Araujo M M, Waite P D, Lemons J E
Department of Oral and Maxillofacial Surgery, University of Alabama at Birmingham Medical Center, Birmingham, AL, USA.
J Oral Maxillofac Surg. 2001 Sep;59(9):1034-9; discussion 1039-40. doi: 10.1053/joms.2001.25832.
The purpose of this study was to compare the biomechanical characteristics of metallic and polymeric fixation systems using a 3-dimensional skull model to simulate clinical conditions of maxillary advancement and loading.
Standard titanium, prebent titanium, and resorbable plates and mesh were applied to surgically altered polyurethane skulls. The constructs were loaded using an Instron machine (Instron Inc, Canton, MA) in anterior-posterior (AP) and inferior-superior (IS) directions. The load displacement, load to failure, and deformation magnitudes and modes of failure were recorded. Statistical studies included analysis of variance (ANOVA) at P <.05.
Elastic stiffness was different among groups in the AP direction, but no significant difference was found in the IS direction. The IS loading direction load displacement (stiffness) was significantly greater than that on AP loading. The maximum load for permanent deformation was larger in the AP direction, while the maximum load for breaking was larger in the IS direction.
The overall evaluation of the model and test analyses supported the relative value of this in vitro system and study procedure. All systems showed load capacity magnitudes above 285 N (64 lbs) and more elastic resistance in the IS direction. The resorbable systems showed lower elastic stiffness compared with the titanium systems, but they appear to be adequate for fixation and withstanding the forces of mastication.
本研究的目的是使用三维颅骨模型比较金属和聚合物固定系统的生物力学特性，以模拟上颌前移和加载的临床情况。
将标准钛板、预弯钛板以及可吸收板和网片应用于手术改变后的聚氨酯颅骨。使用英斯特朗试验机（英斯特朗公司，马萨诸塞州坎顿）在前-后（AP）和下-上（IS）方向对构建体进行加载。记录载荷位移、破坏载荷以及变形大小和破坏模式。统计研究包括P <.05时的方差分析（ANOVA）。
在AP方向上，各组之间的弹性刚度不同，但在IS方向上未发现显著差异。IS加载方向的载荷位移（刚度）明显大于AP加载方向。永久变形的最大载荷在AP方向上更大，而断裂的最大载荷在IS方向上更大。
模型和测试分析的总体评估支持了该体外系统和研究程序的相对价值。所有系统的承载能力大小均高于285 N（64磅），并且在IS方向上具有更大的弹性阻力。与钛系统相比，可吸收系统的弹性刚度较低，但它们似乎足以用于固定并承受咀嚼力。
