Abstract：
OBJECTIVE: To three-dimensionally analyse the stress distribution and displacement pattern in the maxillofacial complex following intrusion and distalization of the maxillary arch using finite element analysis in skeletal class II malocclusion with prognathic maxilla and vertical maxillary excess using miniplates and mini-implants.
METHODS: Finite Element models of a skull, Y-shaped stainless steel miniplate, mini-implant and a posted arch were generated. Three force levels (1) 200 g (2) 300 g and (3) 500 g per side were applied to the assembly. The models were pre-processed and the analysis was performed using ANSYS version 18.1 software. Alterations in von mises stress, principal maximum stress, principal minimum stress and compressive stress were analysed around the sutures and surface landmarks.
RESULTS: With miniplates, there was a maximum stress concentration at the zygomatic buttress with even stress distribution at the fronto-maxillary, zygomatico-temporal, zygomatico-frontal and pterygomaxillary sutures along with anatomical landmarks such as frontal process of maxilla, ANS, Point A, prosthion and maxillary process of zygoma. First molars experienced greater distalization effects with buccal flaring when miniplates were used. With mini-implants, canine and premolars also exhibited greater distalization effects. In the root apices, lateral incisors showed increased lingual root movement with mini-implants.
CONCLUSIONS: Miniplates provide a greater distalizing effect while mini-implants produce increased intrusive effect. The distalizing effect is greater when 500 g of force is applied using miniplates with significantly even stress distribution and displacement pattern.
METHODS: Finite Element models of a skull, Y-shaped stainless steel miniplate, mini-implant and a posted arch were generated. Three force levels (1) 200 g (2) 300 g and (3) 500 g per side were applied to the assembly. The models were pre-processed and the analysis was performed using ANSYS version 18.1 software. Alterations in von mises stress, principal maximum stress, principal minimum stress and compressive stress were analysed around the sutures and surface landmarks.
RESULTS: With miniplates, there was a maximum stress concentration at the zygomatic buttress with even stress distribution at the fronto-maxillary, zygomatico-temporal, zygomatico-frontal and pterygomaxillary sutures along with anatomical landmarks such as frontal process of maxilla, ANS, Point A, prosthion and maxillary process of zygoma. First molars experienced greater distalization effects with buccal flaring when miniplates were used. With mini-implants, canine and premolars also exhibited greater distalization effects. In the root apices, lateral incisors showed increased lingual root movement with mini-implants.
CONCLUSIONS: Miniplates provide a greater distalizing effect while mini-implants produce increased intrusive effect. The distalizing effect is greater when 500 g of force is applied using miniplates with significantly even stress distribution and displacement pattern.
摘要：
目的：使用微型板和微型植入物对II类错牙合伴上颌骨和垂直上颌骨过剩进行有限元分析，以三维分析上颌骨侵入和扩张后颌面部复合体的应力分布和位移模式。
方法：头骨的有限元模型，Y形不锈钢迷你板，产生了微型植入物和后弓。向组件施加三个力水平(1)200g(2)300g和(3)每侧500g。对模型进行预处理，并使用ANSYS版本18.1软件进行分析。冯·米塞斯压力的变化，主最大应力,分析了缝合线和表面标志周围的主要最小应力和压缩应力。
结果：有了迷你板，zy骨支撑处的应力集中最大，上颌额部的应力分布均匀，合子-时间,颌骨-额叶和翼状颌骨缝合线以及解剖标志，例如上颌骨的额突，ANS,A点,a骨的假体和上颌突。使用微型板时，第一颗磨牙的颊扩张作用更大。有了微型植入物，犬和前磨牙也表现出更大的扩张作用。在根尖，侧切牙显示微型植入物的舌根运动增加。
结论：微型板提供更大的扩张效果，而微型植入物产生增加的侵入效果。当使用具有明显均匀的应力分布和位移模式的微型板施加500g力时，远端效应更大。
方法：头骨的有限元模型，Y形不锈钢迷你板，产生了微型植入物和后弓。向组件施加三个力水平(1)200g(2)300g和(3)每侧500g。对模型进行预处理，并使用ANSYS版本18.1软件进行分析。冯·米塞斯压力的变化，主最大应力,分析了缝合线和表面标志周围的主要最小应力和压缩应力。
结果：有了迷你板，zy骨支撑处的应力集中最大，上颌额部的应力分布均匀，合子-时间,颌骨-额叶和翼状颌骨缝合线以及解剖标志，例如上颌骨的额突，ANS,A点,a骨的假体和上颌突。使用微型板时，第一颗磨牙的颊扩张作用更大。有了微型植入物，犬和前磨牙也表现出更大的扩张作用。在根尖，侧切牙显示微型植入物的舌根运动增加。
结论：微型板提供更大的扩张效果，而微型植入物产生增加的侵入效果。当使用具有明显均匀的应力分布和位移模式的微型板施加500g力时，远端效应更大。
