Shear wave elastography is a valuable tool for diagnosing and grading carpal tunnel syndrome.

OBJECTIVE: To quantify the shear velocity and stiffness of the median nerve (MN) with shear wave elastography (SWE) at the carpal tunnel entrance and determine whether SWE is useful for diagnosing and staging carpal tunnel syndrome (CTS). MATERIALS AND METHODS: The study included 58 patients (79 wrists) with clinical and electroneuromyographic diagnoses of CTS and 55 healthy controls (63 wrists). MN shear velocity and stiffness were measured by SWE on the axial plane in both groups. The differences between CTS patients and controls and between different grades of CTS based on electrodiagnostic tests were studied using Student's t test and ANOVA with ROC analysis. RESULTS: The mean MN shear velocity and stiffness were significantly greater in CTS patients (2.5 ± 0.37 m/s and 19.4 ± 5.8 kPa) than in controls (1.91 ± 0.24 m/s and 11.1 ± 3.0 kPa) (p < 0.001) and greater in the severe CTS group (2.69 ± 0.39 m/s and 22.4 ± 7.1 kPa) than in the mild CTS group (2.37 ± 0.35 m/s and 17.3 ± 4,8 kPa). The cutoff value for the shear velocity was 2.13 m/s, with 86% and 82% sensitivity and specificity, respectively, and the cutoff value for stiffness was 13.6 kPa, with 87% and 82% sensitivity and specificity. CONCLUSION: MN shear velocity and stiffness are significantly higher in CTS patients. SWE can be used to diagnose CTS and distinguish between patients with mild and severe disease.

Electromyographic and ultrasonographic characterization of masticatory function in individuals with normal occlusion.

PURPOSE: To characterize the motor control of the masseter and temporal muscles and the morphology of the masseter muscles during mastication in individuals with normal occlusion and to verify the consistency between surface electromyography (sEMG) and ultrasound (USD). METHODS: Participants were 22 adults, of both genders, with no alterations of the oral myofuntional system. The procedures performed included sEMG of the masseter (MM) and temporal (TM) muscles and USD of the MM, each during three tasks: resting condition and maximum voluntary dental clench with and without cotton rolls. RESULTS: The following statistical tests were used: Kolmogorov-Smirnov, paired t-test and Spearman correlation (significance level of 5%). The sEMG data indicated a significant difference between the MM and TM during the maximum voluntary clench with and without cotton rolls, and the TM was more active than the TM in both clenching tasks. No significant difference was observed between the sides of the face when assessed with sEMG or USD. A significant positive correlation between the exams was observed for the left maximum voluntary dental clench with and without cotton rolls, and a trend toward significance was found for the right maximum dental clench without cotton rolls. CONCLUSION: The comparison of sEMG to USD for the investigation of muscle function reveals important information about the physiology of skeletal muscles. The results of the present study suggest a correlation between sEMG and USD, i.e., between increased electrical activity and the corresponding increase in muscle thickness.

Electromyographic and ultrasonographic assessment of the masseter muscle in normal individuals: a pilot study.

BACKGROUND: recent studies have used ultrasonography with the purpose of measuring muscle cuts. AIM: to characterize the motor control and the morphology of the masseter muscle in normal individuals, verifying the compatibility between surface electromyography and ultrasonography. METHOD: five adult individuals, with no alterations of the stomatognathic system. The adopted assessment procedures for all participants were: 1. Surface Electromyography; 2. Ultrasonography. RESULTS: a high correlation was observed only when comparing both hemifaces in the ultrasonographic assessment (rest 0.95; biting 0.86). CONCLUSION: the results indicate that there is no correlation between the tested methods, suggesting that both methods are complementary and not mutually excludent.

Caracterização eletromiográfica e ultrassonográfica da função mastigatória em indivíduos com oclusão normal / Electromyographic and ultrasonographic characterization of masticatory function in individuals with normal occlusion

OBJETIVO: Caracterizar o controle motor dos músculos masseter e temporal e a morfologia do músculo masseter em atividades da função mastigatória em indivíduos com oclusão normal; verificar a compatibilidade entre os exames de eletromiografia de superfície (EMGs) e ultrassonografia (USG). MÉTODOS: Participaram 22 indivíduos adultos, de ambos os gêneros, sem alterações no sistema miofuncional orofacial. Os procedimentos adotados para avaliação dos participantes foram: EMGs dos músculos masseteres (MM) e temporais (MT); e USG dos MM, na realização de três tarefas - repouso muscular, apertamento dentário com algodão, apertamento dentário sem algodão. RESULTADOS: Para análise estatística dos dados foram utilizados os testes de Kolmogorv-Smirnov, teste-T pareado e Correlação de Spearman, com nível de significância de 5%. Na EMGs observou-se diferença entre a ativação de MM e MT no apertamento dentário com e sem algodão, sendo MT mais ativo que MM em ambas as tarefas. Não foram observadas diferenças entre as hemifaces, tanto na EMGs quanto na USG. Observou-se também correlação positiva entre os exames na condição de apertamento dentário sem algodão esquerdo e na condição de apertamento dentário esquerdo com algodão, e tendência à significância no apertamento dentário direito sem algodão. CONCLUSÃO: A associação da EMGs e USG na investigação da funcionalidade muscular traz importantes informações sobre fisiologia da musculatura esquelética. Os resultados do presente estudo indicam haver correlação entre a EMGs e a USG, ou seja, o aumento da atividade elétrica e o aumento correspondente da espessura do músculo.

PURPOSE: To characterize the motor control of the masseter and temporal muscles and the morphology of the masseter muscles during mastication in individuals with normal occlusion and to verify the consistency between surface electromyography (sEMG) and ultrasound (USD). METHODS: Participants were 22 adults, of both genders, with no alterations of the oral myofuntional system. The procedures performed included sEMG of the masseter (MM) and temporal (TM) muscles and USD of the MM, each during three tasks: resting condition and maximum voluntary dental clench with and without cotton rolls. RESULTS: The following statistical tests were used: Kolmogorov-Smirnov, paired t-test and Spearman correlation (significance level of 5%). The sEMG data indicated a significant difference between the MM and TM during the maximum voluntary clench with and without cotton rolls, and the TM was more active than the TM in both clenching tasks. No significant difference was observed between the sides of the face when assessed with sEMG or USD. A significant positive correlation between the exams was observed for the left maximum voluntary dental clench with and without cotton rolls, and a trend toward significance was found for the right maximum dental clench without cotton rolls. CONCLUSION: The comparison of sEMG to USD for the investigation of muscle function reveals important information about the physiology of skeletal muscles. The results of the present study suggest a correlation between sEMG and USD, i.e., between increased electrical activity and the corresponding increase in muscle thickness.

Avaliação eletromiográfica e ultrassonográfica do músculo masseter em indivíduos normais: estudo piloto / Electromyographic and ultrasonographic assessment of the masseter muscle in normal individuals: a pilot study

TEMA: estudos recentes utilizaram a ultrassonografia com o objetivo de medir cortes musculares. OBJETIVO: caracterizar o controle motor e a morfologia do músculo masseter em indivíduos normais, verificando a compatibilidade entre a eletromiografia de superfície e a ultrassonografia. MÉTODO: cinco indivíduos adultos, sem alterações no sistema estomatognático. Os procedimentos adotados para a avaliação dos participantes foram: 1. Eletromiografia de Superfície; 2. Ultrassonografia. RESULTADOS: houve alta correlação apenas para a comparação entre hemifaces direita e esquerda no exame de ultrassonografia (repouso 0,95; máxima intercuspidação dentária 0,86). CONCLUSÃO: os resultados indicam não haver correlação entre os métodos testados, sugerindo que os exames são complementares e não excludentes.

BACKGROUND: recent studies have used ultrasonography with the purpose of measuring muscle cuts. AIM: to characterize the motor control and the morphology of the masseter muscle in normal individuals, verifying the compatibility between surface electromyography and ultrasonography. METHOD: five adult individuals, with no alterations of the stomatognathic system. The adopted assessment procedures for all participants were: 1. Surface Electromyography; 2. Ultrasonography. RESULTS: a high correlation was observed only when comparing both hemifaces in the ultrasonographic assessment (rest 0.95; biting 0.86). CONCLUSION: the results indicate that there is no correlation between the tested methods, suggesting that both methods are complementary and not mutually excludent.