Masticatory function according to body mass index: part II: electromyographic analysis / Función masticatoria según índice de masa corporal: parte II: análisis electromiográfico

Introduction: The objective of this study was to explore the electrical activity of the superficial muscles of mastication required to exert unilateral maximum bite force in subjects with different body mass index. Material and Methods: A cross-sectional observational study was conducted with a sample of 21 participants with an average age of 22.9 ± 3.5 years who were classified according to their body mass index, forming three study groups: normal weight (18.5-24.9), overweight (25-29.9) and obesity (≥30), with seven participants each. Through surface electromyography, the superficial muscles of mastication during right and left maximum bite force were evaluated. Results: No statistically significant differences in the maximum bite force were observed between the study groups. The data obtained from the electromyographic analysis of the superficial muscles of mastication demonstrate a trend indicating that subjects with a normal body mass index similarly activate the muscles on each side when performing a maximum bite force on a particular side, while overweight or obese subjects demonstrated significantly greater activation of the temporalis muscle associated with the side where the maximal bite force is performed. Conclusion: Our findings suggest that the maximum bite force is not influenced by body mass index and that during the performance of a maximum bite force subjects with increased body mass index present a greater activation of the temporalis muscle associated with the side where the maximum bite force was performed.

Introducción: El objetivo de este estudio fue explorar la actividad eléctrica de los músculos superficiales de la masticación, necesarios para ejercer la máxima fuerza de mordida unilateral, en sujetos con diferente índice de masa corporal. Material y Métodos: Se realizó un estudio observacional de corte transversal con una muestra de 21 participantes con una edad promedio de 22.9 ± 3.5 años, quienes fueron clasificados de acuerdo a su índice de masa corporal, formando tres grupos de estudio: peso normal (18,5-24,9), sobrepeso (25,0-29,9) y obesidad (≥30.0), con siete participantes cada uno. La electromiografía de superficie evaluó los músculos superficiales de la masticación durante la fuerza de mordida máxima derecha e izquierda. Resultados: No se observaron diferencias estadísticamente significativas en la fuerza de mordida máxima entre los grupos de estudio. Los datos obtenidos del análisis electromiográfico de los músculos superficiales de la masticación demuestran una tendencia que indica que los sujetos con un índice de masa corporal normal activan de manera similar los músculos de cada lado cuando ejercen la fuerza de mordida máxima en un lado en particular. mientras que los sujetos con sobrepeso u obesos demostraron una activación significativamente mayor del músculo temporal asociado con el lado donde se realiza la fuerza máxima de mordida. Conclusión: Nuestros hallazgos sugieren que la fuerza de mordida máxima no está influenciada por el índice de masa corporal y que durante la realización de una fuerza de mordida máxima los sujetos con índice de masa corporal aumentado presentan una mayor activación del músculo temporal asociado al lado donde se realizó la fuerza de mordida máxima.

Dimensión vertical de la cara en adultos con diferentes relaciones oclusales / Vertical dimension of face in adults with different Angle class

RESUMEN: Se ha postulado que la posición postural mandibular (PPM) no presentaría la menor actividad electromiográfica (EMG) de los músculos masetero y temporal, y que esta menor actividad se encontraría en una apertura mayor. El objetivo de este estudio fue analizar la PPM en pacientes con diferentes relaciones oclusales y según tipo de método de posicionamiento, relacionándolo con la actividad EMG de los músculos Masetero y Temporal, además del registro de la actividad EMG en diferentes aperturas orales. Se analizó una muestra de 25 adultos de 18 a 28 años. Estos fueron clasificados según su sexo y clasificación de Angle. Se realizaron simultáneamente registros de EMG de superficie -masetero y porción anterior del temporal- y de EMA -posición de la mandíbula respecto al maxilar obteniendo distancia y ángulo- en diferentes posiciones mandibulares: PPM-considerando método sin comando y de deglución- y apertura gradual hasta alcanzar la máxima apertura. Se realizó un análisis estadístico descriptivo. La menor PPM obtenida fue de 1,0 ± 0,6 mm en mujeres Clase III y utilizando la técnica sin comando; el mayor fue de 2,5 ± 0,2 mm en mujeres Clase II y utilizando la técnica de deglución. La apertura angular presentó menor variabilidad que las distancias lineales. La actividad de los músculos Maseteros derecho e izquierdo presentaron valores similares entre sí, al igual que en los rangos de apertura hasta 30 mm en hombres y mujeres y en las diferentes relaciones oclusales. La actividad de los Temporales para hombres y mujeres y en las diferentes relaciones oclusales mostraron variaciones importantes entre derecha e izquierda y en los diferentes grados de apertura. La técnica presentada permitió el estudio de la dimensión vertical y aperturas orales a través de EMA y EMG.

SUMMARY: It has been postulated that the mandibular postural position (MPP) could not present the lower electromyographic activity (EMG) of the Masseter and Temporal muscles, and that the lower activity could be found in a larger opening. The objective of this study was to analyze the PPM in patients with different occlusal relationships and according to the positioning method, relating it to the EMG activity of the Masseter and Temporal muscles, in addition to recording the EMG activity in different oral openings. A sample of 25 adults aged 18 to 28 years was analyzed. Participants were classified according to their sex and Angle classification. Simultaneous recordings of surface EMG -Masseter and anterior portion of the Temporal- and EMA -position of the Mandible with respect to the Maxilla obtaining distance and angle- were performed in different mandibular positions: PPM-considering the method "without command" and "swallowing"- and gradual opening until the maximum opening is reached. A descriptive statistical analysis was performed. The lowest PPM obtained was 1.0 ± 0.6 mm in Class III women and using the "without command" method; the largest was 2.5 ± 0.2 mm in Class II women and using the "swallowing" method. The angular opening presented less variability than the linear distances. The activity of the right and left masseter muscles presented similar values, as well as in the opening ranges up to 30 mm in men and women and in the different occlusal relationships. The activity of the Temporals for men and women and in the different occlusal relationships showed important variations between right and left and in the different degrees of opening. The presented technique allowed the study of the vertical dimension and oral openings through EMA and EMG.

Função mastigatória nos diferentes ciclos de vida: análise eletromiográfica / Chewing function in different life cycles: analysis with electromyography / Función masticatoria en diferentes ciclos de vida: análisis con electromiografía

Introdução: A mastigação tem uma importância significativa para o desenvolvimento das estruturas do Sistema Estomatognático (SE), sendo esta aperfeiçoada no decorrer da vida. A eletromiografia de superfície destaca-se como uma importante ferramenta de avaliação capaz de quantificar a atividade elétrica dos músculos mastigatórios, sendo uma forma de caracterizar o comportamento dessa função estomatognática. Observando a complexidade e importância da mastigação, torna-se importante conhecer melhor as modificações desta função no decorrer dos ciclos de vida. Objetivo: O objetivo do estudo foi realizar análise eletromiográfica dos músculos da mastigação em indivíduos sem queixas orofaciais representantes dos ciclos da infância, adolescência, fase adulta e senescência. Método: A amostra foi composta por 120 voluntários de ambos os sexos, distribuídos em quatro grupos de acordo com a faixa de idade. Os voluntários foram submetidos à avaliação da mastigação por meio da eletromiografia de superfície durante o repouso, contração voluntária máxima, mastigações unilaterais direita e esquerda e mastigação habitual; bem como a verificação da força de mordida entre os dentes incisivos centrais, molares do lado direito e molares do lado esquerdo. Realizou-se, ainda, a tomada de medidas antropométricas faciais das hemifaces direta e esquerda dos voluntários. Resultados: Os resultados apontaram comportamentos morfológicos e funcionais distintos entre os grupos estudados, bem como a influência da variável sexo nas respostas eletrofisiológicas da função mastigatória. Conclusão: foi verificado que o comportamento mastigatório variou segundo a idade e o sexo, apontando uma tendência de correlação entre os componetes anatômicos e funcionais envolvidos nessa função estomatognática.

Introduction: Chewing is of significant importance for the development of the structures of the Stomatognathic System (SE), which is improved throughout life. Surface electromyography stands out as an important assessment tool capable of quantifying the electrical activity of the masticatory muscles, being a way to characterize the behavior of this stomatognathic function. Observing the complexity and importance of chewing, it is important to better understand the changes in this function during the life cycles. Objective: The objective of the study was to perform an electromyographic analysis of the muscles of mastication in individuals without orofacial complaints representing the cycles of childhood, adolescence, adulthood and senescence. Method: The sample consisted of 120 volunteers of both sexes, distributed in four groups according to the age group. The volunteers underwent chewing assessment by means of surface electromyography during rest, maximum voluntary contraction, unilateral right and left chewing and habitual chewing; as well as the verification of the bite force between the central incisor teeth, molars on the right side and molars on the left side. Facial anthropometric measurements of the direct and left hemifaces of the volunteers were also taken. Results: The results showed distinct morphological and functional behaviors between the groups studied, as well as the influence of the gender variable on the electrophysiological responses of the masticatory function. Conclusion: it was found that the masticatory behavior varied according to age and sex, pointing to a trend of correlation between the anatomical and functional components involved in this stomatognathic function.

Introducción: La masticación es de gran importancia para el desarrollo de las estructuras del Sistema Estomatognático (SE), que se mejora a lo largo de la vida. La electromiografía de superficie se destaca como una importante herramienta de evaluación capaz de cuantificar la actividad eléctrica de los músculos masticatorios, siendo una forma de caracterizar el comportamiento de esta función estomatognática. Observando la complejidad de esta función, es importante conocer mejor los cambios de esta función durante los ciclos de vida. Objetivo: El objetivo del estudio fue realizar un análisis electromiográfico de los músculos de la masticación en individuos sin quejas orofaciales representando los ciclos de niñez, adolescencia, adultez y senescencia. Método: La muestra estuvo formada por 120 voluntarios de ambos sexos, distribuidos en cuatro grupos según el grupo de edad. Los voluntarios fueron sometidos a valoración masticatoria mediante electromiografía de superficie en reposo, máxima contracción voluntaria, masticación unilateral derecha e izquierda y masticación habitual; así como la verificación de la fuerza de mordida entre los incisivos centrales, molares del lado derecho y molares del lado izquierdo. También se tomaron medidas antropométricas faciales de los hemifaces directo e izquierdo de los voluntarios. Resultados: Los resultados mostraron distintos comportamientos morfológicos y funcionales entre los grupos estudiados, así como la influencia de la variable género en las respuestas electrofisiológicas de la función masticatoria. Conclusión: se encontró que el comportamiento masticatorio varió según la edad y el sexo, apuntando a una tendencia de correlación entre los componentes anatómicos y funcionales involucrados en esta función estomatognática.

Variação da atividade elétrica entre o repouso e a máxima contração voluntária dos músculos masseteres em homens adultos / Variation of electrical activity between rest and maximum voluntary contraction of masseter muscles in adult men / Variación de la actividad eléctrica entre el descanso y la contracción voluntaria máxima de los músculos maseteros en hombres adultos

Introdução: A eletromiografia de superfície (EMGs) é um exame objetivo, indolor, não invasivo e de fácil aplicação utilizado para avaliar as atividades elétricas de determinado músculo ou grupo muscular durante a máxima contração voluntária, repouso e dinâmica funcional. Objetivo: Comparar a variação do potencial elétrico dos músculos masseteres entre o repouso e máxima contração voluntária em indivíduos com faixas etárias diferentes. Método: A pesquisa foi aprovada em comitê de ética e executada na Clínica Escola do Departamento de Fonoaudiologia da Universidade Federal de Sergipe obedecendo aos rigores éticos e de biossegurança. A amostra foi composta por 26 adultos sem queixas orofaciais, sexo masculino e idade variando entre 26 e 42 anos, divididos em Grupo 1 e Grupo 2, os quais assinaram um termo de consentimento livre e esclarecido concordando com a participação na pesquisa. Os voluntários foram submetidos à avaliação eletromiográfica dos músculos masseteres durante o repouso e máxima contração voluntária. Resultados: Houve uma diminuição da atividade elétrica do masseter quando se comparou o G1 com o G2, porém não foi observada uma linearidade desse declínio ao analisar o universo estudado. Por isso, deve-se levar em consideração que o envelhecimento é um processo fisiológico particular de cada ser, sendo influenciado por múltiplos fatores intrínsecos e extrínsecos ao organismo. Observou-se, também, que no repouso nenhum indivíduo teve absolutamente 0 nos seus registros eletromiográficos, caracterizando um estado basal de atividade elétrica para garantia do tônus. Conclusão: Foi verificado que os voluntários com 30 anos ou mais apresentaram um declínio nos potenciais mioelétricos e, possivelmente, um déficit de força associado.

Introduction: Surface electromyography (EMGs) is an objective, painless, non-invasive and easily applied test used to assess the electrical activities of a particular muscle or muscle group during maximum voluntary contraction, rest and functional dynamics. Objective: Compare the variation in the electrical potential of the masseter muscles between rest and maximum voluntary contraction in individuals with different age groups. Method: The research was approved by the ethics committee and carried out at the Clínica Escola of the department of Speech, Language and Hearing Sciences at the Federal University of Sergipe, obeying ethical and biosafety rigors. The sample consisted of 26 adults without orofacial complaints, male with age from 26 to 42 years old, divided into Group 1 and Group 2, who signed a consent form agreeing to participate in the research. The volunteers underwent electromyographic evaluation of the masseter muscles during rest and maximum voluntary contraction. Results: There was a decrease in the electrical activity of the masseter when comparing G1 to G2; however, there was no linearity of this decline when analyzing the universe studied. Therefore, it must be taken into account that aging is a particular physiological process of each individual, being influenced by multiple factors, intrinsic and extrinsic to the organism. It was also observed at rest, no individual had absolutely 0 in their electromyographic records, characterizing a baseline state of electrical activity to guarantee tone. Conclusion: It was found that volunteers aged 30 years or more showed a decline in myoelectric potentials and possibly an associated strength deficit.

Introducción: Electromiografía de superficie (EMG) es una prueba objetiva, indolora, no invasiva y de fácil aplicación que se utiliza para evaluar actividades eléctricas de un músculo o grupo muscular en particular durante la contracción voluntaria máxima, el reposo y la dinámica funcional. Objetivo: Comparar la variación del potencial eléctrico de los maseteros entre reposo y contracción voluntaria máxima en individuos de diferentes grupos de edad. Método: La investigación fue aprobada por el comité de ética y realizada en la Clínica Escola del departamento de logopedia de la Universidad Federal de Sergipe obedeciendo rigores éticos y de bioseguridad. La muestra estuvo conformada por 26 adultos sin quejas orofaciales, varones y edades comprendidas entre 26 y 42 años dividido en Grupo 1 y Grupo 2, quienes firmaron formulario de consentimiento aceptando participar en la investigación. Los voluntarios se sometieron a evaluación electromiográfica de los músculos maseteros durante reposo y la máxima contracción voluntaria. Resultados: Hubo disminución en la actividad eléctrica del masetero cuando se comparó G1 con G2, sin embargo no hubo linealidad de esta disminución al analizar el universo estudiado. Por tanto, hay que tener en cuenta que el envejecimiento es proceso fisiológico particular de cada ser, siendo influenciado por múltiples factores intrínsecos y extrínsecos al organismo. También se observó que en reposo ningún individuo tenía absolutamente 0 en sus registros electromiográficos, caracterizando estado basal de actividad eléctrica para garantizar el tono. Conclusión: Se encontró que los voluntarios de 30 años o más mostraron una disminución en los potenciales mioeléctricos y posiblemente un déficit de fuerza asociado.

Relación entre Síntomas de Trastornos Témporomandibulares Auto-Reportados y el Movimiento Mandibular de Sujetos Adultos Jóvenes / Relationship Between Symptoms of Self-Reported Temporomandibular Disorders and Mandibular Movement of Young Adult Subjects

RESUMEN: Tanto la limitación del movimiento mandibular como el auto reporte de síntomas de trastornos témporomandibulares (TTM) son utilizados como elementos para el diagnóstico de pacientes en la clínica. Sin embargo, la relación entre la presencia de síntomas y el movimiento mandibular no está del todo clara. Por ello, el objetivo de este estudio fue relacionar la presencia de síntomas asociados a TTM con el movimiento mandibular en una muestra de sujetos adultos jóvenes y sanos. En este estudio exploratorio participaron 40 estudiantes de Odontología, médicamente sanos, con arco dentario maxilar y mandibular continuo y completo (hasta el primer molar). A cada uno se les solicitó responder un cuestionario de auto-reporte de síntomas asociados a TTM recomendado por la American Academy of Orofacial Pain (AAOP). También se realizó un registro y análisis de sus movimientos mandibulares utilizando articulografía electromagnética 3D, con el objetivo de correlacionar la presencia de síntomas con el rango y trayectoria de apertura, y el área comprendida en lo que se describe como polígono de Posselt en el plano frontal y sagital. No se encontraron diferencias significativas entre las respuestas a cada pregunta entre hombres y mujeres. De acuerdo a las respuestas y según Delcanho (1994), 12 participantes resultaron necesitar una evaluación más exhaustiva. En este grupo se encontró que el área del polígono de Posselt en el plano frontal, fue significativamente menor que el de aquellos participantes que no requieren una evaluación más exhaustiva (p=0,003). Los valores de la trayectoria de apertura mandibular varían según de que síntoma se trate. Los principales síntomas que afectarían los valores de los movimientos bordeantes son la "dificultad para abrir la boca" y el "ruido en las articulaciones mandibulares". Con este estudio, hemos puesto de manifiesto que la limitación del movimiento mandibular como signo de TTM debe evaluarse con cautela, debido a que según la presencia de determinados síntomas y otras características de los sujetos (como el sexo), su valor podría variar.

ABSTRACT: Both the limitation of mandibular movement and the self-report of symptoms of temporomandibular disorders (TMD) are used for the diagnosis of patients in clinical diagnosis. However, the relationship between the symptoms and mandibular movement is not entirely clear. Therefore, the objective of this study was to relate the presence of symptoms associated with TMD with mandibular movement in a sample of young and healthy adult subjects. This exploratory study involved 40 medically healthy dentistry students with a continuous and complete maxillary and mandibular arch (up to the first molar). Each subject was asked to answer a self-report questionnaire for symptoms associated with TTM recommended by the American Academy of Orofacial Pain (AAOP). We also recorded and analyzed their mandibular movements using 3D electromagnetic articulography, with the aim of correlating the presence of symptoms with the range and trajectory of opening, and the area included in what is described as a polygon of Posselt in the frontal and sagittal plane. No significant differences were found between the answers to each question between men and women. According to the responses and to Delcanho, 12 participants turned out to need a more exhaustive evaluation. In this group it was found that the area of the Posselt polygon in the frontal plane was significantly smaller than that of those participants who did not require a more extensive evaluation (p = 0.003). The values of the mandibular opening path vary depending on the symptom involved. The main symptoms that would affect the values of the bordering movements are the "difficulty to open the mouth" and "noise in the mandibular joints". With this study, we have shown that the limitation of mandibular movement as a sign of TMD should be assessed with caution, as, according to the presence of certain symptoms and other characteristics of subjects (such as sex), its value may vary.

Influence of Masticatory Behavior on Muscle Compensations During the Oral Phase of Swallowing of Smokers

Abstract Introduction Chewing and swallowing are physiologically interconnected functions, which share motor structures and supranuclear regions of the central nervous system (CNS), involving a sensorimotor synchrony. Objective To analyze the influence of masticatory behavior on muscular compensations in the oral phase of swallowing in smokers compared with nonsmokers. Methods A cross-sectional study comparing smokers and nonsmokers composed of 24 participants in each group. The aspects of food crunching, masticatory pattern, masticatory speed, atypical muscular contractions, and lip closure were analyzed during mastication. In swallowing, aspects of contraction of the orbicular and mental muscles, head movement and presence of deglutition, mastication, smoking, and of stomatognathic system of residues after swallowing were characterized. Results Statistically significant differences were identified between the study groups related to food grinding pattern, masticatory velocity, and mental contraction during swallowing. There was no significant association between masticatory function and compensations during swallowing. Conclusion Differences were observed in the pattern of chewing and swallowing in smokers compared with nonsmokers, but no influence of masticatory performance was observed in the presence of muscle compensations during the oral phase of swallowing.

Estudo das variáveis cinemáticas da mastigação unilateral e habitual de indivíduos saudáveis / Study of the kinematic variables of unilateral and habitual mastication of healthy individuals

RESUMO Objetivo Descrever e comparar as variáveis cinemáticas temporoespaciais do movimento mandibular durante a mastigação unilateral deliberada e habitual de indivíduos saudáveis. Método Participaram do estudo 8 voluntários saudáveis, do gênero masculino, com faixa etária entre 19 e 24 anos. Os dados cinemáticos foram obtidos através do sistema de análise de movimento Qualysis (QTM - Qualisys Track Manager). Foram realizados registros de mastigação unilateral direita (MU) e habitual (MH) de bala de goma de gelatina de consistência firme. Foram analisadas variáveis relacionadas à (1) sequência mastigatória (duração, número de ciclos e frequência mastigatória); (2) ciclo mastigatório: duração do ciclo mastigatório, amplitude de movimento mandibular vertical e médio-lateral durante o ciclo mastigatório, velocidade máxima durante as fases de abertura e fechamento. A comparação das variáveis durante a MU e MH foi realizada por meio do teste t pareado (p<0,05) e os tamanhos de efeito (‘d’ de Cohen) foram calculados. Resultados Em relação à sequência mastigatória, observou-se menor frequência mastigatória durante MU comparada à MH (1,19±0,21 e 1,29±0,16Hz, respectivamente, p=0,004, d=0,53) e menores velocidades máximas de abertura (MU=67,4 mm/s e MH=80,02; p=0,053; d=0,80) e fechamento (MU=71,77±9,35mm/s e MH=83,51±17 mm/s, p=0,014, d=0,79) do ciclo mastigatório. Conclusão As variáveis cinemáticas relacionadas à sequência e ao ciclo mastigatório foram influenciadas pelo padrão mastigatório adotado – unilateral ou habitual.

ABSTRACT Purpose To describe and compare the temporal-spatial kinematic variables of mandibular movement during deliberate unilateral and habitual mastication in healthy young-adult individuals. Methods The study sample was composed of eight male healthy volunteers aged 19 to 24 years. The kinematic data were obtained using a motion analysis system - Qualisys Track Manager (QTM) ProReflex MCU. Recordings were performed during deliberate unilateral mastication (UM) and habitual mastication (HM) of firm-consistency gummy candy. The following variables were analyzed: (1) masticatory sequence: duration, number of masticatory cycles, and chewing rate; (2) masticatory cycle: duration, vertical and medial-lateral mandibular range of motion in relation to the skull, and maximum velocity during the opening and closing phases. Data of the variables were compared during UM and HM by the paired t test, and the effect sizes ('d' Cohen) were calculated. Results Regarding the variables of the masticatory sequence, smaller chewing rate was observed for UM compared with that for HM (1.19±0.21Hz and 1.29±0.16Hz, respectively, p=0.004, d=0.53). Smaller values of maximum velocity during the opening (MU=67.4 mm/s and MH=80.02, p=0.053, d=0.80) and closing (MU=71.77±9.35mm/s and MH=3.51±7mm/s, p=0.014, d=0.79) phases of the masticatory cycle were observed in deliberate unilateral mastication compared with those in habitual mastication. Conclusion Kinematic variables associated with the sequence and cycle of mastication are influenced by the chewing pattern adopted - deliberate unilateral or habitual.

Association between severe asthma and changes in the stomatognathic system / Associação entre asma grave e alterações do sistema estomatognático

ABSTRACT Objective: To describe orofacial muscle function in patients with severe asthma. Methods: This was a descriptive study comparing patients with severe controlled asthma (SCA) and severe uncontrolled asthma (SUA). We selected 160 patients, who completed a sociodemographic questionnaire and the 6-item Asthma Control Questionnaire (ACQ-6), as well as undergoing evaluation of orofacial muscle function. Results: Of the 160 patients evaluated, 126 (78.8%) and 34 (21.2%) presented with SCA and SUA, respectively, as defined by the Global Initiative for Asthma criteria. Regardless of the level of asthma control, the most frequent changes found after evaluation of muscle function were difficulty in chewing, oronasal breathing pattern, below-average or poor dental arch condition, and difficulty in swallowing. When the sample was stratified by FEV1 (% of predicted), was significantly higher proportions of SUA group patients, compared with SCA group patients, showed habitual open-mouth chewing (24.8% vs. 7.7%; p < 0.02), difficulty in swallowing water (33.7% vs. 17.3%; p < 0.04), and voice problems (81.2% vs. 51.9%; p < 0.01). When the sample was stratified by ACQ-6 score, the proportion of patients showing difficulty in swallowing bread was significantly higher in the SUA group than in the SCA group (66.6% vs. 26.6%; p < 0.01). Conclusions: The prevalence of changes in the stomatognathic system appears to be high among adults with severe asthma, regardless of the level of asthma control. We found that some such changes were significantly more common in patients with SUA than in those with SCA.

RESUMO Objetivo: Descrever os achados da avaliação miofuncional orofacial em pacientes com asma grave. Métodos: Estudo descritivo comparando pacientes com asma grave controlada (AGC) e asma grave não controlada (AGNC). Foram selecionados 160 participantes, que responderam a um questionário sociodemográfico e o Asthma Control Questionnaire com seis questões (ACQ-6) e realizaram avaliação miofuncional orofacial. Resultados: Na amostra estudada, 126 (78,8%) e 34 (21,2%) pacientes, respectivamente, apresentavam AGC e AGNC segundo os critérios da Global Initiative for Asthma. Independentemente do nível de controle da asma grave, as alterações mais frequentes observadas na avaliação miofuncional foram problemas de mastigação, padrão de respiração oronasal, estado de conservação da arcada dentária médio ou ruim e problemas na deglutição. Quando a amostra foi estratificada pelo VEF1 (% do previsto), os resultados foram significativamente maiores no grupo AGNC que no grupo AGC quanto a mastigação habitual com boca aberta (24,8% vs. 7,7%; p < 0,02), deglutição de água com dificuldade (33,7% vs. 17,3%; p < 0,04) e problemas de voz (81,2% vs. 51,9%; p < 0,01). Quando estratificada pelo ACQ-6, os resultados do grupo AGNC foram significativamente maiores que no grupo AGC quanto à deglutição de pão com dificuldade (66,6% vs. 26,6%; p < 0,01). Conclusões: A prevalência de alterações do sistema estomatognático parece ser alta em adultos com asma grave independentemente do nível de controle da doença. No grupo AGNC, algumas dessas alterações foram significativamente mais frequentes que no grupo AGC.

Evaluación de la fuerza masticatoria máxima funcional en adultos jóvenes chilenos / Evaluation of functional maximum bite force in Chilean young adults

La fuerza masticatoria máxima funcional (FMMF) se ha definido como la máxima fuerza generada entre los dientes maxilares y mandibulares. Así el objetivo de esta investigación fue de obtener datos reales sobre las FMMF a nivel molar, premolar, canino e incisivo en individuos adultos jóvenes. El estudio incluyó una muestra de 50 individuos entre 18 y 25 años de edad, totalmente dentados y con perfil esqueletal tipo I y clase I molar y canino. Se utilizó como instrumento un dispositivo de medición de fuerzas portátil, realizando las medidas en la región molar, premolar, canina e incisiva. A los individuos se les indicó morder el instrumento con la mayor fuerza posible, alternando las diferentes zonas a medir, aplicándose tres mediciones en cada diente y registrando el mayor valor en cada zona. La media de las fuerzas ejercidas del sexo masculino fue de 698, 516, 322 y 220 N, en las regiones molar, premolar, canina e incisiva, respectivamente. Por otro lado, en el sexo femenino se observaron valores medios de 466, 431, 232 y 174 N en las regiones molar, premolar, canina e incisiva, respectivamente. Se puede concluir que se observaron diferencias significativas de FMMF entre ambos sexos en las diferentes regiones, identificando los mayores valores en los individuos de sexo masculino en la región molar. Además, se identificaron diferencias significativas de la FMMF sólo en la región canina del sexo masculino al relacionarlas con el lado del arco.

The Functional maximum bite force (FMMF) is defined as the maximum force generated between the maxillary and mandibular teeth. Therefore, the aim of this research was to obtain real data about the FMMF at a molar, premolar, canine and incisive level in young adult individuals. The study included a sample of 50 individuals between 18 and 25 years old, fully toothed with a skeletal type I and Class I molar and canine profile. The measuring instrument used was a portable force measuring device, making measurements in the molar, premolar, canine and incisive regions. Individuals were instructed to bite the instrument with the greatest possible force, alternating different areas to measure, applying three measurements on each tooth and recording the highest value in each zone. The average of the forces exerted by males was 698, 516, 322 and 220 N, in the molar regions, premolar, canine and incisor, respectively. Furthermore, in females average values of 466, 431, 232 and 174 N were observed in the molar, premolar, canine and incisor regions respectively. It can be concluded that significant differences were observed in the FMMF between the sexes in different regions, identifying the highest values in male subjects in the molar region. In addition,significant differences were identified in the FMMF of males only in the canine region when related to the side of the arch.

Rendimiento masticatorio en pacientes rehabilitados con prótesis total removible v/s prótesis Ad-Modum Branemark / Masticatory performance in patients rehabilitated by means of removable complete dentures vs. Ad-Modum Branemark prostheses

Propósito: el propósito de este estudio fue evaluar y comparar el rendimiento masticatorio de pacientes desdentados totales rehabilitados mediante (prótesistipo Ad-Modum y/o prótesis removibles convencional. Método: Se evaluaron24 pacientes divididos en 3 grupos de ocho pacientes. Grupo Ipacientes rehabilitados con prótesis Ad-Modum bimaxilar, Grupo IIpacientes rehabilitados con prótesis Ad-Modum inferior y prótesis total removible superior, Grupo III pacientes rehabilitados con prótesis total removible bimaxilar. Se solicitó a cadapaciente realizar 20 golpes masticatorios a una pastilla de silicona previamente estandarizada, a la muestra obtenida se le realizó tamizado múltiple y los resultados fueron procesados con la fórmula de obtención de rendimiento masticatorio propuesta por el protocolo de Edlund y Lamm en 1980. Resultados: Lospromedios de rendimiento masticatorio fueron: Grupo I(15,6 por ciento±3,4), Grupo II (4,3 por ciento±4,6), Grupo III (0,3 por ciento±0,7). Mediante test de Tukey se demostró que existendiferencias significativas entre el grupo I y II, pero no entre los Grupos II yIII. Conclusiones: El tratamiento con prótesis Ad-Modum bimaxilar logró elmejor rendimiento masticatorio entre los 3 tratamientos rehabilitadores evaluados, el tratamiento con prótesis total removible superior y Ad-Modum inferior fue más exitoso en términos de rendimiento masticatorio que el grupo rehabilitado con prótesis total removible bimaxilar. Los tratamientos con prótesis removible total convencional, no otorgan al paciente una óptima función masticatoria

Comparação de dois métodos de avaliação da posição da cabeça da mandíbula na fossa mandibular por imagem de ressonância magnética / Comparison of two methods for evaluation the position of the condyle in the articular fossa by magnetic resonance imaging

A Disfunção Temporomandibular (DTM) é um termo que remete ao conjunto de doenças que envolvem músculos mastigatórios, articulação temporomandibular (ATM) e estruturas associadas. Diversos estudos buscam uma ligação entre sinais e sintomas de pacientes com DTM, tentando correlacionar o posicionamento de estruturas anatômicas, especificamente disco articular e cabeça da mandíbula, com a presença de dores nas ATMs, nos músculos mastigatórios e posturais. No que se refere à posição da cabeça da mandíbula na fossa mandibular, a literatura relata existir uma grande variação, sendo que os conceitos de normalidade e anormalidade são controversos. Os estudos sobre DTM evoluíram ao longo dos anos, principalmente nas últimas três décadas, graças ao advento de técnicas de exames de imagem como a Tomografia Computadoriza (TC) e a Ressonância Magnética (RM). Atualmente a RM é considerada o melhor método de avaliação de imagem para se estudar a ATM, tanto nos aspectos anatômicos e fisiológicos de normalidade, quanto nos aspectos patológicos, complementando o exame clínico de pacientes com DTM. O objetivo principal desse estudo foi a comparação do método de Pullinger-Hollender (P-H) com o método de Gelb quanto à posição da cabeça da mandíbula (anterior, concêntrica ou posterior) avaliada no exame de ressonância magnética (cortes centrais sagitais ponderados em T1) de 60 pacientes (42 mulheres e 18 homens) diagnosticados com DTM...

The term Temporomandibular Disorder (TMD) refers to the group of diseases that involves the masticatory muscles, temporomandibular joint (TMJ) and associated structures. Several studies have sought a link between signs and symptoms of TMD patients, trying to correlate the position of anatomical structures, specifically articular disc and condyle, with the presence of pain in the TMJ, masticatory and postural muscles. As regards the position of the condyle in the articular fossa, the literature reports a wide variation and the concepts of normality and abnormality are controversial. Nevertheless, the methods described to measure this placement do not follow a pattern. Studies on DTM have evolved over the years, especially in the last three decades, thanks to the advent of techniques of imaging tests such as Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). MRI is currently considered the best method of imaging evaluation to study the TMJ both anatomical and physiological aspects of normality as the pathological aspects, complementing the clinical examination of patients with TMD. The main objective of this study was to analyze the position of the condyle in the articular fossa (anterior, posterior or concentric) using comparison of the PullingerHollender method (PH) with the Gelb method evaluated the MRI (sagittal central sections T1- weighted) 60 patients (42 women and 18 men) diagnosed with TMD. The secondary objective was to evaluate the inter-judge agreement in the application of the two methods. Each judge reproduced two drawings of each selected interval of 30 days between them, which were placed in four separate envelopes cut and later was chosen randomly one of them, the rest were discarded...

Asimetrías faciales como factor etiopatogénico de cefaleas y dolor facial / Facial asymmetries as etiopathogenic factors of headache and facial pain

El objetivo de este estudio fue demostrar la hipótesis sobre la coexistencia de asimetría morfológica con actividad muscular asimétrica, y deesta última con disfunción cráneomandibular y cefalea tensional y dolor facial, para incorporar datos semiológicos al diagnóstico tempranoy tratamiento precoz de las disfunciones cráneo-cérvico mandibulares. Participaron del estudio 66 alumnos de la F.O.U.B.A. con signos y/o síntomas de disfunción cráneomandibular. El diagnóstico de dolor se realizó mediante cuestionarios siguiendo los criterios diagnósticos de la Internacional Headache Society. La determinación de asimetría se realizó midiendo segmentos y ángulos trazados en telerradiografíade frente para tejidos duros y fotografía de cara de frente para tejidos blandos. Se evaluó la función muscular mediante electromiografía de superficie (EMGS); y la dinámica del sistema estomatognático mediante el método magnetométrico. El análisis de regresión logística múltiple resultó significativo al nivel p=0.01. En el análisis de las variables individuales y el dolor se encontró correlación estadísticamente significativa entre la asimetría de tejidos duros y la presencia de cefalea tensional y/o dolor facial. El organismo intenta equilibrar las diferencias morfológicas, esto explicaría las asimetrías cruzadas entre tejidos duros, blandos y actividad muscular comocompensaciones funcionales. Concluimos diciendo que ante la presencia de cefalea tensional y/o dolor facial debemos considerar la asimetríafacial de tejidos duros como posible factor etiológico predisponente aunque no se observe asimetría en tejidos blandos por acción compensatoria de la dinámica muscular. La etiología mixta, oclusal y postural, de las asimetrías faciales requiere del trabajo interdisciplinario odontólogo-médico-kinesiólogo-psicólogo-fonoaudiólogo para un óptimo diagnóstico y tratamiento

The aim of this study was to test the hypothesis on the coexistence of morphological asymmetry with asymmetric muscle activity, and this one with craniomandibular dysfunction and tension headache and facial pain, to incorporate semiological data to early diagnosis and treatment for TMJD (temporo mandibular jaw dysfunction). Study participants were 66 students from the Faculty of Dentistry of the University of Buenos Aires with TMJD signs and / or symptoms. The diagnosis of pain was conducted by questionnaires following the diagnostic criteria of the International Headache Society. The asymmetry determination was performed by measuring segments and angles in cephalometric frontal tracings for hard tissues and frontal picture for soft tissues. Muscle function was evaluated by surface electromyography (SEMG) and stomatognathic system dynamics by magnetometric method. The multiple logistic regression analysis was significant at p = 0.01. In the analysis of individual variables and pain we found statistical correlation between the asymmetry of hard tissues and the presence of tension headache and / or facial pain. The body tries to balance the morphological differences; this would explain the asymmetries cross between hard tissues, soft and functional muscle activity as offsets. We conclude saying that in the presence of tension headache and/or facial pain, the hard tissue facial asymmetry should be considered as a possible etiologic factor predisposing even asymmetry is not observed in soft tissue because of compensatory action of muscle dynamics. The mixed etiology, occlusal and postural of the facial asymmetries, requires interdisciplinary work dentist-doctor-physiotherapist,-psychologist-speech therapist, for optimal diagnosis and treatment.

Presentación y análisis de una nueva variable para el estudio electromiográfico de la función cráneo-mandibular. Estudio piloto / Presentation and analysis of a new variable for eletromyographic study of the function skull-jaw. Pilot study

Objetivos. A pesar de décadas de investigación en el área de la electromiografía, su empleo en odontología es aún controversial, debido a la baja sensibilidad de las variables estudiadas. Se definió y analizó una nueva variable, que es la capacidad del individuo para controlar su trayectoria muscular durante un esfuerzo voluntario estandarizado, con el objetivo de analizar posibles patrones de normalidad.Métodos. Se utilizó retroalimentación visual para controlar el esfuerzo contráctil de los músculos masetero, trapecio y frontal. Se midió, para cada músculo, el tiempo que cada individuo necesitó para controlar la trayectoria de la actividad motora.Resultados. Se demostró que la capacidad de una persona sana para controlar esa trayectoria era diferente para los músculos inervados por distintos pares craneales. Un posible patrón de “normalidad” fue más evidente en los músculos maseteros.Conclusiones. Se define y analiza, en un trabajo piloto, una nueva variable para el estudio de la función cráneo-mandibular. Se requerirá un futuro estudio, con una muestra ampliada, para confirmar estos resultados preliminares.

Objectives. Despite decades of research in the area of electromyography, its use in dentistry is still controversial because low sensitivity of the proposed variables. We defined and analyzed a new variable, which is the ability of the subject to control the muscle force trajectory, with the aim to find possible normality patterns.Methods. Real-time visual biofeedback was used to control the muscle force trajectory of the masseter, trapezius and frontal muscles. We measured the time that each individual needed to control the trajectory under a standardized set of experimental conditions.Results. We showed that the ability to control the muscle force trajectory can vary for muscles innervated by different cranial nerves. A possible ¨normality¨ pattern was more evident in the masseter muscle.Conclusions. We defined and analyzed, in a pilot research, a new variable for the study of the craniomandibular function. Further research, with an increased sample size, will be needed in order to confirm these preliminary results.

The effect of a Lucia jig for 30 minutes on neuromuscular re-programming, in normal subjects

The Lucia jig is a technique that promotes neuromuscular reprogramming of the masticatory system and allows the stabilization of the mandible without the interference of dental contacts, maintaining the mandible position in harmonic condition with the musculature in normal subjects or in patients with temporomandibular dysfunction (TMD). This study aimed to electromyographically analyze the activity (RMS) of the masseter and temporal muscles in normal subjects (control group) during the use of an anterior programming device, the Lucia jig, in place for 0, 5, 10, 20 and 30 minutes to demonstrate its effect on the stomatognathic system. Forty-two healthy dentate individuals (aged 21 to 40 years) with normal occlusion and without parafunctional habits or temporomandibular dysfunction (RDC/TMD) were evaluated on the basis of the electromyographic activity of the masseter and temporal muscles before placement of a neuromuscular re-programming device, the Lucia jig, on the upper central incisors. There were no statistically significant differences (p < 0.05) in the electromyographic activity of the masticatory muscles in the different time periods. The Lucia jig changed the electromyographic activity by promoting a neuromuscular reprogramming. In most of the time periods, it decreased the activation of the masticatory muscles, showing that this device has wide applicability in dentistry. The use of a Lucia jig over 0, 5, 10, 15, 20 and 30 minutes did not promote any statistically significant increase in muscle activity despite differences in the data, thus showing that this intra-oral device can be used in dentistry.

Trastornos temporomandibulares en adictos al qat / Temporomandibular disorders in qat addicted people

Introducción: los trastornos temporomandibulares se asocian frecuentemente al hábito de masticar qat, pero se carece de estudios que detallan sus particularidades, por lo que se realiza este trabajo, con los objetivos de determinar la prevalencia de trastornos temporomandibulares en pacientes adictos al qat, identificar los hallazgos clínicos-radiográficos asociados y clasificar los trastornos temporomandibulares presentes en la población estudiada. Métodos: se realizó un estudio prospectivo, descriptivo, de corte transversal, en una muestra de 352 pacientes, del total de pacientes adictos, atendidos en el Departamento de Cirugía, Colegio Dental. Ibb, Yemen en el periodo octubre 2010-abril 2011. Se determinaron los hallazgos clínicos y radiográficos presentes y se diagnosticó el tipo de trastorno temporomandibular. Resultados: se evidenció que estaban afectados por trastornos temporomandibulares el 55,7 por ciento de los pacientes. Se encontró dolor articular agudo en 14,1 por ciento y aplanamiento condilar anterior en 35,6 por ciento. Conclusiones: los trastornos temporomandibulares afectaron más de la mitad de la población estudiada, adicta al qat. Los desórdenes en la relación cóndilo-disco fueron los más encontrados (41 por ciento). El aplanamiento condilar anterior dominó en el análisis radiográfico(AU)

Introduction: the temporomandibular disorders has been associated frequently to the habit of chewing qat, but in previous studies, there are lack of specific details of this problem, for this reason this study is carried out ,to determine it prevalence, to identify clinical and radiografical findings associated , and to classify the temporomandibular disorders observed in the sample. Methods: a cross-sectional, descriptive and prospective study was done, in a sample of 352 patients of the total qat addicted patients which came to the Department of surgery, Dentistry College .Ibb Yemen October 2010-April 2011. The clinical and radiographical findings were recorded and the temporomandibular disorders were classified. Results: 55.7 percent of patients were affected of temporomandibular disorders. Acute Joint pain (14.1) and anterior condylar flattening (35.6 percent) were the most frequents. Conclusions: the Temporomandibular disorders affected more than half of the population of studied qat addicted population, with prevalence of disorders in the disc-condyle relation (41percent).The anterior condylar flattening was very evident(AU)

Chewing side, bite force symmetry, and occlusal contact area of subjects with different facial vertical patterns

Craniofacial dimensions influence oral functions; however, it is not known whether they are associated with function asymmetry. The objective of this study was to evaluate chewing side preference and lateral asymmetry of occlusal contact area and bite force of individuals with different craniofacial patterns. Seventy-eight dentate subjects were divided into 3 groups according to the VERT index as follows: (1) mesofacial, (2) brachyfacial and (3) dolichofacial. Chewing side preference was evaluated using jaw tracking equipment, occlusal contact area was measured by silicon registration of posterior teeth, and bite force was measured unilaterally on molar regions using 2.25 mm-thick sensors. Statistical analysis was performed using ANOVA on Ranks, Student's t-test, and Mann-Whitney tests at a 5 percent significance level. Mesofacial, brachyfacial, and dolichofacial subjects presented more occlusal contact area on the left side. Only dolichofacial subjects showed lateral asymmetry for bite force, presenting higher force on the left side. No statistically significant differences were found for chewing side preference among all groups. Within the limitations of this study, it can be concluded that craniofacial dimensions play a role in asymmetry of bite force. ClinicalTrials.gov ID: NCT01286363.

Occlusal force, electromyographic activity of masticatory muscles and mandibular flexure of subjects with different facial types

OBJECTIVE: The aim of this study was to evaluate whether vertical facial patterns influence maximal occlusal force (MOF), masticatory muscle electromyographic (EMG) activity, and medial mandibular flexure (MMF). MATERIAL AND METHODS: Seventy-eight dentate subjects were divided into 3 groups by Ricketts's analysis: brachyfacial, mesofacial and dolychofacial. Maximum occlusal force in the molar region was bilaterally measured with a force transducer. The electromyographic activities of the masseter and anterior temporal muscles were recorded during maximal voluntary clenching. Medial mandibular flexure was calculated by subtracting the intermolar distance of maximum opening or protrusion from the distance in the rest position. The data were analyzed using ANOVA followed by Tukey's HSD test. The significance level was set at 5 percent. RESULTS: Data on maximum occlusal force showed that shorter faces had higher occlusal forces (P<0.0001). Brachyfacial subjects presented higher levels of masseter electromyographic activity and medial mandibular flexure, followed by the mesofacial and dolychofacial groups. Additionally, dolychofacial subjects showed significantly lower electromyographic temporalis activities (P<0.05). CONCLUSION: Within the limitations of the study, it may be concluded that maximum occlusal force, masticatory muscle activity and medial mandibular flexure were influenced by the vertical facial pattern.

Influence of female hormonal fluctuation on maximum occlusal force

Hormonal fluctuations during the menstrual cycle may influence on muscular tensions and probably alter occlusal force. The aim of this study was to evaluate whether hormonal levels affect maximum occlusal force (MOF) of healthy women throughout the different phases of the menstrual cycle. Sixty complete dentate subjects who were not under use of oral contraceptives were selected to participate in this study. MOF was bilaterally evaluated on the molar region, during 3 complete menstrual cycles, using 5.65 mm-wide sensors. Measurements were carried out during each of the following menstrual cycle phases: menstrual, follicular, periovulatory and luteal, presumed by ovulation test. Data were analyzed by one-way ANOVA and Tukey-Kramer test (p<0.05). Comparisons among menstrual cycle phases showed no differences on MOF (p=0.27). Under the conditions of this study, it may be concluded that hormonal fluctuations during the menstrual cycle do not affect MOF of a sample of healthy women.

As flutuações hormonais durante o ciclo menstrual podem influenciar as tensões musculares e possivelmente alterar a força oclusal. O objetivo deste estudo foi avaliar se os níveis hormonais afetam a força máxima oclusal (FMO) de mulheres saudáveis durante as diferentes fases do ciclo menstrual. Sessenta pacientes completamente dentadas que não usavam contraceptivos orais foram selecionadas para participar neste estudo. FMO foi avaliada bilateralmente na região dos molares, durante 3 ciclos menstruais completos, utilizando sensores de 5,65 mm de espessura. As mensurações foram realizadas durante cada fase do ciclo menstrual: menstrual, folicular e lútea periovulatória, identificadas por teste ovulatório. Os dados foram analisados por ANOVA um critério seguido do teste de Tukey-Kramer (p<0,05). As comparações entre as fases do ciclo menstrual não apresentaram diferenças na FMO (p=0,27). Segundo as condições deste estudo, pode-se concluir que as flutuações hormonais durante o ciclo menstrual não afetaram a FMO de mulheres saudáveis.

Characteristics of masticatory muscles in children with unilateral posterior crossbite

The aim of this study was to detect possible differences in the EMG (electromiography) activity, chewing rate (CR), cycle duration (CD) and preferred chewing side (PCS) between children with and without unilateral posterior crossbite. Thirty-seven children aged from 7 to 10 years were selected from the clinic of the Department of Pediatric Dentistry, Piracicaba Dental School, Brazil, and divided into two groups: unilateral posterior crossbite (UPCB group, n = 17), and normal occlusion (NOccl group, n = 20). The PCS was determined using a visual spot-checking method. The EMG activity was recorded during mastication, and two chewing sequences of 20 s were evaluated to establish each subject's CR (cycles/sec) and CD. UPCB and NOccl groups did not have a PCS. The EMG activity and the cycle characteristics did not differ between the groups. The correlations between CD, CR and EMG activity were statistically significant for the masseter and anterior temporalis muscles only in the NOccl group, in which there was also a significant correlation between the EMG activity of masseter and anterior temporalis. In conclusion, these findings suggest that although children with and without UPCB presented a bilateral masticatory pattern with similar CR and CD, balanced EMG activity of masseter and anterior temporalis muscles was observed only in the NOccl group. These results indicate that in children, UPCB can alter the coordination of masticatory muscles during mastication.

Confiabilidade da eficiência mastigatória com beads e correlação com a atividade muscular / Reliability of masticatory efficiency with beads and correlation with the muscle activity

TEMA: a avaliação da eficiência mastigatória pela análise colorimétrica com beads, pode ser um método promissor, mas não há relatos sobre a sua confiabilidade. OBJETIVO: investigar a confiabiabilidade das beads para teste de eficiência mastigatória e a correlação com a atividade eletromiográfica dos músculos masseter e temporal anterior. MÉTODO: participaram dezenove sujeitos adultos jovens, nove do gênero masculino e dez do feminino com idades entre dezoito e vinte-oito anos, com dentição completa, sem histórico de desordem temporomandibular, trauma, cirurgia na região de cabeça e pescoço, tratamento ortodôntico ou fonoaudiológico. O teste de eficiência mastigatória foi realizado com beads nas condições: mastigação habitual, mastigação unilateral direita e esquerda, com duração de 20 segundos. Simultaneamente, foi realizada a eletromiografia. A atividade em máxima intercuspidação habitual dos dentes também foi registrada. A quantidade de fucsina liberada após a mastigação foi medida usando o espectrofotômetro Beckman DU-7 UV-Visible (Beckman Inc., Palo Alto, CA, USA). RESULTADOS: houve alta confiabilidade do teste de eficiência mastigatória (r = 0,86, p < 0,01) e correlação significante com a atividade eletromiográfica (r = 0,76, p < 0,01). Também houve correlações positivas quando as provas foram analisadas separadamente. CONCLUSÃO: o teste de eficiência mastigatória realizado com beads mostrou-se um método confiável e correlacionado positivamente à atividade eletromiográfica dos músculos temporal anterior e músculos masseter.

BACKGROUND: the use of the colorimetric method with beads to evaluate mastigatory efficiency may be promising, however no report is found about its reliability. AIM: to investigate the reliability of the beads to test masticatory efficiency and its correlation with the electromyographic activities of the anterior temporal and masseter muscles. METHODS: participants of this study were nineteen young adults, nine males and ten females, aged eighteen to twenty-eight years, with full dentition, Angle class I, with no history of temporomandibular disorder, neurological or cognitive deficit, previous or current tumors or traumas in the head and neck region, and orthodontic treatment or orofacial myofunctional therapy. The masticatory efficiency test was performed using beads, fuchsine-containing granules, in the folowing conditions: habitual chewing, right and left unilateral chewing, for 20 seconds. Electromyographic recordings were obtained simultaneously. Also, the maximal clenching was registered. The amount of fuchsin released upon chewing was measured using a Beckman DU-7 UV-Visible Spectrophotometer (Beckman Inc., Palo Alto, CA, USA). RESULTS: high reliability was observed for the masticatory efficiency test (r = 0.86, p < 0.01) and correlation with the electromyographic activities (r = 0.76, p < 0.01). Also, positive and significant correlations were observed when the conditions were separately analyzed. CONCLUSION: the masticatory efficiency test performed with beads proved to be a reliable method and positively correlated to the electromyographic activities of the anterior temporal and masseter muscles.