Randomized Clinical Trial of Acupuncture for Myofascial Pain of the Jaw Muscles

Aims: To evaluate the effectiveness of acupuncture in treating symptoms associated with myofascial pain of the jaw muscles. Methods: Twenty-eight subjects over the age of 18 and diagnosed with chronic myofascial pain of the jaw muscles were randomized to receive real (n = 16) or sham (n = 12) acupuncture. Prior to treatment, each subject clenched his or her teeth for 2 minutes. Acupuncture or sham acupuncture was then administered at the Hegu large intestine 4 (LI4) acupoint for 15 minutes. Real acupuncture was given by penetrating the needle through a sticky foam pad at the acupoint. Sham acupuncture was conducted by pricking the skin, without penetration, with a shortened, blunted acupuncture needle through a foam pad placed away from the acupoint. General head and neck pain ratings were obtained before and after treatment on a numerical rating scale. A mechanical pain stimulus on the masseter muscle was given before and after treatment and rated on a visual analog scale to measure pain tolerance level. Paired t tests were performed to detect significant changes in pain levels. Results: Subjects receiving real acupuncture experienced a significant reduction in jaw pain (P = .04), jaw/face tightness (P = .04), and neck pain (P = .04), and a significant increase in pain tolerance of the masseter muscle (P = .001). Subjects were not able to determine whether they received real or sham acupuncture (P = .69). No significant pain reductions were observed in the sham acupuncture group. Conclusion: A single acupuncture session using one acupoint at Hegu large intestine 4 significantly reduced most myofascial pain endpoints when compared to sham acupuncture.

acupuncture; analgesia; Hegu large intestine 4; myofascial pain; placebo, sham

1. Simons DG, Travell JG, Simons PT. Travell and Simons’ Myofascial Pain and Dysfunction. The Trigger Point Manual, vol 1. Upper Half of Body, ed 2. Baltimore: Williams and Wilkins, 1999.

2. Travell JG, Simons DG: Myofascial Pain and Dysfunction: The Trigger Point Manual, vol 1. Baltimore: Williams and Wilkins, 1983.

3. National Institutes of Health Consensus Panel. Acupuncture: National Institutes of Health Consensus Development Conference Statement: http://consensus.nih.gov/1997/1997acupuncture107html.htm. Accessed June 22, 2007.

4. Lytle CD. History of the Food and Drug Administration’s regulation of acupuncture devices. J Altern Complement Med 1996;2:253–256.

5. NIH Consensus Statement. Acupuncture. JAMA 1998; 280:1518–1524.

6. Audette JF, Blinder RA. Acupuncture in the management of myofascial pain and headache. Curr Pain Headache Rep 2003;7:395–401.

7. Harris RE, Clauw DJ. The use of complementary medical therapies in the management of myofascial pain disorders. Curr Pain Headache Rep 2002;6:370–374.

8. Edelist G, Gross AE, Langer F. Treatment of low back pain with acupuncture. Can J Anaesth Soc 1976;23: 303–306.

9. Brandwein A, Corcos J. Extraction of incisors under acupuncture anesthesia: A standardized method. Am J Acup 1975;3:352–354.

10. Goddard G, Karibe H, McNeil C, Villafuerte E. Acupuncture and sham acupuncture reduce muscle pain in myofascial pain patients. J Orofac Pain 2002;16:71–76.

11. Kerr NW. Acupuncture for therapy and analgesia. A possible application in dental surgery. Br Dent J 1973;134: 201–204.

12. Lao L, Bergman S, Hamilton GR, Langenberg P, Berman

B. Evaluation of acupuncture for pain control after oral surgery: A placebo-controlled trial. Arch Otolaryngol Head Neck Surg 1999;125:567–572.

13. Lee MHM, Teng P, Zaretzky H H, Rubin M. Acupuncture anesthesia in dentistry. A clinical investigation. N Y State D J 1973;39:299–301.

14. Mann F. Acupuncture analgesia in dentistry. Lancet 1972;1:898–899.

15. Rosted P. The use of acupuncture in dentistry: A review. Compl Med Int 1996;3:18–21.

16. Silva SA. Acupuncture for the relief of pain of facial and dental origin. Anesth Prog 1989;36:244–245.

17. Tany M, Matsudaira K, Sawatsugawa S, Manaka Y. Acupuncture analgesia and its application in dental practice. Am J Acup 1974;2:287–295.

18. Shen J. Research on the neurophysiological mechanisms of acupuncture: Review of selected studies and methodological issues. J Altern Complement Med 2001;7(suppl 1): S121–S127.

19. Biella G, Sotgiu ML, Pellegata G, Paulesu E, Castiglioni I, Fazio F. Acupuncture produces central activations in pain regions. Neuroimage 2001;14:60–66.

20. Bowsher D. Mechanisms of acupuncture. In: Filshie J, White A (eds). Medical Acupuncture: A Western Scientific Approach. London: Churchill Livingston, 1998:69–82.

21. Han JS, Neurochemical basis of acupuncture. Annu Rev Pharmacol Toxicol 1982;22:193–220.

22. Hess J, Magelvang B, Simonsen H. Acupuncture versus metoprolol in migraine prophylaxis: A randomized trial of trigger point inactivation. J Intern Med 1994;235:451–456.

23. Ekblom A, Hansson P, Thomsson M, Thomas M. Increased post operative pain and consumption of analgesics following acupuncture. Pain 1991;44:241–247.

24. Grabow L. Controlled study of the analgesic effectivity of acupuncture. Arzneimittelforschung 1994;44:554–558.

25. Kong J, Ma L, Gollub RL, et al. A pilot study of functional magnetic resonance imaging of the brain during manual and electroacupuncture stimulation of acupuncture point (LI-4 Hegu) in normal subjects reveals differential brain activation between methods. J Altern Complement Med 2002;8:411–419.

26. Kaptchuk TJ. Acupuncture: Theory, efficacy, and practice. Ann Intern Med 2002;137:702–703.

27. Shen Y, Goddard G. Short term effects of acupuncture on myofascial pain patients after clenching. Pain Pract 2007;7:256–264.

28. Okeson JP. Management of Temporomandibular Disorders and Occlusion, ed 5. St. Louis: Mosby, 2003: 339–342.

29. Stacher G, Wancura I, Bauer P, Lahoda R, Schulze D. Effect of acupuncture on pain threshold and pain tolerance determined by electrical stimulation of the skin: A controlled study. Am J Chin Med 1975;3:143–149.

30. Hui KK, Liu J, Makris N, et al. Acupuncture modulates the limbic system and subcortical gray structures of the human brain: Evidence from fMRI studies in normal subjects. Hum Brain Mapp 2000;9:13–25.

31. Tillu A, Roberts C, Tillu S. Unilateral versus bilateral acupuncture on knee function in advanced osteoarthritis of the knee: A prospective randomised trial. Acupunct Med 2001;19:15–18.

32. Audette JF, Wang F, Smith H. Bilateral activation of motor unit potentials with unilateral needle stimulation of active moyfascial trigger points. Am J Phys Med Rehabil 2004;83:368–374.

33. Goddard G, Shen Y, Steele B. A controlled trial of placebo vs real acupuncture. Pain 2005;4:237–242.

34. Streitberger K, Kleinhenz J. Introducing a placebo needle into acupuncture research. Lancet 1998;352:364–365.

35. Farrar JT, Young JP Jr, LaMoreaux L, Werth JL, Poole RM. Clinical importance of changes in chronic pain intensity measured on an 11-point numerical pain rating scale. Pain 2001;94:149–158.

36. Kam E, Eslick G, Campbell I. An audit of the effectiveness of acupuncture on musculoskeletal pain in primary health care. Acupunct Med 2002;20:35–38.

37. Park J, White A, Stevinson C, Ernst E, James M. Validating a new non-penetrating sham acupuncture device: Two randomised controlled trials. Acupunct Med 2002;20:168–174.

38. Smith P, Mosscrop D, Davies S, Sloan P, Al-Ani Z. The efficacy of acupuncture in the treatment of temporomandibular joint myofascial pain: A randomised controlled trial. J Dent 2007;35:259–267.

39. Michelotti A, Farella M, Stellato A, Martina R, De Laat

A. Tactile and pain threholds in patients with myofascial pain of the jaw muscles: A case-control study. J Orofac Pain 2008;22:139–145.

40. Karst M, Rollnik JD, Fink M, Reinhard M, Piepenbrock

S. Pressure pain threshold and needle acupuncture in chronic tension-type headache: A double-blind placebo- controlled study. Pain 2000;88:199–203.

41. McMillan AS, Nolan A, Kelly PJ. The efficacy of dry needling and procaine in the treatment of myofascial pain in the jaw muscles. J Orofac Pain 1997;11:307–314.

42. Tough EA, White AR, Cummings M, Richards SH, Campbell JL. Acupuncture and dry needling in the management of myofascial trigger point pain: A systematic review and meta-analysis of randomized controlled trials. Eur J Pain 2009;13:3–10.