>- isn't wise to use the zapper on the face
Only the positive electrode should touch anything but the hand. The positive electrode may be placed on the lower jaw or the upper jaw provided it is below the cheekbone without significant problems. If a sensation is noted in one of the teeth, it may be a indication of decay or abcess.
This does not mean that a problem will never occur, but from the data reported back to us, problems rarely occur from placing electrodes in this area.