Conci Ricardo Augusto, Tomazi Flavio Henrique Silveira, Noritomi Pedro Yoshito, da Silva Jorge Vicente Lopes, Fritscher Guilherme Genehr, Heitz Claiton
Specialist and Master of Oral and Maxillofacial Surgery, PhD Candidate in Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial Surgery, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
Specialist and Master Candidate in Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial Surgery, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
J Oral Maxillofac Surg. 2015 Jul;73(7):1321-7. doi: 10.1016/j.joms.2015.01.037. Epub 2015 Feb 11.
To compare the mechanical stress on the mandibular condyle after the reduction and fixation of mandibular condylar fractures using the neck screw and 2 other conventional techniques according to 3-dimensional finite element analysis.
A 3-dimensional finite element model of a mandible was created and graphically simulated on a computer screen. The model was fixed with 3 different techniques: a 2.0-mm plate with 4 screws, 2 plates (1 1.5-mm plate and 1 2.0-mm plate) with 4 screws, and a neck screw. Loads were applied that simulated muscular action, with restrictions of the upper movements of the mandible, differentiation of the cortical and medullary bone, and the virtual "folds" of the plates and screws so that they could adjust to the condylar surface. Afterward, the data were exported for graphic visualization of the results and quantitative analysis was performed.
The 2-plate technique exhibited better stability in regard to displacement of fractures, deformity of the synthesis materials, and minimum and maximum tension values. The results with the neck screw were satisfactory and were similar to those found when a miniplate was used.
Although the study shows that 2 isolated plates yielded better results compared with the other groups using other fixation systems and methods, the neck screw could be an option for condylar fracture reduction.
根据三维有限元分析，比较使用颈部螺钉及其他两种传统技术对下颌髁突骨折进行复位和固定后，下颌髁突上的机械应力。
创建下颌骨的三维有限元模型，并在计算机屏幕上进行图形模拟。该模型采用三种不同技术进行固定：一块带有4枚螺钉的2.0毫米钢板、两块（一块1.5毫米钢板和一块2.0毫米钢板）各带有4枚螺钉的钢板以及一枚颈部螺钉。施加模拟肌肉作用的载荷，同时限制下颌骨的向上运动，区分皮质骨和髓质骨，并对钢板和螺钉进行虚拟“折叠”，使其能够适应髁突表面。之后，导出数据以对结果进行图形可视化，并进行定量分析。
在骨折移位、合成材料变形以及最小和最大张力值方面，双钢板技术表现出更好的稳定性。颈部螺钉的结果令人满意，与使用微型钢板时的结果相似。
尽管该研究表明，与使用其他固定系统和方法的其他组相比，两块单独的钢板产生了更好的结果，但颈部螺钉可作为髁突骨折复位的一种选择。
