Basic Mechanics Lab, Sichuan University, Chengdu 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin, 644600, China.
Key Lab for Biomechanical Engineering of Sichuan Province, Sichuan University, Chengdu 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin, 644600, China.
Comput Methods Programs Biomed. 2022 Jan;213:106526. doi: 10.1016/j.cmpb.2021.106526. Epub 2021 Nov 12.
Temporomandibular disorders (TMD) represent a group of diseases occurred in the temporomandibular joint (TMJ) and its surrounding tissues. In epidemiological studies, up to 75% of adults have shown at least one sign of temporomandibular disorders during their examinations. The incongruous biomechanical environment in the TMJ is the main pathogenic factor of TMD. This study attempts to determine the mechanical differences in different groups of TMD patients through biomechanics and to explain the mechanical pathogenesis of TMD according to various cases.
Eleven control subjects and eleven TMD patients were selected and divided into three groups: the control group, bilateral TMD group, and unilateral TMD group. The contact stresses of the articular discs, condyles and temporal bones were analyzed using finite element method and statistical analysis of variance.
The results indicated that the contact stresses in the joints with TMD were significantly greater in the Bi-Group (Bilateral TMD patients) compared to the Control-Group. The TMD side always exhibited greater stresses in the Uni-Group [Unilateral TMD patients) under various conditions (clenching on the TMD side or asymptomatic side). The greatest stress of all the groups occurred at the contralateral side with TMD when clenching on the asymptomatic side.
Excessive protection would lead to greater stress on the affected side and increased TMD risk on the asymptomatic side. Clinically, the abnormal stress distributions of the disc represented poor buffering and articular clicking. The asymmetric distributions of the articular fossa manifested the deviation of mouth opening or inconsistent TMJ loading.
颞下颌关节紊乱症（TMD）是一组发生于颞下颌关节及其周围组织的疾病。在流行病学研究中，高达 75%的成年人在检查中至少出现过一种颞下颌关节紊乱症的迹象。颞下颌关节中不协调的生物力学环境是 TMD 的主要致病因素。本研究试图通过生物力学确定不同 TMD 患者群体的力学差异，并根据各种病例解释 TMD 的力学发病机制。
选取 11 名正常对照组和 11 名 TMD 患者，分为三组：对照组、双侧 TMD 组和单侧 TMD 组。采用有限元法和方差分析对关节盘、髁突和颞骨的接触应力进行分析。
结果表明，TMD 关节的接触应力在双侧 TMD 患者的 Bi-Group 中明显大于对照组。在各种情况下（TMD 侧或无症状侧咬牙），单侧 TMD 患者的 TMD 侧始终表现出更大的应力。所有组中最大的应力发生在无症状侧咬牙时 TMD 的对侧。
过度保护会导致患侧承受更大的压力，无症状侧的 TMD 风险增加。临床上，关节盘异常的应力分布代表了较差的缓冲作用和关节弹响。关节窝的不对称分布表现为开口偏斜或 TMJ 加载不一致。
