摘要
目的分析4种不同类型的颌间牵引(颌间Ⅱ类长牵、颌间Ⅱ类短牵、颌间Ⅲ类长牵、颌间Ⅲ类短牵)情况下髁突和关节盘的应力分布和位移变化。方法采用螺旋CT扫描,Mimics、Ansys多种软件相结合的方法,建立包括颞下颌关节(TMJ)和上下颌骨及牙列的MBT直丝弓矫治器的左侧颅面骨三维有限元模型,模拟临床4种颌间牵引对该三维有限元模型进行分析。结果获得了4种颌间牵引情况下髁突和关节盘的应力分布和位移变化。工况一和二作用下髁突的应力分布规律相似,即髁突前斜面为压应力集中区,后斜面则主要为拉应力。工况三和四作用下髁突应力分布规律也很相似,髁突前斜面主要存在拉应力,后斜面则主要存在压应力。工况一和二作用下髁突的位移总体是向前向下移动,同时顺时针旋转;工况三和四作用下髁突的位移总体是向后向上移动,并逆时针旋转。结论颌间Ⅱ类长牵和短牵及Ⅲ类长牵和短牵应力分布规律相似,相同力值牵引时短牵的力量柔和。颌间Ⅱ类牵引总体位移向前下,髁突发生顺时针旋转;Ⅲ类牵引时总体位移向后上,髁突发生逆时针旋转。
Objective To analyze the influence of four types（classⅡ long elastic, class Ⅱ short elastic, class Ⅲ long elastic, class Ⅲ short elastic） of inter-arch elastics on the stress distribution and displacement of temporomandibular join（tTMJ）. Methods To reconstruct a three-dimensional element model of left craniofacial bones with TMJ, maxilla, mandible and dentition with MBT straight wire appliance by CT images, Mimics, Ansys software. The influence of four types elastic on the model was analyzed by simulating the clinical conditions. Results The stress distribution and displacement of TMJ under four types of elastics have been acquired. The stress distributed rule of condition 1 and 2 was similar, compression stress centred on the frontal surface of the condyle, while stretching stress centred on the posterior surface. The stress distributed rule of condition 3 and 4 was similar too, the frontal surface of the condyle was most stretching stress, while posterior surface was most compression stress. The displacement of the condyle of condition 1 and 2 was overall forward and downward with a clockwise rotation, the displacement of the condyle of condition 3 and 4 was overall backward and upward with a anticlockwise rotation. Conclusion Class Ⅱ long elastic and short elastic, class Ⅲ long elastic and short elastic, the stress distributed rule was similar, the strength under short elastics was gentle under the same strength value. Overall displacement was downward and forward under class Ⅱ elastics, the condyloid made a clockwise rotation. Overall displacement was upward and backward under class Ⅲ elastics, the condyloid made a counterclockwise rotation.
出处
《华西口腔医学杂志》
CAS
CSCD
北大核心
2010年第2期145-148,共4页
West China Journal of Stomatology
基金
吉林省科技厅基金资助项目(20040707-3)
关键词
三维有限元
颞下颌关节
颌间牵引
three-dimensional finite element
temporomandibular joint
inter-arch elastic
