1 mm of aligner activation. When models with the same aligner activation were compared, reduced mesiodistal tipping, increased palatal tipping, and increased extrusion of the canine cusp were observed with increasing power arm length. Moreover, the von Mises stress increased as the power arm length increased. Increasing the aligner activation and power arm length increased the maximum principal stress in the PDL. Power arms of the same length in both materials showed the same results in terms of canine displacement, clear aligner displacement, and maximum principal stress in the PDL. However, under conditions of equal length and aligner activation, the von Mises stress of the SS power arm was higher than that of the FRC power arm.
CONCLUSIONS: Using a power arm in canine distalization reduced mesiodistal tipping but increased palatal tipping and extrusion of the canine cusp. Aligner activation and additional force increased tooth movement and principal stress in the canine PDL. FRC power arms exhibited less von Mises stress than SS power arms.
摘要：
背景：这项研究旨在评估矫正器激活和动力臂长度以及材料对犬科动物和矫正器位移的影响，冯·米塞斯在动力臂上的压力，和使用有限元分析（FEA）的犬牙扩张过程中牙周膜（PDL）的主应力。矫正器激活和功率臂长度的影响是主要结果，而动力臂材料的影响是次要结果。
方法：在两个模型中不使用动力臂的情况下应用对准器激活（0.1mm或0.2mm）。矫正器激活的影响，通过ALTAIROptiStruct分析评估位移和应力，在12个模型中研究了犬远距的动力臂长度（12、13或14mm）和动力臂材料（不锈钢[SS]或纤维增强复合材料[FRC]）。
结果：在矫正器激活0.2mm比0.1mm的所有模型中观察到更大的犬位移。当具有相同对准器激活的模型进行比较时，减少近端倾翻，增加腭倾翻,随着动力臂长度的增加，观察到犬齿尖的挤压增加。此外，vonMises应力随着动力臂长度的增加而增加。增加矫正器激活和动力臂长度增加了PDL中的最大主应力。两种材料中相同长度的动力臂在犬类位移方面显示出相同的结果，明确对准器位移，和PDL中的最大主应力。然而,在相同长度和对准器激活的条件下，SS动力臂的vonMises应力高于FRC动力臂。
结论：在犬扩张中使用动力臂减少了犬中远端倾翻，但增加了犬尖的腭倾翻和挤压。对准器激活和额外的力增加了犬齿PDL中的牙齿移动和主应力。FRC动力臂比SS动力臂表现出更小的冯·米塞斯应力。
方法：在两个模型中不使用动力臂的情况下应用对准器激活（0.1mm或0.2mm）。矫正器激活的影响，通过ALTAIROptiStruct分析评估位移和应力，在12个模型中研究了犬远距的动力臂长度（12、13或14mm）和动力臂材料（不锈钢[SS]或纤维增强复合材料[FRC]）。
结果：在矫正器激活0.2mm比0.1mm的所有模型中观察到更大的犬位移。当具有相同对准器激活的模型进行比较时，减少近端倾翻，增加腭倾翻,随着动力臂长度的增加，观察到犬齿尖的挤压增加。此外，vonMises应力随着动力臂长度的增加而增加。增加矫正器激活和动力臂长度增加了PDL中的最大主应力。两种材料中相同长度的动力臂在犬类位移方面显示出相同的结果，明确对准器位移，和PDL中的最大主应力。然而,在相同长度和对准器激活的条件下，SS动力臂的vonMises应力高于FRC动力臂。
结论：在犬扩张中使用动力臂减少了犬中远端倾翻，但增加了犬尖的腭倾翻和挤压。对准器激活和额外的力增加了犬齿PDL中的牙齿移动和主应力。FRC动力臂比SS动力臂表现出更小的冯·米塞斯应力。
