Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp/SJC), São Paulo, Brazil.
Department of Dental Materials Science, Academic Center for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
Dent Traumatol. 2020 Dec;36(6):662-669. doi: 10.1111/edt.12577. Epub 2020 Jun 23.
BACKGROUND/AIMS: There is a lack of data regarding the mechanical responses of the temporo-mandibular joints during an impact to the orofacial region. The aim of this study was to analyze the biomechanical effects of wearing a mouthguard (MG) on the impact response of the mandibular condyle and articular disk according to the type of occlusion. The hypothesis was that the MG would minimize the effect in those structures, regardless of the occlusion type.
Using modeling software, a human skull with jaw, teeth and articular disk was created. The models were divided according to the occlusion type (Class I, II, or III) and the presence of a mouthguard (with or without). The geometries were exported to analysis software, and the materials were considered ideal. Fixation occurred at the base of the foramen magnum. The load (0-500N, 1s) was applied to the upper central incisors with a steel ball. Maximum principal stress and Von Mises results (MPa) were obtained in the mandibular condyle and articular disk. Minimum principal stress and maximum shear stresses were also recorded in the articular disk.
For both structures, the MG caused a decrease in stress concentration regardless of the occlusion and stress criteria. The condyle neck was the most tensile-stressed area while for the articular disk, both the superior and inferior surfaces were the most stressed areas. The highest stress peaks in the disk were found for compression followed by tensile and then shear stress.
This biomechanical analysis of the effects of using a mouthguard exhibited considerably decreased stresses on the mandibular condyle and articular disk, regardless of the occlusion type.
背景/目的：关于颌面部受到冲击时颞下颌关节的机械反应，目前数据有限。本研究旨在分析佩戴口腔防护用具（MG）对口颌部冲击响应时下颌骨髁突和关节盘的生物力学影响，并根据咬合类型进行分析。研究假设是 MG 会最小化这些结构的影响，而与咬合类型无关。
使用建模软件创建了带有颌骨、牙齿和关节盘的人类头骨模型。根据咬合类型（I 类、II 类或 III 类）和是否佩戴 MG 将模型进行分组。将几何图形导出到分析软件中，并将材料视为理想状态。在枕骨大孔底部进行固定。用钢球对上中切牙施加（0-500N，1s）的负荷。在髁突和关节盘中获得最大主应力和 Von Mises 结果（MPa）。还记录了关节盘中的最小主应力和最大剪应力。
对于两种结构，无论咬合和应力标准如何，MG 都会降低应力集中。髁突颈部是拉伸应力最大的区域，而对于关节盘，上下表面是受力最大的区域。盘上的最高应力峰值出现在压缩之后是拉伸，然后是剪切应力。
本研究对口颌部使用 MG 的生物力学效应进行了分析，结果表明无论咬合类型如何，髁突和关节盘的应力均显著降低。
