Aim: Short-term pain reduction from acupuncture in chronic myofascial pain subjects was evaluated using an 11-point (0 to 10) numeric rating scale, visual analog scale (VAS), and pain rating of mechanical pressure on the masseter muscle.
Methods: A single-blind, randomized, controlled, clinical trial with an independent observer was performed. Fifteen chronic myofascial pain subjects over the age of 18 were randomly assigned into groups: nine subjects received real acupuncture; six subjects received sham acupuncture. Each subject clenched his/her teeth for 2 minutes. Acupuncture or sham acupuncture was administered at the Hegu Large Intestine 4 acupoint. Sham acupuncture was conducted by lightly pricking the skin with a shortened, blunted acupuncture needle through a foam pad, without penetrating the skin. The foam pad visually conceals the needle's point of the entry, so that the subject cannot discern which technique is being used. The subjects rated their general pain on a numeric rating scale. A mechanical pain stimulus was applied with an algometer and the subject rated his/her pain on a VAS. Statistical analysis was performed using the repeated measures anova, paired t-tests, and Fisher's exact test as appropriate.
Results: There was a statistically significant difference in pain tolerance with acupuncture (P = 0.027). There was statistically significant reduction in face pain (P = 0.003), neck pain (P = 0.011), and headache (P = 0.015) with perception of real acupuncture.
Conclusion: Pain tolerance in the masticatory muscles increased significantly more with acupuncture than sham acupuncture.