两侧非对称性下颌牙槽嵴形态对全口义齿稳定性影响的初步探讨

目的：初步探讨下颌两侧非对称性牙槽嵴形态对全口义齿稳定性的影响.方法：利用激光三维扫描仪取得下颌无牙颌标准模型牙槽嵴表面形态数据,通过计算机辅助工程（CAE）软件形成下颌全口义齿,标准形态牙槽嵴黏膜,以及4种左右形态非对称的牙槽嵴黏膜三维有限元模型：首先建立标准牙槽嵴（S）,其次按下颌牙槽骨不同部位吸收至S的1/4高度为条件,分别形成右侧磨牙区吸收（Rm）,右侧后牙区吸收（Rpm）,右侧牙槽骨吸收（Rapm）及左侧前牙区和右侧牙槽骨吸收（LaRapm）的黏膜模型.在S条件下义齿左右两侧咬合面的双尖牙区P,第一磨牙区M1及第二磨牙区M2等6个部位分别设定位于牙槽嵴顶及其颊侧的2个加载位置,共计12个加载点,单侧垂直加载9.8N的力,利用三维有限元分析各条件下义齿最大综合位移.结果：M1加载时各牙槽嵴条件下的义齿最大位移较P和M2加载时的小.各部位加载时LaRapm条件下义齿最大综合位移都较其他牙槽嵴条件下的大.左侧M2加载时的Rapm较Rm和Rpm的大,P加载及右侧M2加载时的Rm、Rpm、Rapm相近,且都大于S.结论：在单侧加载条件下,下颌两侧非对称性牙槽嵴前牙区高度影响全口义齿稳定性.

Influence of the bilateral asymmetric mandibular residual ridge morphology on the stability of complete denture

Objective：To investigate the influence of the asymmetry of mandibular alveolar ridge on complete denture stability.Methods：Three-dimensional laser scanner was used to obtain the standard model of mandibular edentulous alveolar surface morphology data through computer-aided engineering （CAE） software.Dimensional finite element model of the mandibular denture,the standard form of alveolar mucosa,as well as four kinds of morphological asymmetry alveolar ridge mucosa were set up.Firstly,the standards alveolar ridge model（S） was established.And then according to different parts of the mandibular alveolar bone absorbed to the 1/4 height of model S,we can set the following models：right molar absorption model （Rm）,right posterior area absorption model（Rpm）,right alveolar bone resorption model（Rapm） and the left anterior and right alveolar bone resorption mucosal model（LaRapm）.In S model,denture occlusal surface of the right and left premolar region P,the first and second molars MI and M2,a total of six parts of the district were set two loading positions as both the alveolar crest and buccal side,a total of 12 load points.Unilateral vertical load 9.8N force was set up.Three-dimensional finite element was used to analyze largest integrated denture displacement.Results：Compared with P and M2,denture maximum displacement in M1 loading conditions of the alveolar ridge was small.In various parts of the denture loading condition,LaRapm showed largest integrated denture displacement.Under left M2 loading condition,Rapm showed bigger denture displacement than Rm and Rpm.Under P and right M2 loading condition,Rm,Rpm,Rapm were similar and were larger than S.Conclusion：Under unilateral loading conditions,denture stability may be influenced by anterior alveolar height of mandibular residual ridge with bilateral asymmetric morphology.