Joint · Jaw

Temporomandibular joint

Articulatio temporomandibularis

The jaw joint, where the condyle of the mandible meets the temporal bone just in front of the ear. A fibrocartilaginous disc sits between the two surfaces and divides the joint into an upper and a lower compartment, which lets the jaw do two different things at once: the lower compartment hinges the jaw open, and the upper compartment slides the condyle forward. Both sides must work as a pair — you cannot move one jaw joint without the other — which is why jaw problems are so often felt on both sides, and why the chewing muscles, the neck and the ear region are all part of the same picture.