The short-term effects of acupuncture on myofascial pain patients after clenching.
OBJECTIVE
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.


CONCLUSIONS
Pain tolerance in the masticatory muscles increased significantly more with acupuncture than sham acupuncture.
Shen
Yoshi F
YF
Center for Orofacial Pain, Department of Oral and Maxillofacial Surgery, University of California San Francisco, San Francisco, California 94143-0768, USA. yosh9898@yahoo.com
Goddard
Greg
G
D015667:Acupuncture Analgesia / Q000379:methods; D000328:Adult; D005156:Facial Neuralgia / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000502:physiology; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D017288:Pain Threshold / Q000502:physiology; D010812:Physical Stimulation / Q000379:methods; D016037:Single-Blind Method; D013706:Temporomandibular Joint Dysfunction Syndrome / Q000503:physiopathology / Q000628:therapy; D013997:Time Factors