An investigation of the change in facial pain threshold after auricular acupuncture in healthy volunteers: a pilot study

Abstract

Auricular Acupuncture (AA) is both a diagnostic method and a treatment used to relieve pain and alleviate addictions. The effects and biological mechanisms of AA on the human body have been increasingly observed in clinical and experimental studies based on the gate control theory and the endogenous opioids theory. The purpose of this study was to investigate changes in facial pain thresholds among healthy volunteers after applying AA to acupoints on both auricles. This was a pilot study with a crossover randomized controlled trial design. 66 healthy volunteers with normal hemodynamic indexes were randomly assigned to one of two groups to receive AA treatment at the Shenmen point, Sympathetic point, Adrenal gland point, Jaw point, and Tooth point of either the left or right auricle (phase 1). 7 days later, participants received sham acupuncture at the same points (phase 2). In phase 1, the results showed that AA at these points in either auricle increased the pain threshold of the facial skin statistically significantly (p<0.05). No statistically significant difference was detected in the sham acupuncture phase. This suggests that AA can be used as a non-pharmacological adjunct to facial pain relief.