Comparative effects of acupuncture in Japan and the United States on dental pain perception.

The effect of low frequency electrical acupunctural stimulation on the perception of induced dental pain were compared in two cultural settings. Twenty Japanese and 20 American subjects (consisting of 10 Caucasians and 10 second or third generation Japanese) were tested in two functionally identical laboratories, one at Tottori University in Yonago, Japan and the other at the University of Washington. Each subject underwent a control and an acupuncture session on separate days wtih subjects counterbalanced for carry-over order effects. Sensory decision theory (SDT) analysis demonstrated a significant reduction in perceptual capability and an increased bias against reporting stimuli as painful following the acupuncture as treatment which was performed bilaterally at traditional facial points. No significant differences between groups in alteration of perceptual capability, bias or pain threshold were demonstrated, indicating that the cultural and racial differences studied did not influence responses to acupuncture in a laboratory setting.