Many people struggle with TMJ pain or temporomandibular joint pain. This can include pain in the jaw, inability to fully open or close your mouth, ear-aches, headaches, grinding teeth, and even locking of the jaw. What causes it? Reasons can include deformity or old injuries of the jaw, injury, dental problems, or most commonly, stress. A formal study foundHEREcited back in 2010 showed that acupuncture at once per week for 8 weeks significantly reduced pain for 89% of the patients.