Is there first aid for a dislocated jaw?

If your jaw is dislocated, do not try to force it back in - come to a dental clinic or emergency room as soon as possible. For first aid, 1) stop talking and opening your mouth further, and let your jaw relax, 2) support the jaw gently with a towel to keep it still, and 3) let saliva drain rather than swallowing it. The sooner it is treated the less the muscles have tensed, which makes repositioning easier; it becomes harder as time passes. Repeated (habitual) dislocation needs TMJ treatment, so please arrange a separate consultation.