Ponvel Keerthana, Panneerselvam Elavenil, Balasubramanian Sasikala, Krishna Kumar Raja V B
Department of Oral and Maxillofacial Surgery, SRM Dental College and Hospital, Ramapuram Campus, Ramapuram, Chennai 600089, Tamil Nadu, India.
Department of Oral and Maxillofacial Surgery, SRM Dental College and Hospital, Ramapuram Campus, Ramapuram, Chennai 600089, Tamil Nadu, India.
Chin J Traumatol. 2019 Oct;22(5):261-269. doi: 10.1016/j.cjtee.2019.08.001. Epub 2019 Aug 9.
The fractures of anterior mandible are subject to severe torsional forces due to muscles acting in opposite directions. 3D miniplate has been suggested as a good alternative by some researchers. However, finite element model (FEM) studies indicate that labio-inferior positioning of two miniplates perpendicular to each other offers better stability as compared to labial positioning. This study aims at combining the advantages of a single 3D miniplate and labio-inferior positioning of two conventional miniplates, which was assessed by finite element analysis along with a pilot clinical trial.
Two FEM models were created using CT data of a 24-year-old patient with Angle class I occlusion: control model with labial plating and study model with labio-inferior plating. The models were processed with MIMICS® (materialise, Leuven, Belgium), CATIA® (Dassault Systemes) and finite element analysis softwares. Parameters adopted for analysis were (1) displacement (mm) of fracture fragments during each screw fixation, (2) lingual splay and post fixation stability of fracture fragments with masticatory load, and (3) stress distribution (MPa) across fracture fragments. Moreover, a pilot clinical trial including five patients with anterior mandible fracture was conducted. The fractures were managed by intraoral open reduction and 3D miniplate fixation in labio-inferior position. Intraoperative interfragmentary gap, post fixation lingual splay and radiographic fracture union and complications were assessed clinically.
Labio-inferior plating demonstrated less displacement (mm) of fracture fragments during screw fixation (0.059 vs. 0.079) as well as after application of masticatory load (1.805 vs. 1.860). Negligible lingual splay and less stress distribution (MPa) across fracture fragments (1.860 vs. 1.847) were appreciated in the study group as compared to control group. Clinical trial support the favorable outcome related to intraoperative and postoperative assessment parameters.
FEM analysis and clinical trial reveal better results with labio-inferior positioning of 3D miniplate when compared to labial positioning.
由于肌肉作用方向相反，下颌前部骨折承受严重的扭转力。一些研究人员建议使用三维微型钢板作为一种很好的替代方法。然而，有限元模型（FEM）研究表明，与唇侧定位相比，两个相互垂直的微型钢板的唇下定位提供了更好的稳定性。本研究旨在结合单个三维微型钢板和两个传统微型钢板唇下定位的优点，并通过有限元分析和一项初步临床试验进行评估。
使用一名24岁安氏I类咬合患者的CT数据创建两个有限元模型：唇侧钢板固定的对照模型和唇下钢板固定的研究模型。这些模型使用MIMICS®（Materialise，比利时鲁汶）、CATIA®（达索系统）和有限元分析软件进行处理。分析采用的参数为：（1）每个螺钉固定过程中骨折碎片的位移（mm）；（2）咀嚼负荷下骨折碎片的舌侧张开和固定后稳定性；（3）骨折碎片上的应力分布（MPa）。此外，进行了一项包括五名下颌前部骨折患者的初步临床试验。骨折通过口内切开复位和唇下位置的三维微型钢板固定进行处理。术中评估骨折块间间隙、固定后舌侧张开情况，并通过影像学评估骨折愈合及并发症情况。
唇下钢板固定在螺钉固定过程中（0.059对0.079）以及施加咀嚼负荷后（1.805对1.860）骨折碎片的位移（mm）更小。与对照组相比，研究组骨折碎片的舌侧张开可忽略不计，且骨折碎片上的应力分布（MPa）更小（1.860对1.847）。临床试验支持了与术中及术后评估参数相关的良好结果。
有限元分析和临床试验表明三维微型钢板唇下定位比唇侧定位效果更好。
