Development of a mechanical testing system for a mandibular distraction wound
Development of a mechanical testing system for a mandibular distraction wound
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DOI：
10.1054/ijom.2003.0424
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发表时间：
2003-10-01
影响因子：
2.4
通讯作者：
Kaban, LB
中科院分区：
文献类型：
--
作者：
Perrott, DH;Rahn, B;Kaban, LB
本研究的目的是开发一种力学测试系统来评估实验性猪下颌骨牵张成骨(DO)创面的硬度。该系统的设计是在不改变愈合下颌骨形态的情况下进行的。定制的夹具被设计成可以对尤卡坦小型猪半下颌骨进行悬臂弯曲测试。实验和对照半下颌骨被放置在夹具中，并固定近端节段。材料测试装置对前磨牙(牙合)面施加逐渐增加的向下力。施加的最大力为0.030 kN。每个半下颌骨的硬度值由力(KN)-位移(Mm)曲线的斜率表示。在机械测试之前和之后拍摄X线片，以显示牵张伤处的大体形态变化或可识别的骨折。24只小型猪接受了右侧下颌骨DO.，0d潜伏期和牵张速度分别为1，2和4 mm/d，形成12圈的间隙。在完成0、8、16和24天的中性固定后，分别为三种不同的牵张率分别处死两只动物进行机械测试。对照半下颌骨的硬度范围为0.018至0.317 kN/mm(中位数0.063；平均0.099+/-0.080)。实验侧下颌骨的硬度范围为0到0.025 kN/mm(中位数0.004；平均0.005)。在中性固定结束时测试的子集的僵硬在0.005到0.025之间(中位数0.011；平均0.012+/-0.011)。检测后X线片上未见明显的形态改变。结果表明，悬臂梁弯曲模型在不破坏下颌DO创面形态的前提下，可用于测试创面的硬度。
The purpose of this study was to develop a mechanical testing system to estimate stiffness of an experimental porcine mandibular distraction osteogenesis (DO) wound. The system was designed to function without changing the morphology of the healing mandible.A customized jig was designed to allow cantilever-bending tests of the Yucatan mini-pig hemi-mandible. Experimental and control hemi-mandibles were placed in the jig and the proximal segment was secured. A material testing unit applied progressively increasing downward force on the pre-molar occlusal surface. The maximum force applied was 0.030 kN. The stiffness value for each hemi-mandible was represented by the slope of the plot of force (kN) vs displacement (mm). Radiographs were taken before and after mechanical testing to demonstrate any gross morphologic changes or identifiable fractures across the distraction wound.A total of 24 mini-pigs underwent DO.of the right mandible with 0-day latency and distraction rates of 1, 2, and 4 mm per day resulting in a 12 turn gap. At the completion of 0, 8, 16, and 24 days of neutral fixation, two animals for each of three different distraction rates were sacrificed for mechanical testing. Stiffness of control hemi-mandibles ranged between 0.018 and 0.317 kN/mm (median 0.063; mean 0.099 +/- 0.080). Stiffness of experimental hemi-mandibles ranged between 0 and 0.025 kN/mm (median 0.004; mean 0.005). The subset that was tested at the end of neutral fixation had stiffness between 0.005 and 0.025 (median 0.011; mean 0.012 +/- 0.011). No morphologic changes were evident on the X-rays after testing. The results indicate that the cantilever-bending model is useful for testing stiffness of an experimental mandibular DO wound without destroying its morphology.