摘要
目的 ：从生物力学角度分析髁突矢状骨折（sagittal fracture of the mandibular condyle,SFMC）坚固内固定术后的骨折愈合进程,为治疗SFMC提供依据。方法：以三维有限元法（three dimensional finite element analysis,3D-FEA）构建包含双侧髁突的下颌骨模型;设右侧髁突为骨折侧,模拟以4孔微型接骨板坚固内固定治疗法,设计术后0、4、8、12周为SFMC骨折愈合进程中的观测点,测算髁突应力分布变化,骨折断端位移、微接骨板受力、应力遮挡状况。结果：正常髁突最大等效应力位于髁颈部,分布于髁颈中1/3的片状区域。术后0周,患侧髁突最大等效应力为正常值的23倍,位于近骨折线中下1/3的髁突残端和近骨折线的螺钉固定处的接骨板上,呈点状分布;髁突及接骨板的其余部分几乎不受应力作用。术后4-12周,患侧髁突的最大等效应力趋于平稳,但仍为正常值的6倍左右。位于近髁突残端的镙钉固位处与髁颈中外1/3处的点状区域,其余部分几乎不受应力作用。髁突总位移及总转角在骨折愈合进程中增加0.57-0.75 mm及0.01-0.09°。髁突残端术后0周的最大等效应力是术后4-12周的5-6倍。髁突游离端在骨折愈合进程中的最大等效应力、总位移及总转角值均无显著变化。接骨板术后0周最大等效应力为术后4-12周的7-9倍。结论：SFMC愈合进程中,髁突承载应力及应变改变、接骨板的应力遮挡可能与髁突吸收、改建有关。内固定4周内,接骨板、髁突残端承载的最大等效应力、髁突总位移与总转角明显增大,可弹性颌间牵引,以减少髁突总位移及总转角;流质饮食可减少髁突等效应力,利于骨折愈合。内固定4周后,下颌骨及髁突已能承载正常负荷,可行康复训练,以尽早恢复TMJ的正常功能。
PURPOSE： To analyze the biomechanical healing process on rigid fixation of sagittal fracture of the mandibular condyle （SFMC）, and to provide guidelines for surgical treatment. METHODS： Three-dimensional finite element model （3D-FEAM） of mandible and condyle was established. The right condyle was simulated as SFMC with 0.1 mm space across the condyle lengthways. The 3D-FEAM of rigid fixation was established. The biomechanical factors such as stress distribution of condylar surface, displacement around fracture, stress on the plate and stress shielding were calculated during 0, 4, 8 and 12-week after rigid fixation. RESULTS： The maximum equivalent stress of normal condyle was located at the area of middle 1/3 of condylar neck. The maximum equivalent stress at 0-week after fixation was 23 times than that on normal condyle. They were located at the condylar stump and the plate near inferior punctual areas of fracture line. There were little stress on the other areas. The maximum equivalent stress at 4, 8 and 12-week was approximately 6 times than that on normal condyle. They were located at the areas same as the area at 0-week. There were little stress on the other areas at the condyle. The maximum total displacement and maximum total comer were increased 0.57-0.75 mm and 0.01-0.09° respectively during healing process. The maximum equivalent stress at 0-week on the condylar trump was 5-6 times compared with that at 4, 8, and 12-week. The maximum equivalent stress, maximum total displacement and maximum total corner on the fractured fragment were not changed significantly during healing process. The maximum equivalent stress at 0-week on the plate was 7-9 times compared with that at 4, 8, 12-week. CONCLUSIONS： The stress of the condyle and stress shielding of the plate may be the reasons of absorbing and rebuilding on the condyle in healing process of SFMC. The biomechanical parameters increase obviously at 4-week after fixation. Elastic intermaxillary traction is necessary to decrease total displace
出处
《上海口腔医学》
CAS
CSCD
2015年第2期164-169,共6页
Shanghai Journal of Stomatology
基金
宁夏回族自治区科技攻关计划项目(2011年度)~~
关键词
髁突矢状骨折
坚固内固定
三维有限元
生物力学
Sagittal fracture of the mandibular condyle （SFMC）
Rigid fixation
Three-dimensional finite element analysis
Biomechanics
