Biomechanical and tribological properties of the temporomandibular joint

Background and Objective: Osteoarthritis in the temporomandibular joint (TMJ-OA) is known as the end stage of TMJ disorders (TMDs), and most of TMJ-OA patients exhibit joint pain as a main symptom. TMJ-OA is a multifactorial disease, associated with articular cartilage breakdown and eventual joint destruction. Functional overloading and increased joint friction in the TMJ are recognized to induce degradation and abrasion of the joint components, leading to the onset and progression of TMJ-OA. Therefore, insight into the biomechanical and tribological properties of the articular components in the TMJ might contribute to better understanding of the etiology of TMJ degradation, leading to the development and progress of effective treatment remedy for TMJ-OA. The challenging project in TMJ biomechanics aims to identify biomechanical microenvironment in the TMJ, to develop the diagnosis system for TMDs, and to develop a new treatment remedy for TMDs including TMJ tissue engineering. Methods: The databases PubMed, MEDLINE, and Web of Science were searched to retrieve relevant articles published in English from January 2000 to December 2020 using the keywords “temporomandibular joint” “friction” “joint lubrication” and “tribology” to investigate the biomechanical and tribological properties of the TMJ. Key Content and Findings: The present review consists of three parts. Part I is a brief review of the biomechanical properties of the TMJ articular components. In Part II, the TMJ lubrication is explained from the viewpoint of the joint tribology. In the final remarks, the possibility of TMJ computed simulation will be discussed. Conclusions: Future studies with much efforts are required to measure and visualize the biomechanical microenvironment within the TMJ during mandibular movements in clinical aspect.