山羊颞下颌关节盘生物力学的多维测量及定量分析

Comprehensive measurement and quantification of bio-mechanical properties of the temporomandibular joint disc

目的从压缩、拉伸、循环压缩、循环拉伸、蠕变、摩擦等多维度测量分析颞下颌关节盘的生物力学性能,完善颞下颌关节盘的力学检测体系。方法在市场统一购置新鲜羊头15只(2.5~3.0 kg),均为普通饲养山羊(9~12个月龄,体质量18~21 kg),雌雄不限,于处死后30 min内解剖出双侧关节盘(共计30枚)。参照黏弹性材料的力学测试国标,将山羊颞下颌关节盘按不同检测要求制样,模拟体内条件进行实验,使用万能材料试验机测试颞下颌关节盘的各项生物力学性能。结果颞下颌关节盘具备一定的抗压缩[(8.41±2.12)MPa]、抗拉伸[(9.54±3.26)MPa]性能,但在超过生理载荷后,即发生不可逆性破坏,丧失原有力学属性。颞下颌关节盘在持续应力(0.5或3.0 MPa)作用下发生明显蠕变松弛(30%);其表面摩擦系数为0.015±0.011,低于一般黏弹性材料的表面摩擦值。结论颞下颌关节盘是具有一定抗压-抗拉性能、表面在润湿状态下非常光滑的生物黏弹体。

Objective To comprehensively investigate the biomechanical properties of the temporomandibular joint(TMJ)disc and to perfect the mechanical testing system of the TMJ disc by conducting tests of compression,tension,cyclic compression,cyclic tension,creep and friction.Methods Fifteen fresh goat heads(weighing 2.5-3.0 kg)were purchased from the market.They were all ordinary goats(9-12 months old,body weighing 18-21 kg)regardless of gender.Bilateral articular discs(a total of 30)were dissected within 30 minutes after execution.According to the national standard for mechanical testing of viscoelastic materials,fresh TMJ disc specimens of goat were prepared and tests were carried out in physiological conditions.The universal mechanical testing machine was utilized to test biomechanical properties of TMJ discs.Results The compressive modulus of TMJ discs was(8.41±2.12)MPa and the tensile modulus was(9.54±3.26)MPa.The mechanical characteristics would be irreversibly altered once the load exceeded the physiological range.In addition,it underwent apparent creep relaxation under continuous strain(0.5 MPa or 3.0 MPa)and the surface friction coefficient of the TMJ discs(0.015+0.011)was much lower than that of general viscoelastic materials.Conclusions The TMJ disc was a bio-viscoelastic structure with excellent tensile and compressive properties and its surface was extremely smooth in wet conditions.