Piracicaba Dental School, Oral and Maxillofacial Surgery (Department of Oral Diagnosis), (Head: Jose Ricardo de Albergaria-Barbosa), State University of Campinas e UNICAMP, P.O. Box 52, Piracicaba, Sao Paulo, 13414-903, Brazil; Centro de Investigaciones del Colegio Odontológico (CICO), Institución Universitaria Colegios de Colombia, Bogotá, Colombia.
Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Piracicaba, São Paulo, Brazil.
J Craniomaxillofac Surg. 2019 Jul;47(7):1015-1019. doi: 10.1016/j.jcms.2019.01.007. Epub 2019 Jan 21.
To evaluate three rigid, stable fixation methods for sagittal split ramus osteotomy (SSRO), using finite element analysis. The hypothesis is that a customized miniplate presents better stress concentration and distribution.
A 3D model of a hemimandible was created, and a 10-mm-advancement SSRO was simulated and fixed as follows: 3-DCP group - one custom miniplate fixed by eight screws; 4-H2P group - two miniplates of four holes each, fixed by eight screws; and 6-H2P group - two miniplates of six holes each fixed by 12 screws. After a vertical loading of 100 N, the values for von Mises stress, modified von Mises stress, and maximum and minimum principal stresses were measured.
The area of maximum principal stress was similar for the three groups - located in the upper miniplate, in the screw near the proximal segment osteotomy. The maximum von Mises stresses were 1580.4 MPa, 1005 MPa, and 977.56 MPa for the 3DCP, 4-H2P, and 6-H2P groups, respectively, showing an allowable displacement of 2.57 mm, 1.62 mm, and 1.52 mm for the 3DCP, 4-H2P, and 6-H2P groups, respectively.
The customized miniplate did not present better stress distribution than two commonly used types of fixation. Fixation with two straight miniplates, either with four or six holes, offers adequate resistance for 10 mm linear advancements.
通过有限元分析评估三种用于矢状劈开截骨术（SSRO）的刚性、稳定固定方法。假设定制微型板具有更好的应力集中和分布。
创建了一个半下颌骨的 3D 模型，并模拟和固定了 10mm 推进的 SSRO，具体方法如下：3-DCP 组-一个定制的微型板用 8 个螺钉固定；4-H2P 组-两个每个有四个孔的微型板，用 8 个螺钉固定；6-H2P 组-两个每个有六个孔的微型板用 12 个螺钉固定。在垂直加载 100N 后，测量了 von Mises 应力、修正 von Mises 应力、最大和最小主应力的值。
三组的最大主应力区域相似-位于上微型板、靠近近段骨切开术的螺钉附近。3DCP、4-H2P 和 6-H2P 组的最大 von Mises 应力分别为 1580.4MPa、1005MPa 和 977.56MPa，3DCP、4-H2P 和 6-H2P 组的允许位移分别为 2.57mm、1.62mm 和 1.52mm。
定制微型板的应力分布并不优于两种常用的固定类型。用两个直微型板固定，每个微型板有四个或六个孔，可提供 10mm 线性推进的足够阻力。
