Rosacea

The temporomandibular joint (TMJ) connects your jaw to the side of your head. When it works well, it enables you to talk, chew and yawn. For people with TMJ dysfunction, problems with the joint and muscles around it may cause Pain that travels through the face, jaw or neck Stiff jaw muscles Limited movement or locking of the jaw Painful clicking or popping in the jaw.[Ref 1]

[Ref 1] http://www.nlm.nih.gov/medlineplus/temporomandibularjointdysfunction.html