3种截骨方式辅助上颌骨快速扩弓的应力分布  

Stress distribution of surgically assisted tooth-borne rapid maxillary expansion via three different types of osteotomies

作　　者：姜文辉[1] 王旭东[1] 王冬梅[2] 

机构地区：[1]上海交通大学医学院附属第九人民医院·口腔医学院口腔颌面外科,上海市口腔医学重点实验室,上海200011 [2]上海交通大学机械与动力工程学院,上海200030

出　　处：《上海口腔医学》2009年第6期609-614,共6页Shanghai Journal of Stomatology

基　　金：上海市科学技术委员会资助项目(08DZ2271100);上海市重点学科建设项目(S30206);上海市科技启明星计划(04QMX1424);上海交通大学"医工(理)交叉研究基金项目"(YG2007MS18)~~

摘　　要：目的:研究牙支持式外科辅助上颌骨快速扩弓(SARME)技术中应用3种不同截骨方式的颅面部骨骼应力分布情况。方法:建立牙支持式SARME系统的三维有限元模型,根据不同截骨方式,将模型分为3组,即Ⅰ型—单独的腭中缝截骨术,Ⅱ型—腭中缝+侧方皮质骨切开术,Ⅲ型—腭中缝截骨术+侧方皮质骨切开术+双侧翼颌连接截骨术。在模型上选取11个解剖结构,加载4种不同的扩弓量,比较分析颅面部各个部位骨骼的应力(von-Mises应力)分布情况。结果:SARME手术截骨程度越大,颅面部应力释放越多,最大应力值只出现在模型Ⅰ中;翼板处Ⅱ型手术应力比Ⅰ型明显增加;Ⅲ型截骨松解翼颌连接后,翼板的应力大大降低,同时面中部多数骨骼的应力也有所下降;Ⅲ型手术后面上部的解剖结构出现明显的应力回升。结论:手术辅助对于减小术后快速扩弓对颅面部产生的应力效果良好;翼板处应力集中,可能会增加颅底骨折的危险;离断翼颌连接后,面上份的应力集中可能是颅面部应力传导途径改变所致。PURPOSE：To investigate the stress distribution of craniofacial bones during surgically assisted tooth-borne rapid maxillary expansion（SARME） via three different osteotomies.METHODS：Three-dimensional finite element model of craniofacial bones with a tooth-borne appliance was generated.According to the different osteotomies,the models were categorized as three groups：Type I-isolated midpalatal osteotomy,Type II-Le Fort I and midpalatal osteotomies,Type III-Le Fort I and midpalatal osteotomies and bilateral pterygomaxillary disjunction.In all three models,with 4 different displacements,von-Mises stress was measured and analysed at 11 anatomical structures of the craniofacial bones.RESULTS：An obvious reduction of the stress was observed followed by the larger extent of the surgery.The maximum stress of the bones was only noticed in Type I model.Stress on lamina of the pterygoid acutely increased in the Type II model compared with the Type I model.In Type III model,after separation of the pterygomaxillary junctions,stress on lamina of the pterygoid decreased rapidly and meanwhile stressed on the majority of the midfacial bones also decreased.In Type III osteotomies,anatomical structures of the upper craniofacial bones suffered from an increase of the stress.CONCLUSIONS：Surgical procedures would be of great help to reduce the stress on the craniofacial region in the rapid maxillary expansion postoperatively.Fractures of the cranial base may occur at a greater chance because of stress focusing on lamina of the pterygoid.So,separation of the pterygomaxillary junctions during the operation is suggested.Increasing stress on the upper craniofacial bones can be observed after separation of the pterygomaxillary junctions due to changes of stress transduction pathways.

关 键 词：上颌骨 有限元分析 应力 牵引成骨 

分 类 号：R782.2.3[医药卫生—口腔医学]