Am J Chin Med. 1986 ; 14(1-2): 68-72.

Electroacupuncture increases ipsilaterally tooth pain threshold in man.

Yukizaki H, Nakajima S, Nakashima K, Yamada Y, Sato T.

The effect of electroacupuncture stimulation applied to a unilateral Ho-ku point on the human tooth pain thresholds was studied by electrically stimulating bilateral canines. In six of ten subjects tested, the tooth pain threshold was elevated ipsilaterally but was unchanged contralaterally during and after the electroacupuncture. In the remaining four, neither the ipsilateral nor the contralateral canine showed any change in the pain threshold by the electroacupuncture. The ipsilateral increase of the tooth pain threshold may be explained by a mechanism by which electroacupuncture stimulation of one Ho-ku point causes various pain suppression centers to release ipsilaterally endogenous opioids.