Emg analysis after laser acupuncture in patients with temporomandibular dysfunction (TMD). Implications for practice.

The aim of this study was to analyze the effect of low level laser applied to acupuncture points of patients diagnosed with temporomandibular dysfunction (TMD). Ten patients aged between 20 and 50 years were clinically examined with regard to pain and dysfunction of the masticatory system. They received laser applications (GaAlAs diode laser, 780 nm wavelength; 70 mW power output, 35 j/cm(2)) in acupuncture specific points (Ig4, C3, E6, E7) once a week, for ten sessions. The range of jaw movement was registered after each session and visual analogue scale (VAS) was applied. Results were analyzed (SPSS-15.0-Chicago) during the comparison, before and after treatment. Statistical tests showed significant improvements (p < 0.01) in painful symptoms and electromyographic activities of masseter muscles in maximal habitual occlusion after laser applications but no significant improvements (p = 0.05) in measurements of mandibular movements. The laser therapy in specific acupuncture points promoted improvement of symptoms and it may be used as complementary therapy for TMD.

Acupuncture and temporomandibular disorders: a 3-month follow-up EMG study.

OBJECTIVES: The purpose of this study was to investigate the levels of electromyographic (EMG) activation and maximal molar bite force before and after a 3-month acupuncture therapy in individuals with temporomandibular disorder (Helkimo Index) from a pool of subjects attending the Special Care Course of the Ribeirão Preto Dental School, São Paulo University, Brazil. DESIGN: All 17 patients, aged between 37 and 50 years (44.2 +/- 4.84 years), with an average weight of 71 +/- 9.45 kg and height of 1.64 +/- 0.07 m, were clinically examined with regard to pain and dysfunctions of the masticatory system. The temporomandibular acupuncture points of needling were IG4, E6, E7, B2, VB14, VB20, ID18, ID19, F3, E36, VB34, E44, R3, and HN3. EMG measures were acquired before and after the treatment using a MyoSystem-BR1 electromyographer. The data collected at rest, protrusion, left and right laterality, and clenching were normalized by maximum voluntary contraction. Maximal bite force in right and left molar regions were registered using a dynamometer with a capacity of up to 1000 N, adapted for oral conditions. The highest value out of three recordings was considered to be the individual's maximal bite force. The results were statistically analyzed using the paired t test (SPSS version 15.0) during the comparison before and after treatment. RESULTS: We found decreased EMG activity at rest, protrusion, left and right laterality, and clenching; as well as increased values of maximal bite force after acupuncture treatment. CONCLUSIONS: Acupuncture promoted alterations in the EMG activity of masticatory muscles, increased maximal molar bite force, and led to remission of the subjects' painful symptomatology.