Gealh Walter Cristiano, Costa Julyano Vieira, Ferreira Geovane Miranda, Iwaki Filho Liogi
MSc Student, Dental School, State University of Sao Paulo (Julio de Mesouita Filho) UNESP-Arasatuba, Campo Mourão, Paraná, Brazil.
J Oral Maxillofac Surg. 2009 Apr;67(4):738-43. doi: 10.1016/j.joms.2008.06.034.
The objective of this study was to carry out a comparative evaluation of the mechanical resistance of 2 rigid internal fixation techniques for fractures of the mandibular condyle using miniplates.
Forty polyurethane resin replicas of human hemimandibles were used. The hemimandibles were sectioned to simulate a high subcondylar fracture and then stabilized with 2 fixing techniques using 2.0-mm system plates and screws. The fixation techniques were 2 separate 4-hole plates with 8 screws, and 2 overlaid 4-hole plates with 4 screws. Each system was submitted to load tests, with the application of the load in mediolateral and anteroposterior directions in an Instron 4411 universal assay machine (Instron, Norwood, MA).
Load values and peak displacement were measured. Means and standard deviations were evaluated by analysis of variance (P < .05) and Tukey tests, in which it was verified that the antero-posterior peak load value was affected by the arrangement of the plates on the models, although no differences were observed between the groups for the mediolateral peak load. The arrangement of the plates did not have any influence on peak displacement. Similarly, the final value of the mediolateral load was not affected by the arrangement of the plates on the model.
The experimental model with 2 separate plates was statistically superior to the model with 2 overlaid plates only in relation to anteroposterior peak load. Despite showing superiority in mediolateral peak load and peak displacement, there was no statistical difference between the groups for these parameters.
本研究的目的是使用微型钢板对下颌髁突骨折的两种坚固内固定技术的力学阻力进行比较评估。
使用40个人类半下颌骨的聚氨酯树脂复制品。将半下颌骨切开以模拟髁突下高位骨折，然后使用2.0毫米系统钢板和螺钉通过两种固定技术进行固定。固定技术分别是使用8枚螺钉的2块单独的4孔钢板，以及使用4枚螺钉的2块重叠的4孔钢板。每个系统都在Instron 4411通用试验机（Instron，诺伍德，马萨诸塞州）上进行加载测试，在内外侧和前后方向施加负荷。
测量负荷值和峰值位移。通过方差分析（P <.05）和Tukey检验评估均值和标准差，结果证实，尽管内外侧峰值负荷在两组之间未观察到差异，但前后峰值负荷值受模型上钢板排列的影响。钢板的排列对峰值位移没有任何影响。同样，内外侧负荷的最终值不受模型上钢板排列的影响。
仅在前后峰值负荷方面，具有2块单独钢板的实验模型在统计学上优于具有2块重叠钢板的模型。尽管在内外侧峰值负荷和峰值位移方面显示出优势，但这些参数在两组之间没有统计学差异。
