Relationship between ease of swallowing and deglutition‐related muscle activity in various postures

Summary The purpose of this study was to investigate the relationship between the ease of swallowing and the deglutition‐related muscle activity in various body and head postures by surface electromyography (EMG). Bipolar surface electrodes were placed on the right suprahyoid and infrahyoid muscles of nine healthy adults (19–28 years) while swallowing jelly. Ten postures per subject were examined: five body angulations (0° [supine], 30°, 60°, 90° [upright] and 120° from the horizontal) and two head positions (chin‐up and chin‐down). The duration and amplitude of suprahyoid and infrahyoid muscle activity were measured by an electromyograph, and the ease of swallowing was subjectively determined by using a rating scale (0 = difficult to swallow, 10 = easy to swallow). The group‐average duration and amplitude of muscle activity and the group‐average rating scales mostly showed insignificant changes with the body angulations independent of the head positions. Interestingly, the duration and amplitude of muscle activity during swallowing were negatively correlated with the rating scales, indicating that a shorter duration and smaller activity of muscle activity corresponds to easier swallowing. Consequently, the duration and amplitude of suprahyoid and infrahyoid muscle activity measured by surface EMG would be a useful indicator of the easy‐to‐swallow performance.     

Transcutaneous neuromuscular electrical stimulation can improve swallowing function in patients with dysphagia caused by non‐stroke diseases: a meta‐analysis

There is still debate over whether the effect of transcutaneous neuromuscular electrical stimulation (NMES) in dysphagia rehabilitation is superior to traditional therapy (TT). The purpose of this meta‐analysis was to assess the overall efficacy by comparing the two treatment protocols. Published medical studies in the English language were obtained by comprehensive searches of the Medline, Cochrane and EMBASE databases from January 1966 to December 2011. Studies that compared the efficacy of treatment and clinical outcomes of NMES versus TT in dysphagia rehabilitation were assessed. Two reviewers independently performed data extraction. Data assessing swallowing function improvement were extracted as scores on the Swallowing Function Scale as the change from baseline (change scores). Seven studies were eligible for inclusion, including 291 patients, 175 of whom received NMES and 116 of whom received TT. Of the seven studies, there were two randomised controlled trials, one multicentre randomised controlled trial and four clinical controlled trials. The change scores on the Swallowing Function Scale of patients with dysphagia treated with NMES were significantly higher compared with patients treated with TT [standardised mean difference (SMD) = 0·77, 95% confidence interval (CI): 0·13 to 1·41, P = 0·02]. However, subgroup analysis according to aetiology showed that there were no differences between NMES and TT in dysphagia post‐stroke (SMD = 0·78, 95% CI: ?0·22 to 1·78, P = 0·13, 4 studies, 175 patients). No studies reported complications of NMES. NMES is more effective for treatment of adult dysphagia patients of variable aetiologies than TT. However, in patients with dysphagia post‐stroke, the effectiveness was comparable.     

Effect of tongue position on masseter and temporalis electromyographic activity during swallowing and maximal voluntary clenching: a cross‐sectional study

The purpose of this study was to measure and compare the tonic electromyographic (EMG) activity of the temporalis and masseter muscles following placement of the tongue either on the palate or in the floor of the mouth during swallowing and maximal voluntary clenching (MVC). Thirty healthy dental students with natural dentition and bilateral molar support, between the ages of 18 and 22, with no prior history of oro‐facial injury, or current or past pain in the jaw, mouth or tongue participated in the study. Tonic masseter and temporalis EMG activities were recorded using surface electrodes. Subjects were instructed to passively place the tongue either on the anterior hard palate or in the floor of the mouth during swallowing and MVC. At each tongue position, the resulting EMG was recorded. During swallowing, no significant difference in EMG activity was found either for the masseter (P‐value = 0·1592) or the temporalis (P‐value = 0·0546) muscles, regardless of the tongue position. During MVC, there was a statistically significant difference for both the masseter (P‐value = 0·0016) and the temporalis (P‐value = 0·0277) muscles with lower levels recorded with the tongue in the floor of the mouth. This study found that in normal, pain‐free subjects, placing the tongue in the floor of the mouth significantly reduces masticatory muscle activity during MVC. Thus, it may be considered as a possible therapeutic option to decrease masticatory muscle activity; however, further research is needed in patients with oro‐facial pain.     

Inter‐ and intra‐rater reliability in fibroptic endoscopic evaluation of swallowing

Summary Fibroptic endoscopic evaluation of swallowing (FEES) is a useful way for dentists to evaluate oropharyngeal dysfunction. However, no study has paid attention to inter‐ and intra‐rater reliability of FEES evaluation about oropharyngeal dysfunction. The purpose of this study is to verify whether dentist who trained and experienced for evaluation of dysphagia could diagnose oropharyngeal function with FEES. Nine dentists independently evaluated FEES images of 10 cases four times each. At first, evaluators performed the first evaluation without consulting the evaluative criteria. Subsequently, evaluators independently re‐evaluated at 1‐week intervals for three consecutive weeks, consulting the evaluative criteria. And then, inter‐ and intra‐rater reliability was calculated. Cohen’s Kappa was used to assess reliability. The results found that overall inter‐rater reliability was 0·35 ± 0·04 (first evaluation), 0·45 ± 0·05 (s), 0·44±0·05 (third) and 0·46 ± 0·04 (fourth). Most of inter‐rater reliability related to aspiration was moderate to high, but lower for categories that evaluated timing of swallowing and mastication. In contrast, intra‐rater reliability was moderate to high for overall categories, at 0·53 ± 0·04 (first vs. second evaluation), 0·55 ± 0·04 (first vs. third), 0·53 ± 0·04 (first vs. fourth), 0·55 ± 0·03 (second vs. third), 0·60 ± 0·03 (second vs. fourth) and 0·78 ± 0·03 (third vs. fourth). FEES is reliable for experienced dentists to diagnose oropharyngeal function. Moreover, repeated evaluation with the aids of evaluative criteria is useful to improve the reliability of FEES.     

咬合支持丧失患者修复前后咀嚼肌表面肌电分析

目的：探讨咬合支持丧失患者修复前后咀嚼肌肌电的变化。方法：对24例咬合支持丧失患者进行常规修复,记录不同时期双侧咬肌和颞肌前束在下颌姿势位及牙尖交错紧咬位时的肌电活动,分析肌电幅值、不对称指数及咬肌/颞肌活动指数的变化。结果：（1）修复前后下颌姿势位肌电变化,咬肌肌电幅值和不对称指数在不同时期无明显变化（P〉0.05）;颞肌肌电幅值和不对称指数在义齿戴用3个月以上后显著小于义齿早期（P〈0.05）;咬肌/颞肌前束活动指数在各时期均小于0。（2）修复后牙尖交错位紧咬时肌电变化,咬肌及颞肌前束肌电幅值在戴牙3个月后显著高于戴牙早期（P〈0.05）;不对称指数与初戴牙时接近（P〉0.05）,较戴牙1周及1个月显著减小（P〈0.05）。咬肌/颞肌前束活动指数值在各时期均接近0。结论：咬合支持丧失患者进行咬合重建过程中,咀嚼肌肌电活动在不同时期有所变化。肌电测量可为咬合重建效果的评价提供参考。     

The effect of bolus volume on laryngeal closure and UES opening in swallowing: Kinematic analysis using 320‐row area detector CT study

This study investigated the effects of three different volumes of honey‐thick liquid on the temporal characteristics of swallowing. Twenty‐six healthy subjects (15 males, 11 females) underwent 320‐row area detector CT scan while swallowing 3, 10 and 20 mL of honey‐thick liquid barium. Three‐dimensional images were created at 10 images/s. Kinematic events involving six structures (velopharynx, hyoid bone, epiglottis, laryngeal vestibule (LV), true vocal cords (TVC), upper esophageal sphincter (UES)) and timing of bolus movement were timed using frame by frame analysis. The overall sequence of events did not differ across three volumes; however, increasing bolus volume significantly changed the onset and termination of events. The bolus head reached to pharynx and esophagus earlier and the duration of bolus passing through UES was significantly longer in 10 and 20 mL compared to 3 mL (P < .05). Consequently, the onset of UES opening was significantly earlier with increased volume (P < .05). LV and TVC closure occurred later in 20 mL compared to 3 mL (P < .05). These changes in motion of pharynx and larynx appeared to promote swallow safety by preventing aspiration, suggesting that anatomical structure movements adapt in response to bolus volume. Our findings also suggest that the pharyngeal swallow behaviours may be modified by afferents in the oral cavity. The three‐dimensional visualization and quantitative measurements provided by 320‐ADCT provide essential benchmarks for understanding swallowing, both normal and abnormal.     

Electromyographic analysis of masticatory and neck muscles in subjects with natural dentition, teeth-supported and implant-supported prostheses

Objectives: To compare the electromyographic (EMG) characteristics of masticatory and neck muscles in patients with natural dentition, teeth‐supported prostheses and implant‐supported prostheses. Materials and methods: Twenty‐five subjects aged 40–80 years were examined. Five patients had maxillary and mandibular implant‐supported fixed prostheses; five patients had mandibular implant‐supported fixed prosthesis and maxillary removable complete denture; seven patients had implant‐supported fixed prosthesis (one arch) and natural dentition or full‐arch tooth‐fixed prosthesis (one arch); and eight control subjects had natural dentition or single tooth‐fixed prostheses. Surface EMG of masseter, temporal and sternocleidomastoid muscles was performed during maximum teeth clenching and unilateral gum chewing. Interarch dental contacts were assessed with shim stocks. Results: All groups had similar interarch dental contacts (P>0.05). During clenching, patients with maxillary and mandibular implant‐supported fixed prostheses had unbalanced standardized masseter and temporalis anterior activities (74%), with significantly larger values found in the other patients and control subjects (all mean values larger than 86%, P=0.017). All patients chewed with significantly larger muscular potentials than control subjects (on average, 1434–2100 μV s vs. 980 μV s, P=0.04), and had altered muscular patterns (left side, P=0.021). The patients with one arch with natural dentition/tooth fixed prostheses had chewing muscular patterns similar to the control subjects. Conclusions: Clenching with the analyzed prostheses was performed with a relative increment of temporalis activity. Neuromuscular coordination during chewing was larger in patients who maintained their teeth or dental roots, independently from the number of dental contacts.     

Effects of exercise on swallowing and tongue strength in patients with oral and oropharyngeal cancer treated with primary radiotherapy with or without chemotherapy

Tongue strength is reduced in patients treated with chemoradiotherapy for oral/oropharyngeal cancer. Tongue strengthening protocols have resulted in improved lingual strength and swallowing in healthy individuals, as well as in patients following a neurological event. However, no studies have examined the efficacy of tongue strengthening exercises on tongue strength, swallowing, and quality of life (QOL; Head and Neck Cancer Inventory) in patients treated with chemoradiotherapy. A randomized clinical trial examined the effects of a tongue strengthening programme paired with traditional exercises vs. traditional exercises alone. Dependent variables included tongue strength, swallowing, and QOL in a group of patients with oral and oropharyngeal cancer treated with primary radiotherapy with or without chemotherapy. Differences with regard to tongue strength and oropharyngeal swallow efficiency (OPSE) were not observed within or between groups. QOL in the eating and speech domains improved following treatment in both groups. However, the experimental group demonstrated greater impairment in QOL in the social disruption domain following treatment, whereas the control group demonstrated a slight improvement in functioning. Tongue strengthening did not yield a statistically significant improvement in either tongue strength or swallowing measures in this patient cohort. Patient compliance and treatment timing may be factors underlying these outcomes.     

Self‐perceived oral symptoms and periodontal status among young intravenous heroin addicts: A cross‐sectional case‐control study

1 Background

It is hypothesized that (a) self‐perceived oral symptoms (OSs) are worse in intravenous heroin addicts (IHA) than controls; and (b) clinical periodontal inflammatory parameters (plaque index [PI], bleeding on probing [BOP], PD and clinical attachment loss [AL]), number of missing teeth (MT), and radiographic marginal bone loss (MBL) are higher in IHA compared with controls. The aim was to compare the self‐perceived OSs and periodontal parameters among young IHA and controls.

2 Methods

Sociodemographic data, self‐perceived OSs and duration and daily frequency of intravenous heroin use was gathered using a structured questionnaire. Full‐mouth PI, BOP, PD, and clinical AL were measured, and number of MT were recorded. Mesial and distal MBL on all teeth was measured on digital radiographs. Odds ratios (OR) with 95% confidence intervals (CI) were computed for self‐perceived OSs and periodontal parameters were assessed using the Mann Whitney U‐test and logistic regression analysis. Sample‐size was estimated, and level of significance was set at P < 0.05.

3 Results

OR (95% CI) for self‐perceived loose teeth (P < 0.001), pain in teeth (P < 0.001), dry mouth (P < 0.001), burning sensation in mouth (P < 0.001), bleeding gums (P < 0.001) and pain during chewing (P < 0.001) were significantly higher in the test than control group. Number of MT (P < 0.05), PI (P < 0.05), clinical AL (P < 0.05), and mesial (P < 0.05) and distal (P < 0.05) MBL were statistically significantly higher among individuals in the test group compared with the control group.

4 Conclusion

Self‐perceived OSs and periodontal inflammatory parameters were worse in IHA than controls.     

Periodontal status in oral mucous membrane pemphigoid: initial results of a case‐control study

Oral Diseases (2010) 17 , 90–94 Objective: To evaluate the periodontal status of mucous membrane pemphigoid (MMP) patients and compare it with that of healthy controls. Methods: A prospective study was undertaken to examine the impact of gingival MMP lesions on the human periodontium of 29 patients. Parameters evaluated included full mouth plaque score (FMPS), full mouth bleeding upon probing scores, probing depths (PD), gingival recession, clinical attachment level (CAL), mobility score, furcation involvement, number of missing teeth and Machtei criteria. Results: All periodontal parameters recorded were increased in cases when compared to controls in univariate statistics. The mean differences between groups in PD (0.8 ± 0.2 mm, 95% CI 0.3–1.3), CAL (1.3 ± 0.4 mm, 95% CI 0.4–2.2), FMPS (41.0 ± 6.2%, 95% CI 28.7–53.4), FMBS (16.2 ± 6.6%, 95% CI 3.0–29.4) and tooth loss (2 ± 1 teeth, 95% CI 1–3) were all statistically significant (P < 0.01 for all). Substantial differences in domiciliary oral hygiene routines were observed (P < 0.0001). In multivariate models when FMPS was included as covariate the difference between groups in all clinical periodontal parameters was no longer statistically significant. Conclusions: Our results showed that periodontal status is worse in MMP patients if compared with healthy controls due to a substantial difference in oral hygiene. Oral health should be promoted in MMP.     

Tongue‐to‐palate resistance training improves tongue strength and oropharyngeal swallowing function in subacute stroke survivors with dysphagia

Tongue function can affect both the oral and pharyngeal stages of the swallowing process, and proper tongue strength is vital for safe oropharyngeal swallowing. This trial investigated the effect of tongue‐to‐palate resistance training (TPRT) on tongue strength and oropharyngeal swallowing function in stroke with dysphagia patients. This trial was performed using a 4‐week, two‐group, pre–post‐design. Participants were allocated to the experimental group (n = 18) or the control group (n = 17). The experimental group performed TPRT for 4 weeks (5 days per week) and traditional dysphagia therapy, whereas the control group performed traditional dysphagia therapy on the same schedule. Tongue strength was measured using the Iowa Oral Performance Instrument. Swallowing function was measured using the videofluoroscopic dysphagia scale (VDS) and penetration–aspiration scale (PAS) based on a videofluoroscopic swallowing study. Experimental group showed more improved in the tongue strength (both anterior and posterior regions, P = 0·009, 0·015). In addition, the experimental group showed more improved scores on the oral and pharyngeal phase of VDS (P = 0·029, 0·007), but not on the PAS (P = 0·471), compared with the control group. This study demonstrated the effectiveness of TPRT in increasing tongue muscle strength and improving swallowing function in patients with post‐stroke dysphagia. Therefore, we recommend TPRT as an easy and simple rehabilitation strategy for improving swallowing in patients with dysphagia.