Mechanical Properties of TMJ Disc Cells Measured by Atomic Force Microscopy

The temporomandibular joint (TMJ) is a load bearing joint with unique articular structure. The TMJ disc, a fibrocartilaginous tissue, is a major component of jaw function by serving stress distribution and lubrication in the joint. The TMJ disc pathophysiology, such as disc derangement and degeneration, is central to many TMJ disorders affecting a large population. It is generally believed that pathological mechanical loading, such as sustained mechanical loading in jaw clenching and traumatic impact, is the leading cause of TMJ disc derangement [1]. However, the exact mechanism, especially at the cellular level, has not been established. TMJ disc cells, fibrochondrocyte-like cells, respond to chemical and mechanical signals and regulate the physiology and pathology of the disc. However, little is known of the cellular mechanical properties in TMJ disc. The objective of this study is to determine the mechanical properties of a single TMJ disc cell using atomic force microscopy (AFM).