Dados do Trabalho

Título

Test-retest of measurements of the electromyographic signal on masseter and temporal muscles in patients with Down syndrome

Introdução

To our knowledge, no studies have accessed the reliability or the reproducibility of the nonlinear surface electromyography (sEMG) variables of the masseter and temporalis muscles in adults with DS. Therefore, it is important to determine the variation in EMG signals measurements (intra-day and inter-day reliability) prior to suggest the use of EMG as a tool for evaluating the efficacy of therapies applied to the investigation and improvement of the masticatory muscles function in this population.

Objetivo

The aim of the present study was to evaluate intra-day (test) and inter-day (re-test) reliability of surface electromyography (sEMG) signals of the masseter and temporal muscles in individuals with Down syndrome (DS).

Métodos

The reliability of the EMG variables was verified in twenty-three individuals with DS. The inclusion criteria were adult individuals aged between 18-35 years-old, preserved cognitive function (ability to understand and respond to verbal commands necessary to perform this study, such as "open the mouth", "close the mouth", " bite", "relax"), agreed to participate by free will and written consent signed by patient or patient’s responsible. The sEMG was performed at rest, at maximum voluntary clenching effort (MVC) and at maximum habitual intercuspation effort (MHI). The EMG signal was analyzed using the root mean square amplitude (RMS), mean frequency (MNF), median frequency (MDF) and approximate entropy (apEn). Values near 0 indicate the presence of illness or dysfunction and values near 2 indicate the absence of illness or dysfunction.

Resultados

The intraclass correlation (ICCs) for the three trials recorded in MHI in two session (test and retest) revealed excellent within-and-inter session reliability (range: 0.76 to 0.97) for all EMG parameters and muscles recorded in MHI. At rest position it was seen an excellent reliability for RMS and ApEn (range: 0.75 to 1.00); good and excellent reliability MDF e MNF (range: 0.64 to 0.93).

Conclusões

Test-retest showed the reliability and the reproducibility of the nonlinear sEMG variables of the masticatory muscles in adults with DS. These measures will give confidence to professionals perform studies on masticatory muscles behavior (e.g. sleep and awake bruxism), as well as evaluate the results of treatment, with high confidence, in this population. In addition, it will be useful to choose the best therapeutic approach in DS individuals.

Palavras-chave

Down syndrome; test-retest; Electromyography; reliability; masticatory muscles