Sato Fábio Ricardo Loureiro, Asprino Luciana, Consani Simonides, de Moraes Márcio
Oral and Maxillofacial Surgery Department, Campinas State University-UNICAMP, Piracicaba Dental School, Piracicaba, São Paulo, Brazil.
J Oral Maxillofac Surg. 2010 Jan;68(1):160-6. doi: 10.1016/j.joms.2009.09.004.
The aim of the present study was to comparatively evaluate the resistance and tension areas created after load incidence in different varieties of sagittal split ramus osteotomy fixation techniques.
Fifty synthetic polyurethane hemimandible replicas were subjected to linear loading tests to evaluate 4 fixation techniques of the sagittal split ramus osteotomy using 2-mm system plates and screws. The hemimandibles were fixed with three 90 degrees linear screws, three 60 degrees linear screws, 3 screws in a reversed L arrangement, and one titanium miniplate. Each group was subjected to linear loading using an Instron 4411 servohydraulic mechanical testing unit. The load peak value and peak displacement were measured. Another 4 hemimandible replicas were made of photoelastic resin and subjected to photoelastic analysis after linear loading with a 3-mm displacement.
The results of the mechanical tests showed statistically significant differences between the fixation groups. The linear 90 degrees fixation and the reversed L arrangement presented with greater loading resistance, followed by the linear 60 degrees fixation and miniplates. In relation to the stress distribution in the photoelastic analysis, the fringes were concentrated near the osteotomy and to the lower part of the mandible in the linear 90 degrees -screw system and reversed L arrangement. In the case of the linear 60 degrees screws, most fringes were located around and between the screws. In the case of the miniplates, the fringes were concentrated around the screws near the osteotomy and more distally.
Under the conditions tested, the linear 90 degrees and reversed L arrangements provided the most favorable behavior.
本研究的目的是比较评估不同类型的矢状劈开下颌支截骨固定技术在加载后产生的阻力和张力区域。
五十个合成聚氨酯半下颌骨复制品接受线性加载测试，以评估使用2毫米系统钢板和螺钉的矢状劈开下颌支截骨的4种固定技术。半下颌骨用三个90度线性螺钉、三个60度线性螺钉、呈倒L形排列的3个螺钉和一个钛微型钢板固定。每组使用Instron 4411伺服液压机械测试单元进行线性加载。测量载荷峰值和峰值位移。另外4个半下颌骨复制品由光弹性树脂制成，并在3毫米位移的线性加载后进行光弹性分析。
力学测试结果显示固定组之间存在统计学上的显著差异。90度线性固定和倒L形排列具有更大的抗载能力，其次是60度线性固定和微型钢板。关于光弹性分析中的应力分布，条纹集中在截骨部位附近以及90度线性螺钉系统和倒L形排列的下颌骨下部。对于60度线性螺钉，大多数条纹位于螺钉周围和之间。对于微型钢板，条纹集中在截骨部位附近和更远端的螺钉周围。
在测试条件下，90度线性和倒L形排列表现出最有利的性能。
