For tension in the jaw, I've found inverting my body to be very helpful. I practice yoga asana failry regularly, and reversing the blood flow to my head REALLY helps me relax the muscles of my face...plus, it's great for the adrenals and lymphs.
One simple inversion is a forward bend. You place your feet hip distance apart with your heels slightly open outward. You can also place your hands on your hips, squeezing your elbows in to the center of your back. Bend the knees, and take big breath in. Then as you exhale, fold forward leading with your heart. The goal is to place your ribs on the thighs so you might need to deeply bend your knees to achieve this. Simultaneously, you keep your spine long, the back straight. This supports the bend so that you can safely relax and experience the benefit of increased blood flow and energy.
Once here, press the inner and outer edges of your feet into the earth. If your hands are on your hips, you can choose to keep them there, place them on the ground in front of you, or take each hand to the opposite elbow to hang the arms down toward the floor. Wherever you are, relax your neck and head COMPLETELY. The weight of the head (like a bowling ball) will gently stretch your spine long. And given the fleixiblity of our hamstrings, you can also try to straighten your legs but this is not necessary. Nod your head into a mini "yes" or side to side in a mini "no". Or gently spin the head in tiny circles.
The goal is to stay here 10-15 breaths (or up to 5 minutes) so that you can relax your facial muscles a little at a time. When you come up, use and inhale and tuck the tailbone. Keep the chin to the chest and slowly stack each vertebra one on top of the other until you're standing again. Then roll the shoulders upto your ears, down, and back toward the center of the spine. Your heart is open. Close your eyes and reflect on your experience.
Let me know if you want to try some more. I'll be glad to help.
