The temperomandibular joint (TMJ) is the movable joint between the mandible (lower jaw bone) and part of the cranium called the temporal bone. It is a complicated joint and the two hard bone surfaces are separated by a circular piece of softer cartilage which acts like a cushion.

Look at the model to see the lower jaw moving up and down, sideways and forwards. This joint is in constant use during chewing, swallowing, talking, and laughing. Some of these movements involve rotation of the joint and some are sliding movements.