牙弓长度对下颌牙根尖应力影响的光弹实验研究  

Photoelastic analysis of effects of apical stress distribution of the third molar in different occlusal patterns

作　　者：王景杰[1] 张日文[1] 王美青[1] 张俊华[1] 张渊[1] 

机构地区：[1]第四军医大学口腔医学院,陕西西安710032

出　　处：《牙体牙髓牙周病学杂志》2001年第6期382-385,共4页Chinese Journal of Conservative Dentistry

基　　金：国家自然科学基金资助项目 ( 39370 195 );高等学校骨干教师资助计划资助

摘　　要：目的 :探讨牙弓长度的改变对垂直加载时下颌各牙根尖应力的影响规律。方法 :采用透明环氧树脂复制以相同牙排列成含或不含第三磨牙的 3种咬合模型共 6副 :正常牙合、深覆牙合及单侧部分后牙反牙合。2 .0kg垂直加载后 ,投影式光弹仪上观测各牙根尖主应力的大小与方向。结果 :各模型下颌牙根轴倾角均无明显差别 ,根尖主应力大小也无显著差别。第三磨牙存在与否对正常牙合及深覆牙合的主应力方向无明显影响 (P >0 .0 5 ) ,而单侧部分后牙反牙合者 ,无第三磨牙时的反牙合对侧及反牙合侧非反牙合牙根尖主应力的远中向偏角比有第三磨牙时明显减小 (P <0 .0 1) ,而反牙合牙及其邻牙根尖主应力的近中向偏角也比有第三磨牙时小 (P <0 .0 5 )。第三磨牙的存在与否对大多数牙根尖的应力变化水平均无显著影响。结论 :正常咬合接触关系比牙弓形态更重要。AIM: To investigate the effect of dental arch length variation to the apical occlusal stress distribution in three different occlusal patterns. METHODS:Epoxy resin models of normal, deep overbite and partial posterior teeth cross-bite occlusion set up by identical plastic teeth with or without third molars were employed to determine the stress distribution in apical area under 2.0kg vertical load. The values and directions of main stress were measured. RESULTS: Existing of the third molars has no effects on the inclination angles of the root axes. The values of main apical stress, no matter in normal occlusion, deep overbite occlusion or in partial posterior teeth cross-bite occlusion, have no significant difference. The directions of the main apical stress in normal and deep overbite occlusion also showed no difference. As to the partial posterior teeth cross-bite occlusion, the angles of main apical stress disto-buccally were much lower when with the third molars. Besides above, existing of the third molars had no effects on the values of the main apical stress in most teeth. CONCLUSION: The occlusal relationship is much important than the shape of the dental arch during the transduction of the occlusal stress.

关 键 词：咬合 第三磨牙 应力 光弹法 

分 类 号：R780.2[医药卫生—口腔医学]