【摘要】 目的 探讨夹板治疗颞下颌关节紊乱病（temporomandibular joint disorders,tmd)的生物力学机制。方法 采用三维有限元法模拟分析tmd患者夹板治疗前后下颌骨应力分布特征的变化。结果 夹板影响了tmd患者下颌骨的应力分布特征，使其下颌骨各部位最大、最小主应力明显降低，尤其是患侧髁突应力降低更为显著，使两侧髁突应力分布趋于一致，而下颌骨各部位应力对称性亦有所改善。结论 夹板通过改善颞下颌关节的应力分布状况（应力大小、性质和对称平衡性）减轻甚至消除对其的损伤，使失衡的关节内环境得到调整和恢复，此为夹板治疗tmd的最主要的生物力学机制之一。
effects of the occlusal splint on stress distribution of the mandible with temporomandibular joint disorders
hu kai, zhou jilin, liu hongchen, et al.
(department of stomatology, chinese pla general hospital, beijing 100853, china)
【abstract】 objective to investigate the biomechanical mechanism of occlusal splint therapy of temporomandibular joint disorders (tmd). methods the changes of stress distribution on the mandible with tmd before and after occlusal splint therapy were simulated and analyzed by three-dimensional finite element method. results occlusal splint influenced the character of stress distribution on the mandible. it might distinctly decrease maximum and minimum principal stresses on each region of the mandible with tmd, among which the stress on condylar surface of ill side was reduced more significantly, and the stress distribution of bilateral condyles was close to equality and balance. meanwhile, the stress symmetry on every position of the mandible was improved slightly. conclusions occlusal splint can alleviate even eliminate the injury to the temporomandibular joint, and make unbalance of joint inner environment adjusted and restored by improving the stress distribution . this is primarily thought to be one of the main biomechanical mechanism of occlusal splint treatment.
【key words】 occlusal splints； temporomandibular joint disorders； maxillamandible； stress，mechanical
夹板作为颞下颌关节紊乱病（tempor-omandibular joint disorders, tmd）保守治疗的有效方法之一，已在国内外得到广泛运用［1,2］。关于夹板治疗tmd的机理，大多数学者［3,4］认为其增加了颌间距离，使咀嚼肌张力减少；消除了干扰，使髁突恢复生理位置，以致肌肉、关节和颌位在新的、正常的生理环境下重新建立起平衡和协调。夹板如何影响tmj的受力状况，仅有少数学者进行了初步研究［5,6］，尚未见夹板治疗颞下颌关节（temporomandibular joint, tmj）疾病的应力分析。我们采用三维有限元分析技术，对髁突骨折导致tmd的患者模拟夹板治疗前后下颌骨应力分布的变化进行了定量分析，目的是从生物力学角度探讨夹板对tmd的作用机制。
材料和方法
1.三维有限元模型的建立与分析：选择右髁突颈部骨折伴错位愈合1年，骨折后曾行2周颌间结扎治疗，半年前出现关节弹响，现张口偏斜的成年男性tmd患者1例作为建模素材。该患者经6个月的夹板治疗、自述及临床检查发现关节弹响已消失，张口偏斜略有改善。其下颌骨螺旋ct扫描和三维影像重建、三维有限元模型建模方法、原则及加载方式见参考文献［7］。配戴夹板的tmd患者下颌骨三维有限元模型的形成方法：将患者原下颌骨三维有限元模型面约2mm厚的2层单元视为甲基丙烯酸甲酯树脂夹板，其弹性模量取值1.96×103 mpa，泊松比为0.30［8］。假设模型中的皮质骨、松质骨及夹板3组材料和组织为连续、均质、方向同性的线弹性材料。采用super sap大型结构分析处理软件计算，并对计算结果进行分析、归纳和整理。本新闻共3页,当前在第1页123
责任编辑：韩晓炜
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