Murakami Kazuhiro, Yamamoto Kazuhiko, Sugiura Tsutomu, Horita Satoshi, Matsusue Yumiko, Kirita Tadaaki
Postdoctoral Fellow, Department of Oral and Maxillofacial Surgery, Nara Medical University, Kashihara, Japan.
Associate Professor, Department of Oral and Maxillofacial Surgery, Nara Medical University, Kashihara, Japan.
J Oral Maxillofac Surg. 2017 Jun;75(6):1239.e1-1239.e11. doi: 10.1016/j.joms.2017.02.014. Epub 2017 Feb 24.
This study was performed to evaluate stresses in various types of plates placed for a virtually reduced unilateral condylar fracture of the mandible using computed tomography-based 3-dimensional finite element (FE) models of a patient to select the optimal plate system.
A computed tomography-based FE model of the mandible of a patient with a unilateral condylar fracture was constructed. The fracture was virtually reduced and fixed with 1 straight titanium plate; 2 straight titanium plates; 2 straight poly-L-lactic acid plates; and 4-hole (box), 5-hole (strut), and 7-hole (lambda) condylar plates. Stresses developing in these plates were analyzed by applying 478.1 N of bite force at the first molar of the contralateral side of the mandible.
The magnitudes of tensile stress were within the tensile strength in all types of plates. However, the magnitudes of compressive stress in 1 straight titanium plate and 2 straight poly-L-lactic acid plates were beyond the compressive strength. The tensile and compressive stresses of the 5-hole (strut) plate were the smallest among the 3 types of condylar plates.
Fixation by 2 straight titanium plates or any type of condylar plate was biomechanically indicated for the condylar fracture of this patient. Among these plates, the 5-hole (strut) plate was considered optimal. FE analysis is useful in selecting the optimal fixation method in the individual patient.
本研究旨在利用基于计算机断层扫描的患者三维有限元（FE）模型，评估用于虚拟复位的单侧下颌骨髁突骨折的各类接骨板的应力情况，以选择最佳接骨板系统。
构建一名单侧髁突骨折患者下颌骨的基于计算机断层扫描的有限元模型。将骨折虚拟复位并用1块直形钛板、2块直形钛板、2块直形聚-L-乳酸接骨板以及4孔（盒形）、5孔（支柱形）和7孔（λ形）髁突接骨板进行固定。通过在下颌对侧第一磨牙施加478.1 N的咬合力来分析这些接骨板中产生的应力。
所有类型接骨板中的拉应力大小均在拉伸强度范围内。然而，1块直形钛板和2块直形聚-L-乳酸接骨板中的压应力大小超出了抗压强度。在3种类型的髁突接骨板中，5孔（支柱形）接骨板的拉应力和压应力最小。
对于该患者的髁突骨折，从生物力学角度表明应采用2块直形钛板或任何类型的髁突接骨板进行固定。在这些接骨板中，5孔（支柱形）接骨板被认为是最佳的。有限元分析有助于为个体患者选择最佳固定方法。
