Yes. Temporomandibular joint dysfunction syndrome (TMJ) can cause muscular spasm type pain which can radiate and/or extend to the neck, shoulders and upper back.
Absolutely. Tmj is one aspect of a general group of craniomandibular disorders. Postural changes that can influence each other from the top of your head to the bottom of your feet. If your posture is not centered, the torsional changes cause nerves that go to your shoulder and arms to be "pinched.". One goal of its treatment, is to align the head and jaw. That often relieves these types of symptoms.