Electromyographic evaluation of mastication and swallowing in elderly individuals with mandibular fixed implant-supported prostheses

The impacts of prosthetic interventions on mastication predominance in Kennedy Class Ⅱ patients

Purpose The purpose of this study was to investigate the effects of prosthetic interventions in patients with Kennedy Class Ⅱ (unilateral missing posterior teeth) on mastication predominance.Methods The subjects comprised patients with Kennedy Class II and healthy dentate volunteers (HD group). The subjects were asked to freely chew the test foods (chewing gum, beef jerky, and peanuts). Electromyographic activity of the bilateral masseter muscles was recorded twice (before and after prosthetic intervention). The chewing side (right or left) was judged by the level of the root mean square electromyographic amplitude. Mastication predominance was assessed using the mastication predominance index (MPI; range 0-100%). Each patient was restored with a removable partial denture (RPD) or an implant-supported fixed prosthesis (IFP). The effects of prosthetic interventions were statistically evaluated by the differences between MPI before and after prosthetic interventions (pre-MPI and post-MPI , respectively).Results There was a significant difference between pre-MPI of patients with Kennedy Class II and MPI of the HD group (HD-MPI) for all test foods (P < 0.0001). Statistical analysis also demonstrated a significant difference between pre-MPI and post-MPI measured with each of the three food items in both the RPD and IFP groups (P < 0.0001). Multiple comparisons revealed that post-MPI in the IFP group, but not in the RPD group, was statistically comparable with HD-MPI, although there were no significant differences among the three groups when MPIs were calculated using peanuts.Conclusions Prosthetic interventions improved mastication predominance in patients with Kennedy Class Ⅱ patients. Depending on the food type, IFP might contribute to better improvement of mastication predominance than RPD depending on food.

A High Masticatory Muscle Tone Predicts the Risk of Malnutrition and Frailty in Inpatient Older Adults: A Cross-Sectional Study

INTRODUCTION

The prevalence of malnutrition among inpatient older adults is as high as 20∼50%. Masticatory performance is known to affect the nutritional status of individuals. However, an objective measurement to reflect the real status of masticatory muscle performance is lacking at the bedside.

METHODS

This pilot study analyzed the masticatory performance using surface electromyography (sEMG) of masticatory muscles that measures both muscle strength and muscle tone at the bedside. The nutritional status was measured using the Mini Nutritional Assessment tool. The handgrip strength was measured using a hand dynamometer. The statistical data were analyzed using SPSS 25 software.

RESULTS

The data revealed that female inpatient older adults more frequently had substandard handgrip strength (p = 0.028), an at-risk and poor nutritional status (p = 0.005), and a higher masseter muscle tone (p = 0.024). Inpatient older adults with an at-risk and poor nutritional status had an older age (p = 0.016), lower handgrip strength (p = 0.001), and higher average masseter muscle tone (p = 0.01). A high masseter muscle tone predicted the risk of having an at-risk and poor nutritional status. The at-risk or poor nutritional status predicted having a substandard handgrip strength by 5-fold.

CONCLUSIONS

A high masticatory muscle tone predicts malnutrition and frailty. Medical professionals should combat masticatory dysfunction-induced malnutrition by detecting masticatory muscle performance using sEMG and referring patients to dental professionals. Additionally, encouraging inpatient older adults to perform oral motor exercise is recommended.

A Prospective Comparative Study of Mastication Predominance and Masticatory Performance in Kennedy Class I Patients

Mastication predominance in Kennedy class I (KC I) patients has not been well defined. This study aimed to investigate mastication predominance and masticatory performance in KC I patients, including the significance of remaining posterior teeth and removable partial-denture (RPD) treatment. KC I patients who had differences in the number of posterior teeth between left and right sides (D+) and KC I patients who had no differences (D−) were enrolled. Healthy dentate (HD) subjects were also registered as a positive control. Mastication predominance, defined by mastication predominance index (MPI; range 0–100%) calculated from electromyogram activities during voluntary chewing, and masticatory performance were evaluated at pre- and post-RPD treatment. Pre-MPI in KC I D+ was significantly higher than in HD. RPD treatment could significantly improve MPI and masticatory performance in both KC I groups. However, there were significant differences in masticatory performance between each KC I group and HD, regardless of RPD treatment. It was considered that the mastication predominance in KC I patients was affected by the difference in the number of remaining posterior teeth. RPD treatment could improve mastication predominance and masticatory performance in KC I patients, although the latter was not similar to HD group.

Effects of rehabilitation with complete dentures on bite force and electromyography of jaw and neck muscles and the correlation with occlusal vertical dimension

OBJECTIVES

The purpose of this study was to assess the effects of oral rehabilitation with complete dentures on bite force and electromyography of the suprahyoid and sternocleidomastoid muscles, and their correlation with occlusal vertical dimension (OVD). The research questions were "What are the effects of rehabilitation with complete dentures on bite force and electromyography of suprahyoid and sternocleidomastoid muscles, and how are they correlated with OVD?"

MATERIALS AND METHODS

Patients who are wearers of unsatisfactory removable complete dentures were attended in three sessions (T0, T1, and T2). At T0, while the patients still wore the old dentures, they were submitted to bite force and surface electromyographic exams of the suprahyoid and sternocleidomastoid muscles. These exams were repeated, and the OVD was measured while the patients wore their old and new prostheses, 30 days after insertion of the new prosthesis (T1). The exams were repeated 100 days after the insertion of the new prosthesis (T2). The data were submitted to the Shapiro-Wilk normality test, analysis of variance (ANOVA), and Pearson correlation and linear regression, all with 5% significance.

RESULTS

Fifteen patients participated in the study. No statistically significant difference was observed for bite force or electromyography in T0, T1, or T2. However, the correlation and regression tests showed important interactions between the OVD and maximum voluntary occlusal bite force, as well as the OVD and electromyography during deglutition for the suprahyoid muscles.

CONCLUSION

Rehabilitation did not impact bite force nor the activity of the assessed muscles (electromyography). On the other hand, OVD was shown to be an important factor for bite force, and deglutition of water after rehabilitation.

CLINICAL RELEVANCE

This study shows what are the influences of rehabilitation on oral functions and reinforces the importance of corrected reestablishment of OVD because it has been found to be an important factor for bite force and electromyography during deglutition.

A pseudo-mastication sound presentation device to improve the texture of nursing care foods

The texture of foods is affected by concurrent auditory sensations. To improve the texture of nursing care foods, we developed a pseudo-mastication sound presentation device based on electromyogram (EMG) signals from the muscles of mastication. EMG signals have enabled us to promptly present care recipients with pseudo-mastication sounds. However, actual mastication sounds vary in intensity and duration more than EMG signals. Here, we investigated changes in EMG signals and actual mastication sounds during the mastication of two food types (rice crackers and Japanese pickles) to improve our device. We found that the intensity and duration of mastication sounds decreased as the number of mastication strokes increased. Furthermore, the intensity and duration of mastication sounds and the latency between the onset of EMG signals and the onset of mastication sounds also varied by food type. For EMG signals, only the intensity varied by food type. Based on our findings, we modified our pseudo-mastication sound presentation device to enable control of the intensity and duration of pseudo-mastication sounds based on the number of mastication strokes and food type. Reproducing more natural pseudo-mastication sounds can improve care recipients' motivation for ingesting nursing care foods, thus preventing malnutrition and frailty.

ElectromyoFigureic Evaluation of Functional Adaptation of Patients with New Complete Dentures

Objective

The objective of this study was to evaluate the level of adaptation of patients to newly fitted complete dentures in their dominant and nondominant sides, by means of ElectromyoFigureic signals.

Materials and Methods

Eighty-eight patients with complete dentures were evaluated in the study. Masticatory muscle (masseter and temporal) bioelectric activity of the patients with complete dentures was recorded at maximum intercuspal relation. Parametric statistical data were analyzed with one-way repeated measures ANOVA test.

Results

Measurement time was significantly different for both dominant (DS) and nondominant (NDS) sides: FΣs-DS = 21.51, p=0.0001; FΣs-NDS = 13.25, p=0.0001. Gender was also significantly different: FΣs-DS-gender = 41.53, p=0.001; FΣs-NDS-gender = 85.76, p=0.0001. The average surface area values showed significant difference in females. Prior experience with dentures showed no significant difference for both sides of mastication: FΣs-DS-experiences = 1.83, p=0.1772; F Σs-NDS-experiences = 3.30, p=0.0697.

Conclusion

The planimetric indicators of bioelectric activity of masseter and temporalis muscles at maximum physiological loading conditions are significant discriminators of the level of functional adaptation of patients with new complete dentures.

Effects of mouth rehabilitation with removable complete dentures on stimulus perception and the electromyographic activity of the orbicularis oris muscle

STATEMENT OF PROBLEM

Many elderly individuals are rehabilitated with removable complete dentures, which require an initial adaptation period for both oral perception and the perioral muscles. Studies assessing the changes in stimulus perception and the electromyographic (EMG) activity of the orbicularis oris muscle shortly after conventional complete denture insertion are lacking.

PURPOSE

The purpose of this clinical study was to evaluate the effect of mouth rehabilitation with removable complete dentures on stimulus perception and the EMG activity of the orbicularis oris muscle.

MATERIAL AND METHODS

This study was approved by the Human Research Ethics Committee of the Araçatuba Dental School (São Paulo State University). Fifteen participants who had worn their removable complete dentures for at least 5 years and needed rehabilitation with new prostheses were enrolled in the study. A perception questionnaire was applied, and surface EMG examinations of the orbicularis oris muscle during rest, suction of water with a straw, and pronunciation of the syllables /bah/, /mah/, /pah/, and the word 'Mississippi' were performed before (T0) and 30 (T1) and 100 (T2) days after insertion of the new prostheses. The data were analyzed with the Cochran Q test, McNemar test, 2-way repeated measures ANOVA, and honestly significant difference (HSD) Tukey test (α=.05).

RESULTS

Significant improvement was reported in the perception questionnaire in terms of the oral discomfort sensation in the T2 period. EMG activity decreased during rest and suction after insertion of the new prostheses. A statistical difference between the upper and lower fascicles of the orbicularis oris muscle was detected, with a decrease of EMG activity between the T0 and T1 periods on the lower fascicle, except for when pronouncing the /pah/ syllable.

CONCLUSIONS

Mouth rehabilitation with removable complete dentures decreased oral discomfort and, depending on the oral function, decreased or increased EMG activity of the orbicularis oris muscle. In addition, the lower fascicle was more active than the upper fascicle during rest and most functional activities.

A influência de dentaduras implanto-suportadas sobre o estado nutricional de indivíduos idosos

RESUMO Objetivo: avaliar o estado nutricional de indivíduos idosos submetidos a procedimentos de reabilitação oral cirúrgico-protético. Métodos: foram avaliados 15 pacientes completamente edêntulos com idade igual ou superior a 60 anos (10 mulheres e 5 homens). Todos os indivíduos usaram prótese removível em ambos os arcos e tiveram suas próteses mandibulares substituídas por próteses com implante, foram submetidas à avaliação nutricional, compreendendo aspectos antropométricos, análise bioquímica do sangue e avaliação dietética antes da cirurgia e três e seis meses após a cirurgia. Resultados: a análise estatística da avaliação antropométrica não revelou diferença significativa entre os períodos de estudo, para todos os parâmetros investigados. A avaliação bioquímica revelou um aumento significativo da albumina três meses após o tratamento odontológico, voltando a níveis inferiores após seis meses. A avaliação dietética evidenciou que a ingestão calórica, macronutrientes proteínas e carboidratos não foram alterados após o tratamento odontológico. Por outro lado, a ingestão de lipídios foi menor seis meses após o tratamento odontológico em comparação com os resultados anteriores. Conclusão: portanto, a colocação de próteses dentárias completas implantadas nos idosos investigados neste estudo não modificou a condição nutricional no curto prazo, sugere que os sujeitos mantiveram as características alimentares anteriores.

Electromyography evaluation of masseter and temporalis, bite force, and quality of life in elderly patients during the adaptation of mandibular implant-supported overdentures

OBJECTIVES

The aim of this study was to investigate the outcomes of the installation of two implant-supported overdentures until such treatment is complete. Although this treatment is well established in the literature, there are no studies comparing what happens to muscles and the quality of life (QoL) of patients during the treatment.

METHODS

We selected 13 completely edentulous patients, according to inclusion and exclusion criteria, to rehabilitate with mandibular overdentures retained by two dental implants and a complete denture as antagonists. We evaluated the efficacy of the treatment and its evolution in five steps: (i) initially, with the old complete dentures, (ii) after the implants' placement with the mandibular prosthesis relined, (iii) after the placement of the healing abutments, (iv) after the installation and adaptation of new prostheses, and (v) after a 3-month follow-up period. At each stage, we evaluated patients via temporal and masseter electromyography (EMG), molar and incisive bite force, and QoL.

RESULTS

The results for EMG found a decrease in muscle activity during rest, the mastication of raisins, and lateral movements when the overdentures were installed. For the bite force and QoL, there was a gradual improvement from the placement of the healing abutments period (P ˂ 0.05), which was sustained until the follow-up.

CONCLUSIONS

Comfort and stability improved during the treatment, demonstrated by the QoL and bite force results. These results are positive for elderly patients who might refuse an implant-supported overdenture due to treatment length.

Influence of oral health condition on swallowing and oral intake level for patients affected by chronic stroke

BACKGROUND

According to the literature, the occurrence of dysphagia is high in cases of stroke, and its severity can be enhanced by loss of teeth and the use of poorly fitting prostheses.

OBJECTIVE

To verify that the status of oral health influences the level of oral intake and the degree of swallowing dysfunction in elderly patients with stroke in chronic phase.

METHODS

Thirty elderly individuals affected by stroke in chronic phase participated. All subjects underwent assessment of their oral condition, with classification from the Functional Oral Intake Scale (FOIS) and nasoendoscopic swallowing assessment to classify the degree of dysphagia. The statistical analysis examined a heterogeneous group (HG, n=30) and two groups designated by the affected body part, right (RHG, n=8) and left (LHG, n=11), excluding totally dentate or edentulous individuals without rehabilitation with more than one episode of stroke.

RESULTS

There was a negative correlation between the need for replacement prostheses and the FOIS scale for the HG (P=0.02) and RHG (P=0.01). Differences in FOIS between types of prostheses of the upper dental arch in the LHG (P=0.01) and lower dental arch in the RHG (P=0.04). A negative correlation was found between the number of teeth present and the degree of dysfunction in swallowing liquid in the LHG (P=0.05). There were differences in the performance in swallowing solids between individuals without prosthesis and those with partial prosthesis in the inferior dental arch (P=0.04) for the HG.

CONCLUSION

The need for replacement prostheses, type of prostheses, and the number of teeth of elderly patients poststroke in chronic phase showed an association with the level of oral intake and the degree of oropharyngeal dysphagia.

Conventional Versus Implant-Retained Overlay Dentures: A Pilot Study of Masseter and Anterior Temporalis Electromyography

Implant-supported overlay dentures (ISODs) have been widely accepted among patients using conventional removable complete dentures (CRCDs). The present study aimed to comparatively study conventional and ISODs in terms of function and coordination of masticatory muscles using electromyograms. Included were 10 patients with ISODs (each with 2 implants in the intercanine area). The mean wave range (MWR) and frequency (MWF) of masseter and temporalis were recorded with (ISOD) and without (CRCD) ball attachments while maximum clenching on cotton rolls (cotton roll clenching), maximum intercuspal clenching (clenching), and unilateral gum chewing (chewing) using electromyography. Data were analyzed in SPAW using t-paired for matched groups and independent-sample t tests for unmatched ones. The MWF differences were not statistically significant with or without attachments (P &gt; .05). Without attachments in place, the MWF of both masseter and temporalis muscles significantly decreased when patients clenched on cotton rolls (P = .01 and .02, respectively) and when chewing unilaterally (both P = .01). With attachments present, the right and left temporalis muscles did not show identical mean wave ranges while chewing (P = .01). Without attachments, this disharmony was seen in the left and right masseter muscles (P = .03). The MWR of masseter was higher in men while chewing with attachments (P = .02). Without attachments, the MWR of temporalis was higher in women while cotton roll clenching (P = .03) and chewing (P = .02). These findings are seemingly in favor of improved masticatory function and coordination in edentulous patients with the application of ISODs.

A eletromiografia de superfície nos periódicos nacionais em fonoaudiologia

TEMA: eletromiografia de superfície nos periódicos nacionais em Fonoaudiologia. OBJETIVO: caracterizar a abordagem da eletromiografia de superfície nos periódicos nacionais em Fonoaudiologia. CONCLUSÃO: poucos estudos abordam a eletromiografia de superfície nos periódicos nacionais em Fonoaudiologia, com maior concentração nas áreas de motricidade orofacial e fluência revelando uma maior necessidade de aprofundar esse assunto e diversificar os temas de interesse fonoaudiológico.