Depth-dependent patterns in shear modulus of temporomandibular joint cartilage correspond to tissue structure and anatomic location
Depth-dependent patterns in shear modulus of temporomandibular joint cartilage correspond to tissue structure and anatomic location
复制标题
颞下颌关节软骨剪切模量的深度依赖模式对应于组织结构和解剖位置
DOI：
10.1016/j.jbiomech.2021.110815
复制
发表时间：
2021
影响因子：
2.4
通讯作者：
Bonassar, Lawrence J.
中科院分区：
文献类型：
--
作者：
Gologorsky, Cassandra J.;Middendorf, Jill M.;Cohen, Itai;Bonassar, Lawrence J.
为了充分了解TMJ软骨退化和适当的修复机制，了解TMJ软骨的天然结构-力学关系以及组织中可能发生的任何局部变化是至关重要的。在这里，我们使用共聚焦弹性成像和数字图像相关测量的深度依赖性剪切特性以及TMJ软骨的结构特性在髁突上的不同解剖位置，以确定剪切力学和结构的深度依赖性变化。我们发现，在每个解剖位置的样本表现出定性相似的剪切模量曲线作为深度的函数。在每个样品中，观察到四个不同的机械行为区域，剪切模量值跨越3-5个数量级。然而，剪切模量曲线的定量特征因解剖位置而异，特别是区域大小和位置，其中最显著的区域宽度变化发生在纤维软骨表面层（区域1）。这种解剖学上的变化表明，不同的位置上的颞下颌关节髁状突可能发挥独特的力学作用，颞下颌关节的功能。此外，在机械数据中识别的区域在逐个样本的基础上对应于在结构数据中识别的区域，表明TMJ软骨的已知结构区域也可能在TMJ功能中发挥独特的机械作用。
To fully understand TMJ cartilage degeneration and appropriate repair mechanisms, it is critical to understand the native structure-mechanics relationships of TMJ cartilage and any local variation that may occur in the tissue. Here, we used confocal elastography and digital image correlation to measure the depth-dependent shear properties as well as the structural properties of TMJ cartilage at different anatomic locations on the condyle to identify depth-dependent changes in shear mechanics and structure. We found that samples at every anatomic location showed qualitatively similar shear modulus profiles as a function of depth. In every sample, four distinct zones of mechanical behavior were observed, with shear modulus values spanning 3–5 orders of magnitude across zones. However, quantitative characteristics of shear modulus profiles varied by anatomic location, particularly zone size and location, with the most significant variation in zonal width occurring in the fibrocartilage surface layer (zone 1). This anatomic variation suggests that different locations on the TMJ condyle may play unique mechanical roles in TMJ function. Furthermore, zones identified in the mechanical data corresponded on a sample-by-sample basis to zones identified in the structural data, indicating the known structural zones of TMJ cartilage may also play unique mechanical roles in TMJ function.