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


METHODS
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.
Rancan
Sandra Valéria
SV
Ribeirão Preto Dental School, São Paulo University, São Paulo, Brazil.
Bataglion
César
C
Bataglion
Solange Aparecida
SA
Bechara
Odinê Maria Rêgo
OM
Semprini
Marisa
M
Siéssere
Selma
S
Sousa
João Paulo Machado de
JP
Crippa
José Alexandre de Souza
JA
Hallak
Jaime Eduardo Cecilio
JE
Regalo
Simone Cecilio Hallak
SC
D000328:Adult; D001732:Bite Force; D001938:Brazil; D004576:Electromyography; D006801:Humans; D008410:Masticatory Muscles / Q000503:physiopathology*; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D059408:Pain Management; D013704:Temporomandibular Joint / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000628:therapy*