论文标题:下颌骨牵张成骨过程中颞下颌关节应力分布的分析研究
Three-dimensional Finite Element Stress Analysis of the Temporomandibular Joint during Mandibular Osteodistraction
论文作者 王燕
论文导师 丁寅,论文学位 硕士,论文专业 口腔临床医学
论文单位 中国人民解放军第四军医大学,点击次数 80,论文页数 62页File Size2868k
2003-04-01论文网 http://www.lw23.com/lunwen_309394822/ 下颌骨;牵张成骨;颞下颌关节;三维有限元;生物力学
mandible,distraction osteogenesis,Temporomandibular joint,three-dimensional finite element,biomechanics
牵张成骨(distraction osteogenesis，DO)是骨科发展得较为成熟的一项技术，但自90年代以来才逐步在口腔颌面外科领域应用，因而还有许多方面需要进一步探讨。颞下颌关节是人体最为复杂、精细的关节，双侧联动，构成一功能单位。有关颞下颌关节(Temporomandibular joint，TMJ)的研究主要集中在基础性研究(包括组织学变化和形态学改变)方面。随着有限元分析方法在口腔医学应力研究中的广泛应用，国内外学者对颞下颌关节及下颌骨的二维或三维应力分布进行了大量的研究。然而，应用三维有限元方法研究下颌骨牵张成骨过程中颞下颌关节的应力分布尚未见报道。本实验通过在计算机上建立包括下颌骨的颞下颌关节的三维有限元模型，初步分析了下颌骨牵张成骨过程中颞下颌关节的应力分布特征，为进一步研究奠定了一定的基础，并为临床应用提供一定的参考依据。 本研究内容包括：①运用ANSYS6.1有限元软件以及CT断层扫描与手工描记相结合的方法，建立包括下颌骨的颞下颌关节的三维有限元模型；②在所建的三维有限元模型上进行下颌骨DO的加载，所研究的四种DO类型为：下颌骨颏部正中DO、单侧下颌升支DO、双侧下颌升支DO、单侧下颌角DO。 研究结果表明： 1、建立了包括下颌骨的TMJ有限元模型。当在下颌骨进行牵张成骨时，颞下颌关节的应力分布表现为：随着加载力值的增加，关节内压应力、拉应 第四军医大学硕士学位论文力的大小也随着增加，但分布区域不变，即踝突后斜面、关节盘后带、踝突软骨后部持续受压；踝突前斜面、躲突中部、关节盘前、中带、踝突软骨前部持续受拉。 2、下颌骨颊部正中DO和双侧下颌升支DO时，两侧关节的压应力和拉应力均表现为外侧高于中、内侧。TMJ内最大压应力部位在踝突软骨的外后区，最大拉应力部位在骸突软骨的内前区。 3、单侧下颌升支 DO和单侧下颌角 DO时，加力侧TMJ的应力值明显高于对侧。同时加力侧TMJ应力表现为外侧高于中、内侧，而对侧表现为内侧高于中、外侧。加力侧TMJ内最大压应力部位在踝突软骨的外后区，最大拉应力部位在踝突软骨的外前区；加力对侧TMJ最大压应力部位在臊突软骨的后内区，最大拉应力部位在踝突软骨的内前区。
Distraction osteogenesis is a more mature technique in orthopedics. Since 1990s, it has gradually been developed in oral and maxillofacial surgery. So there are more discussions in unknown fields . Researches about temporomandibular joint focus on basic studies including histology and morphology. With the broad use of finite element method in stress analysis in stomatology , many native and foriegn scholars put up many studies on two-dimension or three-dimension stress distributions of the temporomandibular joint and mandible. But the research about stress distributions of the temporomandibular joint during mandibular osteodistraction is seldom. In this experiment, the character of stress distributions of the temporomandibular joint in the process of mandible DO was initially analysed by a finite element model (FEM) of TMJ model with mandible . Thus the speculation should be studied further and deeply in the future in order to make farther research and offer experimental basis in clinic. Method: ?ANSYS6.1 finite element software was adopted in the study to establish three-dimensional finite element model of mandible and TMJ. ?The four types of DO studied here were : mid-line osteodistraction, unilateral ramus osteodistraction, bilateral osteodistraction, unilateral angle of mandible osteodistraction.?3?The results indicated as the following:1 ? To establish a TMJ model including mandible by means of three-dimensional finite element methods. The stress values were increased by the loads increasing in the process of mandible DO. But the area distribution was invariable.The lateral stress was greater than it interior or mid.Compressive stress widely distributed in condyle posterior ram and articular disc posterior band. Tensile stress widely distributed in condyle anterior ram , anterior band and intermediate zone of articular disc.2? During mid-line osteodistraction or bilateral osteodistraction, the lateral stress was greater than it interior or mid on both sides of TMJ. The maximal compressive stress distributed in the posterior-lateral condylar cartilage.The maximal tensile stress distributed in the interior-anterior condylar cartilage.3 ?During unilateral ramus or angle of mandible osteodistraction, the stress values of the TMJ loading were much more higher than those of the TMJ on the other side. At the same time, the lateral stress was greater than that at interior or mid on the TMJ loading ,but the interior stress was greater than it lateral or mid of the TMJ on the other side. The maximal compressive stress distributed at the posterior-lateral condylar cartilage and the maximal tensile stress distributed at the anterior- lateral condylar cartilage of the TMJ loading. The maximal compressive stress distributed at the posterior- interior condylar cartilage and the maximal tensile stress distributed at the interior-anterior condylar cartilage of the TMJ on the other side.
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