The jaw-pelvis connection is real! When I ask my TMD (temporomandibular disorder) clients if they also have pelvic alignment issues, a lot of them say yes.
If your pelvis is out of alignment, quite often, so is your jaw.
Here’s how that relationship works: The back of your pelvis includes the base of your spine, the triangle-shaped sacrum. Your jaw — mandible — is near the upper end of your spine, and it has a special relationship with the uppermost two vertebrae at the top of your neck, C1 and C2.
Because the opening/closing motion of the jaw is both hinging and gliding (open your mouth slowly and you can feel it hinge, then glide forward as you open wider), the axis of rotation is not in the actual jaw joints but is located between these two vertebrae, according to Guzay’s theorem (Guzay was an engineer interested in neurology).
The images below show the TMJ and the axis of rotation when with jaw closed (left) and open (right). The upper cross-hairs show the TMJ, and the lower cross-hairs show the actual axis of rotation for jaw opening and closing.
(Image source: The Heart of Listening Volume 2 by Hugh Milne)
When your pelvis is misaligned, it affects these vertebrae, impacting neck and head posture and neurological well-being. (This is why nearly everyone I treat for TMJ issues also has neck issues, which I treat too.)
How can the pelvis affect the jaw? There is a tough, inelastic membrane surrounding your spinal cord that connects your sacrum with your cranium. The dura mater lines the inside of your neurocranium, includes membranes between the two hemispheres and between the cerebrum and cerebellum of your brain, and forms the dural tube containing cerebrospinal fluid that surrounds the spinal cord, all the way down to your sacrum.
The dural tube is attached to the C1, C2, and C3 vertebrae and then descends unattached all the way down the spine to the sacrum, where it attaches to bone again. The dura mater continues to the tip of the coccyx.
When the sacrum is not aligned with the other pelvic bones — in other words, when you have sacroiliac joint problems, it torques the inelastic dura mater all the way up to the upper neck vertebrae that affect the movement of the TMJs.
This torquing of the dura mater may be seen in abnormal spinal curves, pelvic rotation or tilt, head tilt, and cranial bone misalignment, which can affect your fluids, hormones, and central nervous system.
Here’s a little exercise: put your fingertips in front of your ears and open and close your jaw slowly a few times. Notice if your left and right TMJs move differently. You may notice one side opens first and/or protrudes further out or forward than the other.
This shows your TMJs are unbalanced. Because the mandible is one bone with two joints, even if one joint is out of balance, the other joint is affected, though you may not feel symptoms in both.
It seems likely to me that this contributes to nine times more women than men suffering from TMJ disorders, since women have more pelvic floor issues than men. (Also more stress.)
