Acupuncture Effect on Pain, Mouth Opening Limitation and on the Energy Meridians in Patients with Temporomandibular Dysfunction: A Randomized Controlled Trial

Temporomandibular disorders (TMD), recognized as the most common conditions of chronic orofacial pain, have a multifactorial etiology. Acupuncture can help to relieve the pain and discomfort associated with these conditions, because it can rebalance the energy (Qi) circulating in the meridians. The aim of the study was to verify the effectiveness of acupuncture in treating the pain; mouth opening limitation, and energy circulating in the meridians of patients with TMD of muscular or mixed origin. This was a controlled, randomized, double-blind clinical trial conducted at the Piracicaba Dental School (FOP/Unicamp), in Piracicaba SP, Brazil. The Treatment Group received acupuncture with real penetration of the needle, and the Placebo Group received a sham treatment without needle penetration. The acupoints used were: ST6, ST7, SI18, GV20, GB20, BL10, and LI4, during treatment performed for four weekly sessions. The TMD and mouth opening were evaluated according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC). The measurements of the energy at the meridians were performed by the Ryodoraku method, before and after acupuncture in all of the sessions in both groups. The results showed no decrease in pain in the Treatment Group when compared with the Placebo Group (p = 0.2261). There was no increase in the oral opening limit in the Treatment Group compared with the Placebo Group (p > 0.05). Regarding the energy levels, after acupuncture, there was a decrease in Yang energy in all sessions (p < 0.05), in both groups, however, only real acupuncture was effective in maintaining the Yin energy average throughout the four sessions, with significant difference between groups (p = 0.0198). In conclusion, volunteers with TMD presented a pattern of energy deficiency and the most prevalent imbalance patterns identified were in the meridians coupled to the kidney and bladder, and in the Shao Yin (heart/kidney) and Shao Yang (triple energizer/gall bladder) energetic planes. The acupuncture points used were equally effective in reducing pain in both groups; increasing the unassisted mouth opening limitation without pain in the Treatment Group, and were also effective in preserving the Yin energy in the Treatment Group. The Yang energy decreased equally in both groups.