OBJETIVO: Analisar a intensidade da dor em indivíduos com disfunção temporomandibular (DTM) tratados com dez sessões de estimulação elétrica nervosa transcutânea (TENS) ou estimulação elétrica de Alta Voltagem (EEAV). MÉTODOS: Foram selecionadas 24 mulheres (22,98±1,86 anos) com diagnóstico de DTM, segundo o Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), sendo 60% com diagnóstico de DTM do grupo Ia e 40% Ia e IIa. As voluntárias foram divididas em dois grupos denominados grupo TENS (GT) e Grupo Alta Voltagem (GAV). Em ambos os grupos as voluntárias receberam dez aplicações da TENS (10Hz modulada em 50%, 200 µs e intensidade no limiar motor) ou da EEAV (10Hz, pulsos gêmeos com 20µs cada e intervalo 100µs interpulsos gêmeos, 100Volts e pólo positivo) duas vezes por semana por 30 minutos. Para mensurar a intensidade da dor, foi utilizada a escala visual analógica (EVA). Para análise estatística, utilizou-se teste t de Student e análise de regressão linear simples. RESULTADOS: Comparando-se as condições pré e pós TENS observa-se uma redução na intensidade da dor (p<0,05) na maioria das sessões, exceto na sexta, sétima e oitava, enquanto a EEAV reduziu a intensidade da dor (p<0,05) em todas as sessões. Avaliando-se os valores pré-aplicação, os dois recursos diminuíram a intensidade de dor de forma uniforme ao longo das dez sessões (p<0,05). CONCLUSÕES: A TENS e a EEAV promoveram redução da intensidade da dor em mulheres com DTM, sendo a EEAV mais um recurso indicado para o tratamento desses pacientes.

OBJECTIVE: To analyze pain intensity in individuals with temporomandibular disorder (TMD) who were treated with ten sessions of transcutaneous electrical nerve stimulation (TENS) or high voltage electrical stimulation (HVES). METHODS: Twenty-four women (22.98±1.86 years old) with a diagnosis of TMD in accordance with the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were selected. 60% of the subjects had a diagnosis of TMD classified as group Ia and 40% as Ia and IIa. They were divided into two groups named the TENS group (TG) and the high voltage group (HVG). Each individual received ten applications of either TENS (10Hz, modulated at 50%, 200µs and motor threshold intensity) or HVES (10Hz, twin pulses of 20µs each at intervals of 100µs between the twin pulses, 100volts and positive pole) twice a week for 30 minutes. To measure the pain intensity, a visual analog scale (VAS) was used. Statistical analyses were performed using Student's t test and simple linear regression. RESULTS: Comparison of the pre and post-TENS conditions showed diminished pain intensity (p<0.05) at most sessions except for sessions 6, 7 and 8. In contrast, HVES reduced the pain intensity at all sessions (p<0.05). Evaluation of the pre-application values showed that both treatments decreased the pain intensity uniformly over the ten sessions (p<0.05). CONCLUSIONS: TENS and HVES both promoted reductions in pain intensity in women with TMD. HVES is a therapeutic resource recommended for such patients.

Healthy individuals were examined in terms of the pattern of activity of the masseter and temporal muscles in their anterior portion of both right and left sides, respectively, with the maximum bite force. The study consisted in seventeen adult volunteers with no sign of apparent temporomandibular dysfunction, of both genders, connected to the School of Dentistry of Piracicaba, with average age of 25 years old. The electromyography data were obtained, bilaterally, of the masseter, anterior portion of temporal and suprahyoid muscles in the postural and isometric positions. Were utilized surface passive electrodes for kids of Ag/AgCl, of circular format and dischargeable of Meditrace® Kendall-LTP, model Chicopee MA01, attached to a pre-amplifier with gain of 20 times forming a differential circuit. The records of the electrical signs were captured by the equipment EMG-8OOC of EMG System of Brazil Ltd. of eight channels, with frequency of 2 KHz and 16 bits of resolution, digital filter with band pass of 20 to 500Hz. It was utilized also a pressurized transductor which consists of a pressurized rubber tube connected to a sensor element (MPX 5700) to obtain the maximum bite force. The statistic tests used were linear correlation, test t in pair and analysis of variance. Probability of p<0, 05 were significant considered statistically. The results showed a certain degree of muscular asymmetry for the masseter and anterior portion of temporal muscles that depended on the task performed or contraction level. The index of asymmetry was lower in the postural position than in the maximum bite force.

La actividad de los músculos masetero y de la porción anterior temporal de ambos lados, derecho e izquierdo, respectivamente, durante la fuerza máxima de mordedura fue estudiada en voluntarios sanos. El estudio incluyó a 17 voluntarios adultos de ambos sexos, edad promedia de 25 años, que no evidenciaban ningún indicio de disfunción temporomandibular y eran relacionados con la Facultad de Odontología de Piracicaba. Se registraron los datos electromiográficos en ambos lados de la cara del masetero y de la porción anterior de los músculos temporal y suprahioideo en las posiciones postural e isométrica. Se utilizaron electrodos de superficie pasivos para niños, de Ag/AgCl, con forma circular y descargables de Meditrace® Kendall-LTP, modelo Chicopee MA01. Éstos se conectaron a un preamplificador con una ganancia de 20x que formaba un circuito de diferenciales. Se captaron los registros de las señales eléctricas utilizando un equipo EMG-8OOC de EMG System of Brazil, Ltd., de ocho canales, a una frecuencia de 2 KHz con 16 bitios de resolución y un filtro digital con un paso de banda de 20 a 500 Hz. Se utilizó también un transductor de presión que consistía en un tubo de goma con un sensor de presión (MPX 5700)* (Motorola SPS, Austin, TX, EE.UU.) para registrar la fuerza máxima de mordedura. El análisis estadístico incluyó la correlación lineal, la prueba t emparejada y el análisis de la varianza. Se consideró estadísticamente significativa una probabilidad de p<0,05. Los resultados pusieron en evidencia cierto grado de asimetría muscular para el masetero y la porción anterior del músculo temporal que variaba en relación con la tarea realizada y la intensidad de la contracción. El índice de asimetría fue menor en la posición postural que en la de fuerza máxima de mordedura.

The purpose of the present study was to examine the relationship between the electromyographic (EMG) activity and heart rate (HR) responses induced by isometric exercise performed by knee extension (KE) and flexion (KF) in men. Fifteen healthy male subjects, 21 ± 1.3 years (mean ± SD), were submitted to KE and KF isometric exercise tests at 100% of maximal voluntary contraction (MVC). The exercises were performed with one leg (right or left) and with two legs simultaneously, for 10 s in the sitting position with the hip and knee flexed at 90o. EMG activity (root mean square values) and HR (beats/min) were recorded simultaneously both at rest and throughout the sustained contraction. The HR responses to isometric exercise in KE and KF were similar when performed with one and two legs. However, the HR increase was always significantly higher in KE than KF (P<0.05), whereas the EMG activity was higher in KE than in KF (P<0.05), regardless of the muscle mass (one or two legs) involved in the effort. The correlation coefficients between HR response and the EMG activity during KE (r = 0.33, P>0.05) and KF (r = 0.15, P>0.05) contractions were not significant. These results suggest that the predominant mechanism responsible for the larger increase in HR response to KE as compared to KF in our study could be dependent on qualitative and quantitative differences in the fiber type composition found in each muscle group. This mechanism seems to demand a higher activation of motor units with a corresponding increase in central command to the cardiovascular centers that modulate HR control.