【摘要】 目的比较下颌角骨折后两种不同的内固定方法对其应力分布的影响。方法采用成人干燥无牙下颌骨,建立由咬肌、颞肌、翼内肌和翼外肌4组肌肉共同加载,由硅橡胶模拟颞下颌关节结构功能状态下的下颌骨机械力学模型。采用电阻应变片的测量方法,分析不同坚强内固定方式,即仅在下颌角上缘张力带固定一个小型接骨板和在下颌角下缘附加固定一个小型接骨板对下颌骨应力分布的影响。结果两种固定方法下健侧的应力分布与骨折前均无显著性差异(P>0.05),但是仅在下颌角上缘固定一个小型接骨板将使患侧下颌骨下缘呈张应力趋势,造成应力轨迹的中断。结论两种固定方法均可以恢复健侧的应力轨迹,但是要获得骨折区域充分的稳定性,固定两个小型接骨板是必要的。更多还原

【Abstract】 Objective To develop a functional biomechanical mandibular model, and to observe the stress distribution of angle-fractured mandible under different rigid internal fixation(RIF) methods. Methods A biomechanicalmodel of mandible was built which include the simulative temporal-mandibular joint(TMJ) and was under mechanical loads of masseter, temporalis, medial pterygoid and lateral pterygoid. The different stress pattern was measured by strain gauges. Under the standard mandibular angle fracture, bilateral molar biting and four pairs of muscles loading, the strains were compared to evaluate the stability of one-or two-miniplate fixation. Results The fixation of miniplate in the lateral oblique line can recover the main stress on the non-fracture side, but it was broken in the fracture side. The tension increased in the lower border of mandibular angle. Conclusion Through the biomechanical study based on the functional mandibular model, only one miniplate fixation in lateral oblique line for mandible angle fracture was insufficient buttressing of the segments, while the additional miniplate in the lower margin can recover the stress pattern and provide more stability.更多还原