摘要
目的 :研究下颌髁突软骨的生物力学性质 ,探讨其功能意义。方法 :采用拉伸力学实验方法 ,结合FungYC二参数指数方程和关节软骨二相理论 ,对 8例猪颞下颌关节髁突软骨冠状方向和矢状方向的长方形试件共 5 2个进行单轴拉伸实验和分析。结果 :髁突软骨表现出明显的非线性特征 ,在矢状方向上其拉伸强度、拉伸刚度和能量吸收及拉伸应变分别为 2 92MPa、9 0 4MPa、6 0 2N·mm及 37 34 % ,而在冠状方向上各力学参数分别为 2 15MPa、6 5 5MPa、4 91N·mm及 41 12 % ,力学性能并不一致。结论 :髁突软骨是具有非线性粘弹性特征的生物二相体 ,力学性能表现出明显的各向异性 ,在矢状方向的抗拉伸能力更强。
Objective:To study the biomechanical properties of the mandibular condyle cartilage and determine its functional importance. Methods: Eight condyle specimens of the four pig temporomandibular joints were obtained by autopsy and stored in sealed plastic bags at 20℃. These pigs were healthy, aged 1 year ±2 months. In the coronal direction, 300μm wide, rectangular cartilage-bone specimens were prepared on the right condyles using specified knife. In the sagittal direction, rectangular cartilage bone specimens with the same width were obtained on the left condyles. Standard rectangular testing specimens were prepared from cartilage bone specimens in a microtome kept at 20℃ (300μm wide and 250μm thick). The specimens were inserted in a soft tissue uniaxial tensile test machine and immersed in a bath of Ringer′s solution at room temperature. Preconditioning of the specimens was carried out prior to the uniaxial tensile experiment and the specimens were elongated to failure with the constant strain rate (0 05mm/s). The resulting mean values were curved fitted with Fung′s two parameter (A,B) exponential stress strain equation using a nonlinear regression program. Results: The data obtained showed that a typical nonlinear biomechanical behavior of the condyle cartilage. Toe region and quasi linear zone were obvious on the experimental stress strain relation curve. Theoretically fitted parameter A and B were 0 47 and 4 13 (coronally) and 0 60 and 4 70 (sagittally). The sagittal specimens showed greater tensile stress (2 92 MPa), tensile stiffness (9 04 MPa), energy absorption (6 02 N·mm) but less tensile strain (37 34%) than that of the coronal specimens (2 15 MPa, 6 55MPa, 4 91 N·mm, and 41 12%). The differences were statistically significant (P<0 05). Conclusion: The mandibular condyle cartilage is a kind of biophasic material which shows nonlinear viscoelastic behavior, anistrophic characteristics in biomechanical function and high ability to resist tensile stress in the longitudinal direction.
出处
《华西口腔医学杂志》
CAS
CSCD
北大核心
2000年第2期85-87,共3页
West China Journal of Stomatology
基金
甘肃省青年科学基金! (编号ZS981 A2 3 60Y)
关键词
髁突软骨
拉伸力学
各向异性
颞下颌关节
condyle cartilage tensile mechanics anistrophy temporomandibular joint
