Sometimes a sharp pain like rapid pin pricks is felt at the upper chin. The pin prick feels like it comes from the outside, not from the inside.
In my own experience, it was a reaction to general nervousness. It felt similar to the occasional sharp “pin pricks” on the heels which can be described as a “pins and needles” feeling occuring at a very small “point”.
In Chinese acupuncture, there is an acupuncture point (xue) right in the middle of the upper chin. It is a point on the meridian known as the “ren mai” that runs from the top of the head down the center front of the body. The sharp pain on the upper chin seems to occur at that exact spot. Thus, according to the Chinese theory of medicine in general and the Chinese theory of the “ren mai” in particular, the sharp pain at that spot on the upper chin indicates a blockage of energy that is supposed to run smoothly up and down the center front of the body. In the Chinese theory of acupuncture, “tong` ze” bu tong” and “tong ze” bu tong`”, i.e., “if it hurts, then it (internal energy) is blocked,” and “if it (internal energy) is not blocked, it will not hurt.” Since the sharp pain occurs at that exact point, it indicates that the energy that runs from the top of the head down the front of the body is blocked at that point.