One of the longest nerves in the body is known as the vagus nerve (VN). The VN is the 10th pair of cranial nerves that originates at the brain stem in the medulla oblongata. This nerve is part of the parasympathetic nervous system, which is a part of the ANS. Research suggests ear acupuncture can activate the VN.
Stay Within Your Scope of Practice
I practice acupuncture in New Jersey. According to the our state laws, "Acupuncture is the stimulation of points by the insertion of needles (plus adjunctive therapies)." "Physical Therapy is intervention by means of manual therapy techniques (plus mechanical modalities)."
PT's are not licensed to insert needles. Those that claim they are doing dry needling are not using "PT needles," they are using acupuncture needles.
My recollection is that the term "dry needling" resulted from the abandonment of fluid filled hypodermic needles. Dr. Janet Travell, a cardiologist, noted that the heart pain that some of her patients were experiencing was the result of tight pectoral muscles (trigger points).
Injecting lidocaine via hypodermic needles treated the pain. It was later discovered that using the needle without pain medication was just as effective. This was called dry needling.

Dr. Mark Seem, of the Tri-State College of Acupuncture, conferred with Dr. Travell about using acupuncture needles (much thinner) to treat trigger points. This was very effective.
Those of us who graduated from his school had many, many hours of practicing this style, plus the Clean Needle Technique procedures.
It in an insult to our knowledge and experience that anyone with much less hours of instruction can be allowed to use acupuncture needles. This treatment should only be allowed within the scope of practice of acupuncture.
Virginia E. Mills, MS, LAc, CC
New Jersey