Abstract Maxillary protraction and expansion is recommended to treat midfacial deficiency in patients with cleft lip and palate (CLP), where amount and direction of forces can change displacement and stress. This study assessed the initial displacement and stresses using Facemask and Maxgym forces with and without RME at +20∘, 0∘, and -20∘ angulation using a finite element (FE) model of unilateral cleft lip and palate (UCCLP). The Initial displacement and stress were more for protraction with expansion as compared to only protraction. Asymmetric displacement was observed with more on cleft than on noncleft side and more on dental than skeletal structures. Palatal plane rotated less upward, increased arch width and decreased arch length was observed with protraction with expansion.

中文翻译：

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单侧唇腭裂模型颅面结构在变力和变力牵引治疗过程中初始位移和应力的三维有限元分析

摘要 上颌前伸和扩张被推荐用于治疗唇腭裂（CLP）患者的面中部缺陷，其中受力的大小和方向会改变位移和应力。本研究使用单侧唇腭裂 (UCCLP) 的有限元 (FE) 模型，在 +20∘、0∘ 和 -20∘ 角度下使用面罩和 Maxgym 力在 +20∘、0∘ 和 -20∘ 角度评估初始位移和应力。与仅延长相比，初始位移和应力更多地用于延长延长。观察到不对称移位，裂隙多于非裂隙侧，牙齿多于骨骼结构。腭平面向上旋转较少，随着扩张的延长，观察到牙弓宽度增加和牙弓长度减少。