用电子散斑干涉技术作磁力扩弓效应的实验研究

An experimental study of magnetic maxillary expansion by electronic speckle pattern interferometry

目的:对利用钕铁硼永磁体制成的磁力扩弓装置扩大上颌后上颌复合体产生的瞬时初始生物力学效应进行研究。方法:选取一具年龄在12岁新鲜的人尸体头颅骨为实验对象,保持完整的上腭黏膜,保留颅颌骨缝间纤维及牙周膜。磁力扩弓分别在1、5、15、30、60min进行观察。使用电子散斑干涉仪测量扩弓后上颌骨表面的离面位移和变形,并与微机图象处理相结合。结果:整个上颌骨及其周围邻接骨,相应的牙齿显现出清晰的干涉条纹,随着时间的变化,在上颌复合体的不同部位所产生条纹的密度和形状均不相同。结论:磁力扩大上颌的初始应力效应主要传导在上颌复合体的深部结构上。

Objective:To investigate the biomechanical effect of magn et ic expansion by a new electronic speckle pattern interferometry. Methods :One fresh human skull of 12 years old with intact suture tissues and pe riodontal membrane was adopted. Magnetic expansion was loaded on the maxilla for 1,5,15,30 and 60 min respectively by magnetic force (NdFeB).Relative informa tion on the maxillary complex was acquired by electronic speckle pattern interfe rometry(ESPI). The deforming fringes was processed by the microcomputer image s ystem and the corresponding out-of plane displacement of the maxillary complex was analyzed. Results:Fringes of the maxillary complex were obs erved on monitor screen when magnetic force was loaded. From 1 min to 30 min-lo ading the fringe density was increasing, but decreased 1 h after loading. There was no fringe in the suture of the skull. Greate deformity was found on the lowe r part of maxilla. Conclusion:Magnetic force of expansion is con centrated in the deep structure of the maxillary complex.