Surface electromyography pattern of human swallowing

Automatic Clinical Assessment of Swallowing Behavior and Diagnosis of Silent Aspiration Using Wireless Multimodal Wearable Electronics

Dysphagia is more common in conditions such as stroke, Parkinson's disease, and head and neck cancer. This can lead to pneumonia, choking, malnutrition, and dehydration. Currently, the diagnostic gold standard uses radiologic imaging, the videofluoroscopic swallow study (VFSS); however, it is expensive and necessitates specialized facilities and trained personnel. Although several devices attempt to address the limitations, none offer the clinical-grade quality and accuracy of the VFSS. Here, this study reports a wireless multimodal wearable system with machine learning for automatic, accurate clinical assessment of swallowing behavior and diagnosis of silent aspirations from dysphagia patients. The device includes a kirigami-structured electrode that suppresses changes in skin contact impedance caused by movements and a microphone with a gel layer that effectively blocks external noise for measuring high-quality electromyograms and swallowing sounds. The deep learning algorithm offers the classification of swallowing patterns while diagnosing silent aspirations, with an accuracy of 89.47%. The demonstration with post-stroke patients captures the system's significance in measuring multiple physiological signals in real-time for detecting swallowing disorders, validated by comparing them with the VFSS. The multimodal electronics can ensure a promising future for dysphagia healthcare and rehabilitation therapy, providing an accurate, non-invasive alternative for monitoring swallowing and aspiration events.

Surface Electromyography for Evaluating the Effect of Aging on the Coordination of Swallowing Muscles

Swallowing function can deteriorate with age, leading to a risk of dysphagia. Swallowing evaluation by surface electromyography (sEMG) can be easily and extensively applied for an elderly population. This study evaluated the temporal events observed by sEMG to clarify how aging affects the coordination among the masticatory and suprahyoid muscles. We recruited elderly individuals (over 65 years old) who denied dysphagia. The sEMG activities of anterior temporalis, masseter, and suprahyoid muscles were recorded during 3, 15, and 30 ml water swallowing tests (WST). We calculated the time interval between anterior temporalis and suprahyoid peak activity (T-SH interval) and masseter and suprahyoid peak activity (M-SH interval) and analyzed their correlation with age. The subjects who could and could not swallow 30 ml of water in one gulp were further assigned into the one-gulp and piecemeal groups, respectively, for subgroup analysis. We recruited 101 subjects, among whom 75 (26 males and 49 females) were analyzed after excluding those with suspected dysphagia or low-quality sEMG recordings. Age was significantly correlated with the bilateral T-SH (left: r = 0.249, p = 0.031; right: r = 0.412, p < 0.01) and right M-SH (r = 0.242, p = 0.037) intervals in the 30 ml WST. The correlation between intervals and age were observed in both subgroups. sEMG can be used to investigate the effect of aging on the temporal coordination between masticatory and suprahyoid contraction. Further studies are needed to verify the validity of screening subclinical dysphagia in the elderly.

Pilot Study: Magnetic Motion Analysis for Swallowing Detection Using MEMS Cantilever Actuators

The swallowing process involves complex muscle coordination mechanisms. When alterations in such mechanisms are produced by neurological conditions or diseases, a swallowing disorder known as dysphagia occurs. The instrumental evaluation of dysphagia is currently performed by invasive and experience-dependent techniques. Otherwise, non-invasive magnetic methods have proven to be suitable for various biomedical applications and might also be applicable for an objective swallowing assessment. In this pilot study, we performed a novel approach for deglutition evaluation based on active magnetic motion sensing with permanent magnet cantilever actuators. During the intake of liquids with different consistency, we recorded magnetic signals of relative movements between a stationary sensor and a body-worn actuator on the cricoid cartilage. Our results indicate the detection capability of swallowing-related movements in terms of a characteristic pattern. Consequently, the proposed technique offers the potential for dysphagia screening and biofeedback-based therapies.

Toward a robust swallowing detection for an implantable active artificial larynx: a survey

Total laryngectomy consists in the removal of the larynx and is intended as a curative treatment for laryngeal cancer, but it leaves the patient with no possibility to breathe, talk, and swallow normally anymore. A tracheostomy is created to restore breathing through the throat, but the aero-digestive tracts are permanently separated and the air no longer passes through the nasal tracts, which allowed filtration, warming, humidification, olfaction, and acceleration of the air for better tissue oxygenation. As for phonation restoration, various techniques allow the patient to talk again. The main one consists of a tracheo-esophageal valve prosthesis that makes the air passes from the esophagus to the pharynx, and makes the air vibrate to allow speech through articulation. Finally, swallowing is possible through the original tract as it is now isolated from the trachea. Yet, many methods exist to detect and assess a swallowing, but none is intended as a definitive restoration technique of the natural airway, which would permanently close the tracheostomy and avoid its adverse effects. In addition, these methods are non-invasive and lack detection accuracy. The feasibility of an effective early detection of swallowing would allow to further develop an implantable active artificial larynx and therefore restore the aero-digestive tracts. A previous attempt has been made on an artificial larynx implanted in 2012, but no active detection was included and the system was completely mechanic. This led to residues in the airway because of the imperfect sealing of the mechanism. An active swallowing detection coupled with indwelling measurements would thus likely add a significant reliability on such a system as it would allow to actively close an artificial larynx. So, after a brief explanation of the swallowing mechanism, this survey intends to first provide a detailed consideration of the anatomical region involved in swallowing, with a detection perspective. Second, the swallowing mechanism following total laryngectomy surgery is detailed. Third, the current non-invasive swallowing detection technique and their limitations are discussed. Finally, the previous points are explored with regard to the inherent requirements for the feasibility of an effective swallowing detection for an artificial larynx. Graphical Abstract.

Directed Functional Coordination Analysis of Swallowing Muscles in Healthy and Dysphagic Subjects by Surface Electromyography

Swallowing is a complex sequence of highly regulated and coordinated skeletal and smooth muscle activity. Previous studies have attempted to determine the temporal relationship between the muscles to establish the activation sequence pattern, assessing functional muscle coordination with cross-correlation or coherence, which is seriously impaired by volume conduction. In the present work, we used conditional Granger causality from surface electromyography signals to analyse the directed functional coordination between different swallowing muscles in both healthy and dysphagic subjects ingesting saliva, water, and yoghurt boluses. In healthy individuals, both bilateral and ipsilateral muscles showed higher coupling strength than contralateral muscles. We also found a dominant downward direction in ipsilateral supra and infrahyoid muscles. In dysphagic subjects, we found a significantly higher right-to-left infrahyoid, right ipsilateral infra-to-suprahyoid, and left ipsilateral supra-to-infrahyoid interactions, in addition to significant differences in the left ipsilateral muscles between bolus types. Our results suggest that the functional coordination analysis of swallowing muscles contains relevant information on the swallowing process and possible dysfunctions associated with dysphagia, indicating that it could potentially be used to assess the progress of the disease or the effectiveness of rehabilitation therapies.

Submental Muscle Activity and Its Role in Diagnosing Sarcopenic Dysphagia

PURPOSE

The objectives of this study were two-fold: 1) to investigate differences in activity duration and amplitude of the submental muscles during swallowing measured with surface electromyography (sEMG) in older patients with sarcopenic dysphagia compared to those without dysphagia and 2) to examine the diagnostic accuracy of submental sEMG signals for sarcopenic dysphagia.

PATIENTS AND METHODS

Patients (n = 60) aged ≥65 years participated in this cross-sectional study. The submental muscle activity duration parameters were the duration from the onset of swallowing to the maximum amplitude (duration A), duration from the maximum amplitude to the end of the swallowing activity (duration B), and total duration. The amplitude parameters were mean and maximum amplitude. Maximum lingual pressures were also measured for comparison with sEMG parameters.

RESULTS

Duration A was not significantly different between the groups (p = 0.15), but duration B (p < 0.001) and total duration (p < 0.001) were significantly different between the non-dysphagic and sarcopenic dysphagic groups. The mean (p = 0.014) and maximum (p < 0.001) amplitudes were significantly different between the groups. The area under the receiver operating characteristic curve (AUC) was 0.94 (95% confidence interval (CI) 0.87-0.98) for duration B, 0.95 (95% CI 0.89-0.99) for total duration, 0.76 (95% CI 0.63-0.87) for maximum amplitude, and 0.61 (95% CI 0.47-0.75) for mean amplitude. The AUC of the total duration was significantly greater than that of lingual pressure (p = 0.02).

CONCLUSION

Patients with sarcopenic dysphagia had longer submental muscle activity duration and higher amplitude during swallowing as assessed using sEMG. The findings of this study can be useful in elucidating the underlying pathophysiology of sarcopenic dysphagia and in diagnosing sarcopenic dysphagia.

Comparison of Pharyngoesophageal Segment Biomechanics Between Persons with Total Laryngectomy With and Without Dysphagia Using sEMG: A Multicentric Swallow Study

Total laryngectomy (TL) is the surgical treatment option for advanced stage of laryngeal cancer, involving the removal of larynx along with several muscles attached to it. Several anatomical changes occur following the surgery which will in turn affect the swallowing mechanism. The severing of the cricopharyngeus muscle, which is an important muscle of the pharyngoesophageal segment (PES), may lead to dysphagia. Several other causes have also been explained in the literature. Several invasive instruments have been used to identify dysphagia in this population. The present study aimed to identify the differences in the biomechanics of the PES during dry and wet swallow tasks in persons with TL with and without dysphagia. Amplitude and duration of movement of PES was analysed using a non-invasive instrumental method surface electromyography. The results indicate that amplitude of PES movement was significantly higher in dysphagic group for solids and semisolids. A significantly longer duration was observed for solid consistency for dysphagic group when compared to non-dysphagic group. sEMG evidences suggestive of differences in amplitude and duration between the TL with and without dysphagia groups. Findings also revealed that TL with dysphagia group require more effort to swallow solids and semisolid consistencies when compared to the effort exerted by them during liquid and dry swallow.

Posture-Dependent Dysphagia After Botulinum Toxin Type A Injection at Sternocleidomastoid in a Patient With Athetoid Cerebral Palsy

Cervical dystonia is a common issue in patients with athetoid cerebral palsy. Botulinum toxin injection to dystonic cervical muscles is a well-recognized treatment option, but it is known to be associated with dysphagia. Previously reported cases of dysphagia after botulinum toxin injection to the sternocleidomastoid muscle were related to the regional spread of toxin to the pharyngeal muscles. We report a unique case of posture-dependent dysphagia due to preactivation of the suprahyoid and infrahyoid muscles to compensate for impaired head stabilization by the weakened sternocleidomastoid muscle while swallowing. This case suggests a possible mechanism of dysphagia in patients with athetoid cerebral palsy.

Using Muscle Synergy to Evaluate the Neck Muscular Activities during Normal Swallowing

Swallowing is an extremely complex motion controlled by multiple muscles on the front neck region. Normal swallowing is dependent on orderly activation and co-coordination of the associated neck muscles, known as muscle synergy. However, evidence for muscle synergy during normal swallowing is rarely investigated. In this study, we studied the muscle synergy associated with swallowing saliva based on high-density (HD) surface electromyography (sEMG) signals acquired from four healthy subjects. The non-negative matrix factorization algorithm was applied to reconstruct the muscle activation patterns, and the values of variance accounted for (VAF) coefficients were computed to determine the number of muscle synergies. The results showed that the VAF values raised with the increase in the number of synergies on both the left and right sides of the neck. And the variation tendency of the VAF values was almost similar between the left and right area with a significant correlation ($\text{r}=0.9902 \pm 0.0046$, $\mathrm {p}<0.05)$. Furthermore, it was observed that an average of 5 muscle synergies was the minimum number required to sufficiently reconstruct the spatial characteristics of the synergism between both sides of the neck. These results suggest that the muscle synergy approach could serve as a promising candidate to evaluate the muscular co-contractions during swallowing, and it might be a useful method for dysphagia monitoring and diagnoses.

Swallowing and Temporomandibular Disorders in Adults

INTRODUCTION

Temporomandibular disease (TMD) etiology is multifactorial and is related to many perpetuating, predisposing, and initiating factors. The daytime parafunctions may have an important role in TMD pathogenesis. The most frequent parafunctions analyzed were the static parafunction (ie, clenching) and the dynamic parafunction (ie, grinding). In the present paper, the authors evaluated the swallowing (an oral function/parafunction) with the surface electromyography in patients with TMD.

MATERIALS AND METHODS

Twenty patients with TMD problems (nonhealthy patients, NHP) (mean age: 33 ± 1.994; 8 men and 12 women) and 20 healthy matched subjects (HP) (34.4 ± 2.782; 6 men and 14 women) were selected and examined. On each patient, an 8-channel surface electromyography was done during saliva swallowing.

RESULTS

Nonhealthy patients presented higher masseter and temporalis activation (P < 0.05) and an unbalancing of temporalis and submental muscles activation (P < 0.05) than the HP.

DISCUSSION

Nonhealthy patients presented a time of swallow higher than HP (P < 0.001). Nonhealthy patients presented a higher muscles activation and time of swallow than HP and a decrease of muscles balancing activation.

Non-neuronal evoked and spontaneous hemodynamic changes in the anterior temporal region of the human head may lead to misinterpretations of functional near-infrared spectroscopy signals

Several functional near-infrared spectroscopy (fNIRS) studies report their findings based on changes of a single chromophore, usually concentration changes of oxygenated hemoglobin ([[Formula: see text]]) or deoxygenated hemoglobin (HHb). However, influence of physiological actions may differ depending on which element is considered and the assumption that the chosen measure correlates with the neural response of interest might not hold. By assessing the correlation between [[Formula: see text]] and [HHb] in task-evoked activity as well as resting-state data, we identified a spatial dependency of non-neuronal hemodynamic changes in the anterior temporal region of the human head. Our findings support the importance of reporting and discussing fNIRS outcomes obtained with both chromophores ([[Formula: see text]] and [HHb]), in particular, for studies concerning the anterior temporal region of the human head. This practice should help to achieve a physiologically correct interpretation of the results when no measurements with short-distance channels are available while employing continuous-wave fNIRS systems.

Identification of the most significant electrode positions in electromyographic evaluation of swallowing-related movements in humans

Surface electromyography (sEMG) is a well-established procedure for recording swallowing-related muscle activities. Because the use of a large number of sEMG channels is time consuming and technically sophisticated, the aim of this study was to identify the most significant electrode positions associated with oropharyngeal swallowing activities. Healthy subjects (N = 16) were tested with a total of 42 channels placed in M. masseter, M. orbicularis oris, submental and paralaryngeal regions. Each test subject swallowed 10 ml of water five times. After having identified 16 optimal electrode positions, that is, positions with the strongest signals quantified by the highest integral values, differences to 26 other ones were determined by a Mann-Whitney U test. Kruskal-Wallis H test was utilized for the analysis of differences between single subjects, subject subgroups, and single electrode positions. Factors associated with sEMG signals were examined in a linear regression. Sixteen electrode positions were chosen by a simple ranking of integral values. These positions delivered significantly higher signals than the other 26 positions. Differences between single electrode positions and between test subjects were also significant. Sixteen most significant positions were identified which represent swallowing-related muscle potentials in healthy subjects.

Effect of submental sensitive transcutaneous electrical stimulation on virtual lesions of the oropharyngeal cortex

OBJECTIVE

The aim of this study was to assess the effect of submental sensitive transcutaneous electrical stimulation (SSTES) on pharyngeal cortical representation after the creation of an oropharyngeal cortical virtual lesion in healthy subjects.

METHODS

Motor-evoked potential amplitude of the mylohyoid muscles was measured with transcranial magnetic stimulation (TMS), the oropharyngeal cortex was mapped by cartography, and videofluoroscopic parameters of swallowing function were measured before and after SSTES (at the end of SSTES [0 min] and at 30 and 60 min), after the creation of a cortical virtual lesion (repetitive TMS, 1 Hz, 20 min on the dominant swallowing hemisphere).

RESULTS

Nine subjects completed the study. After 20 min of SSTES, motor-evoked potential amplitude increased (P<0.05), as did swallow reaction time after repetitive TMS, as seen on videofluoroscopy, which was reversed after electrical stimulation. On cortical mapping, the number of points with a cortical response increased in the dominant lesioned hemisphere (P<0.05), remaining constant at 60 min (P<0.05).

CONCLUSION

SSTES may be effective for producing cortical plasticity for mylohyoid muscles and reverses oropharyngeal cortical inhibition in healthy subjects. It could be a simple non-invasive way to treat post-stroke dysphagia.

Does orthodontic treatment provide a real functional improvement? a case control study

Background

Electromyographic analysis of the masticatory muscles provides useful data on the behavior of these muscles during stomatognathic system functioning and allows a functional assessment of orthodontic treatments. This study was undertaken to verify if achieving an Angle Class I bite through orthodontic treatment can lead to neuromuscular balance.

Methods

This study enrolled 30 patients (20 females, 10 males, mean age: 15.78 years) with an Angle Class II, division 1 malocclusion that was orthodontically treated. A group of 30 subjects (19 females, 11 males; mean age: 16.15 years), randomly selected among subjects with an Angle Class II, division 1 malocclusion that had not been orthodontically treated served as the Control group. Both groups were subjected to electromyography to study their neuromuscular characteristics. The Shapiro-Wilk's test revealed a non normal distribution, therefore we used a Friedman two way ANOVA by ranks test to compare differences of surface electromyography values between treated and untreated subjects at closed and open eyes condition.

Results

A statistically significant interaction between orthodontic treatment and open eyes conditions was detected for anterior temporal muscles. A significant imbalance of the anterior temporal muscles, which is indicative of an asymmetric electromyographic pattern, was also found.

Conclusions

The present data indicate that achieving a correct occlusal target does not necessarily correspond to a neuromuscular balance.

Surface electromyograph activity of submental muscles during swallowing and expiratory muscle training tasks in Huntington's disease patients

INTRODUCTION

Huntington's disease (HD) patients have difficulty in swallowing, leading to aspiration pneumonia, which is a major cause of death. It seems possible that submental muscles that are crucial for preventing an escape of a bolus into the airway, are affected by HD, but no previous studies have investigated this.

OBJECTIVE

To assess surface electromyograph (sEMG) activity of submental muscles during swallowing and expiratory muscle training (EMT) tasks in HD patients in comparison to healthy volunteers.

METHODS

sEMG activities of submental muscles during saliva, water swallowing, EMT tasks performed at 25% and 75% of maximum expiratory pressure were recorded and normalised by the sEMG activity during an effortful swallow in 17 early to mid stage HD patients and 17 healthy volunteers.

RESULTS

sEMG activity was greater (p<0.05) during EMT tasks than saliva and water swallowing, but was not significantly different between groups for saliva, water swallowing and EMT at 25%. HD patients had lower sEMG activity for EMT at 75% (p<0.05).

CONCLUSION

Decreases in submental muscle activity were not evident in HD patients except during EMT at 75%. This suggests that relative submental muscle weakness is observed only during a high intensity task in early to mid stage HD patients.

Mastigação e deglutição em mulheres jovens com desordem temporomandibular

OBJETIVO: Avaliar a mastigação e a deglutição em mulheres com e sem desordem temporomandibular (DTM) e investigar a posição da mandíbula e do osso hioide, por serem estruturas importantes para a realização destas funções. MÉTODOS: Setenta mulheres foram avaliadas quanto à presença de DTM segundo o instrumento Critérios de Diagnóstico para Pesquisa de Desordem Temporomandibular, sendo que 34 delas, com DTM, constituíram o grupo de estudo (GE) e 36 participaram do grupo controle (GC). A avaliação da mastigação e deglutição foi baseada no Protocolo de Avaliação Miofuncional Orofacial com Escores (AMIOFE). As variáveis referentes à posição da mandíbula e osso hioide aferidas pela análise cefalométrica. RESULTADOS: Os indivíduos com DTM apresentaram diferença significativa quanto à postura de língua (p=0,03) e lábios (p=0,04) durante a função de deglutição, bem como a adoção mais frequente de um padrão mastigatório unilateral crônico (p=0,03). Além disso, apresentaram posição mais baixa do osso hioide em relação à mandíbula (p=0,00). CONCLUSÃO: A presença de DTM promoveu maior frequência de alterações miofuncionais orofaciais durante as funções de mastigação e deglutição. A maior distância entre o osso hioide e a mandíbula, bem como a presença da sintomatologia álgica, podem justificar, em parte, os comportamentos atípicos da língua e dos lábios observados no grupo com DTM. A repercussão da DTM sobre as funções alimentares em uma faixa etária jovem explica a importância do diagnóstico e da intervenção terapêutica precoce nestes indivíduos.

Comparison between sensory and motor transcutaneous electrical nervous stimulation on electromyographic and kinesiographic activity of patients with temporomandibular disorder: a controlled clinical trial

Background

The purpose of the present controlled clinical trial was to assess the effect of a single 60 min application of transcutaneous electrical nervous stimulation (TENS) at sensory stimulation threshold (STS), compared to the application of motor stimulation threshold (MTS) as well as to untreatment, on the surface electromyographic (sEMG) and kinesiographic activity of patients with tempormanbibular disorder (TMD).

Methods

Sixty female subjects, selected according to the inclusion/exclusion criteria, suffering from unilateral TMD in remission were assigned to MTS, STS or untreatment. Pre- and post-treatment differences in the sEMG activity of temporalis anterior (TA), masseter (MM), digastric (DA) and sternocleidomastoid muscles (SCM), as well in the interocclusal distance (ID), within group were tested using the Wilcoxon test, while differences among groups were assessed by Kruskal-Wallis test; the level of significance was set at p ≤ 0.05.

Results

Significant pre- and post-treatment differences were observed in MTS and STS groups, for TA and MM of both sides; no significant difference was detected between MTS and STS groups. Kinesiographic results showed that the vertical component of ID was significantly increased after TENS in MTS and STS groups.

Conclusions

STS TENS could be effective, as well as MTS, in reduce the sEMG activity of masticatory muscles and to improve the ID of TMD patients in remission. Future studies are needed to confirm the results of the present study. Clinical relevance. The present study demonstrates that the application of TENS is effective in reduce the sEMG activity, as well as in increasing the ID of patients with TMD; our study did not support superior effectiveness of MTS or STS.

Trial registration

ClinicalTrials.gov: NCT01832207

Relationship between Class III malocclusion and hyoid bone displacement during swallowing: a cine-magnetic resonance imaging study

Objective

The displacement of the hyoid bone (HB) is a critical biomechanical component of the swallowing function. The aim of this study was to evaluate the swallowing-induced vertical and horizontal displacements of the HB in subjects with 2 different magnitudes of skeletal Class III malocclusion, by means of real-time, balanced turbo-field-echo (B-TFE) cine-magnetic resonance imaging.

Methods

The study population comprised 19 patients with mild skeletal Class III malocclusion, 16 with severe skeletal Class III malocclusion, and 20 with a skeletal Class I relationship. Before the commencement of the study, all subjects underwent cephalometric analysis to identify the nature of skeletal malformations. B-TFE images were obtained for the 4 consecutive stages of deglutition as each patient swallowed 10 mL of water, and the vertical and horizontal displacements of the HB were measured at each stage.

Results

At all stages of swallowing, the vertical position of the HB in the severe Class III malocclusion group was significantly lower than those in the mild Class III and Class I malocclusion groups. Similarly, the horizontal displacement of the HB was found to be significantly associated with the severity of malocclusion, i.e., the degree of Class III malocclusion, while the amount of anterior displacement of the HB decreased with an increase in the severity of the Class III deformity.

Conclusions

Our findings indicate the existence of a relationship between the magnitude of Class III malocclusion and HB displacement during swallowing.

Effect of complete denture wearing on deglutition time: a cine-magnetic resonance imaging study

Purpose of the study was to evaluate the effect of complete denture wearing on deglutition time (DT), hyoid bone and larynx movements in edentulous patients with real-time balanced turbo field echo cine-magnetic resonance imaging. Subjects were examined by cine-magnetic resonance imaging in supine position during swallowing water. Two sets of images for 23 edentulous (with/without wearing complete dentures) and one for 23 dentulous patients were obtained. Radiographic outputs representing three consecutive deglutition stages (oral, pharyngeal and oesophageal) were provided to perform measurements. Deglutition time significantly increased when edentulous patients wore their dentures (mean 0·75 s increased to 1·17 s), whereas dentulous patients' DT was about 0·91 s (P ≤ 0.05). The duration of deglutition is crucial because prolonged pharyngeal transit times increases the risk of aspiration. Within the limitations of the study, complete denture wearing could increase the shortened DT of the edentulous patients.

Effect of ill-fitting dentures on the swallowing duration in patients using polygraphy

BACKGROUND

Surface electromyography (SEMG) has been widely used in the recent years to study swallowing physiology, offering a valid and reliable tool for identifying normal swallowing. The goal of our study was to assess the contribution of denture fitness in the age-related increase of swallowing duration.

METHODS

Twenty denture wearers and 20 dentate individuals were analysed using SEMG and a computerised kinesiography of mandibular movement. Three spontaneous saliva swallowings were recorded for each patient with both their old and new prostheses. Three spontaneous saliva swallowings were recorded for each dentate person in two different recording sessions.

RESULTS

Old prosthesis mean swallowing time was 1.84 (SD ± 0.85) seconds while the new well-fitting prostheses needed a 1.28 (SD ± 0.55) (p = 0.0009) swallowing time. The difference in swallowing time was significant (p = 0.01) between dentate subjects and individuals wearing an old prosthesis. No significant difference was found between dentate subjects and the same prosthesis wearers when a new well-fitting prosthesis was worn.

CONCLUSION

Data presented in this work suggest that part of the increased duration of swallowing showed by elderly and healthy people is because of incorrect an dental prosthesis. Prolongation of swallowing duration in the elderly population could be reconsidered in the light of the quality of dental device worn by the aged population.

Atividade elétrica do músculo masseter durante a deglutição de líquido em adultos jovens

OBJETIVO: Caracterizar a atividade elétrica muscular do masseter durante a deglutição de líquido em indivíduos adultos jovens saudáveis. MÉTODOS: A população constou de 14 voluntários considerados saudáveis seguindo os critérios de inclusão e exclusão estabelecidos para esta pesquisa. Foi realizada avaliação eletromiográfica do músculo masseter bilateralmente, durante o repouso e nas tarefas de deglutição de 14,5 ml, 20 ml e 100 ml de líquido. O sinal eletromiográfico foi normalizado pela máxima atividade voluntária resistida (MAVR), considerada como 100% de atividade elétrica muscular. RESULTADOS: No masseter direito, a maior média percentual foi encontrada na tarefa de deglutição de 20 ml e no masseter esquerdo na tarefa de 14,5 ml. No masseter direito ocorreu diferença entre as deglutições de 14,5 ml e 20 ml. No masseter esquerdo não houve diferença entre as tarefas de deglutição. CONCLUSÃO: A atividade elétrica muscular do masseter em adultos jovens saudáveis durante a deglutição de líquido pode ser influenciada pelo volume deglutido e apresenta diferentes respostas bilateralmente.