单侧完全性唇腭裂患者上颌前牵引的对称性有限元研究

A finite element study of the symmetry of maxillary protraction in patients with unilateral complete cleft lip and palate

目的:探讨单侧完全性唇腭裂患者上颌前牵引的对称性问题。方法:在已建立的植骨前单侧完全性唇腭裂上颌骨有限元模型上,应用Ansys软件模拟牙槽突裂植骨构建植骨后模型,在植骨前后模型上分组添加前牵引力,第一组:未植骨模型上添加对称性前牵引力;第二组:植骨模型上添加对称性前牵引力;第三组:未植骨模型上添加非对称性前牵引力;第四组:植骨模型上添加非对称性前牵引力。对矢状向位移量进行组内及组间比较。结果:前三组健侧位移均显著大于患侧(P<0.01),第四组健患侧位移差异无统计学意义(P>0.05),第一组健患侧位移差显著大于第二组(P<0.01)。结论:单侧完全性唇腭裂患者植骨前行上颌前牵引会出现明显前移不对称,植骨可以使不对称性降低,若同时选用不对称前牵引力则前移不对称现象可消失。

Objective:To study the symmetry of maxillary protraction in patients with unilateral complete cleft lip and palate.Methods:On the established finite element model of the maxilla before bone grafting,Ansys was used to simulate alveolar bone graft to form the model of maxilla after bone grafting.Symmetrical protraction force was applied to the model before bone grafting(group 1)and at the model after bone grafting(group 2),asymmetric protraction force was applied to the model before bone grafting(group 3)and at the model after bone grafting(group 4),respectively.Sagittal displacement was compared within and between groups.Results:Displacement of noncleft side in the first 3 groups was significantly larger than that of cleft side(P<0.01).There was no statistical difference between the noncleft side and the cleft side in group 4(P>0.05).Displacement difference between the noncleft side and the cleft side in group 1 was significantly larger than that of group 2(P<0.01).Conclusion:There will be obvious forward asymmetric movement in maxillary protraction before bone grafting for patients with unilateral complete cleft lip and palate.Bone grafting can reduce asymmetry.If asymmetric protraction is adopted at the same time,the forward asymmetry can disappear.