My PT gave me the following tips; please use them carefully and don't push yourself to where you hurt yourself more than you relax yourself:
Do each ten times, and only to the point where the pain is not "this is WRONG" pain but "okay this stretch is manageable":
slowly open wide and close your mouth
slowly push your lower jaw forward and back again
slowly shift your lower jaw to the left, to the right, and back to center again
I usually slowly count to three or for for each movement, and try to time it with nice slow breathing. So, slowly open wide & breathe in (ideally through the nose though, if you can) while counting to three or four, then slowly close & breathe out while counting to three or four. Fluid, continuous movements, not jerky ones, and be gentle and don't force things.
My PT said this is to help the jaw muscles remember how they *can* move. He recommended massages too! He said if your jaw clicks while doing those moves, it's not worrisome in and of itself, but if the click is accompanied by pain, ease up on how much you move your jaw, or stop with the move that caused the click, and try one of the others.
AFTERWARDS (and you really do need to do the movements of the first list first!!)
loosen your lower jaw (your teeth must not touch), put the knuckles of your left hand to the left side of your lower jawbone, and gently push towards your right, to stretch the left side of your jaw muscles. Hold for a count of five to ten slow breaths - for me, I notice a shift in the muscles, to where they let loose a bit, around the seventh or eighth breath; see how this works for you.
do the same with the right hand pushing left.
extend the thumb and first finger of your stronger hand to an L shape. Put it on your chin so that the chin protrusion is below the "hinge" of the L. Open your mouth slowly, and then use your hand to open it a bit wider and stretch the opening muscles on both sides. Hold for five to ten slow breaths. For a second step, you can add resistance: push your lower jaw upwards while at the same time pushing downwards with your hands. Only small incremements!!! LIke, fractions of inches! And only for one or two seconds, before you release again.
Please be careful and gentle with all these steps. No jerky motions, don't go past the "okay stretch" point to the "fuck this HURTS" point, and if you have a history of dislocating your jaw, please proceed carefully or skip this entirely and only do the movements described in the first list.
I often do these in bed at night, or randomly while I watch TV or something, or take a break at work to do them (my co-workers are used to it by now 😅).
