Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

When eating, mastication is always followed by swallowing. The present study assessed the effect of mastication on swallowing-related neural pathways in humans. Twenty healthy volunteers participated and underwent baseline transcranial magnetic stimulation to evaluate cortico-pharyngeal and cortico-hand motor-evoked potentials (MEPs). Next, they performed a chewing task and a swallowing task. Repeated-measures ANOVA revealed that pharyngeal MEPs were significantly higher after the swallowing task than after the chewing task, even though the number of swallows across tasks was matched. This implies that chewing movements suppress swallowing-related activity in the pharyngeal motor circuit.

DOI： 10.1016/j.physbeh.2022.113763

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Oral hypofunction is defined as the reversible stage preceding oral dysfunction. However, its assessment and management need further examination and consideration. OBJECTIVE: The present study aimed to examine the current state of oral hypofunction among outpatients at the university hospital. METHODS: New outpatients underwent medical interviews and detailed assessment of oral hypofunction at their initial visit to our dental department. Oral hypofunction was diagnosed if the results of three of the following seven assessment items were below cut-off values: poor oral hygiene, oral dryness, reduced occlusal force, decreased tongue-lip motor function, decreased tongue pressure, decreased masticatory function and deterioration of swallowing function. The relationships between factors used to diagnose oral hypofunction as well as the distributions of assessment values were clarified. RESULTS: Seventy-five of 209 patients (35.9%) were finally diagnosed with oral hypofunction. Diagnosis of oral hypofunction was significantly related to patient age, Eichner index, a chief complaint of dental or periodontal disease or ill-fitting dentures and a history of neurodegenerative disease. The lowest quintile values for poor oral hygiene, oral dryness and decreased masticatory performance were all above current cut-off values. Reduced occlusal force contributed strongly to the diagnosis of oral hypofunction. CONCLUSION: Oral hypofunction in dental outpatients at a university hospital was associated with patient age, medical history and chief complaint at presentation. Diagnosis of oral hypofunction can be closely related to reduced occlusal force. The validity of cut-off values for assessments of oral hypofunction needs further consideration.

DOI： 10.1111/joor.13237

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Thermal tactile oropharyngeal stimulation has been clinically used to facilitate swallowing initiation in dysphagic patients. We previously demonstrated that thermal stimulation applied to the oral cavity provokes an immediate excitability in pharyngeal motor cortex. The aim of the current study was to investigate whether thermal stimulation can produce longer lasting effects on the corticopharyngeal neural pathway. METHODS: Healthy volunteers (n = 8/12) underwent baseline pharyngeal motor evoked potential (PMEP) measurements evoked by transcranial magnetic stimulation. In the first experiment, subjects received thermal stimulation alternating 30 seconds of 15 and 36°C applied to the tongue surface for either 10 minutes, 5 minutes, or sham. In the second experiment, one of three intermittent thermal stimulus patterns was delivered: cold (alternating 30 seconds of 15 and 36°C), warm (continuous 36°C), or hot (alternating 30 seconds of 45 and 36°C) for 10 minutes. In both experiments, PMEP were remeasured every 15 minutes up to 60 minutes following thermal stimulation. KEY RESULTS: Repeated measures ANOVA for each stimulus time in the first experiment showed a significant increased change in PMEP amplitude at 30 minutes following only 10-minute stimulation compared with sham (P < .05). In the second experiment, we found that cold stimulation was more effective than the other stimulation (P < .05) at increasing PMEP amplitudes. CONCLUSIONS AND INFERENCES: Ten-minute cold stimulation on the tongue can induce a delayed (30 minutes) increase in pharyngeal cortical excitability, providing a clinically useful therapeutic window for its application in dysphagic patients.

DOI： 10.1111/nmo.13938

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

BACKGROUND: Tongue lift movement (TLM) is used as a therapy to improve tongue pressure against the hard palate for dysphagic patients. OBJECTIVE: The present study aimed to characterize the time-dependent endurance changes in hyoid muscle activity and hyoid-laryngeal displacement during TLM in different ways. METHODS: Sixteen young healthy volunteers were instructed to perform TLM at maximum effort (100%) against the anterior and posterior parts of the hard palate using a balloon-type tongue pressure instrument, followed by a 10-second recording during anterior 80% TLM, anterior 100% TLM, posterior 80% TLM and posterior 100% TLM with visual feedback. Electromyography (EMG) of suprahyoid (S-Hyo) and infrahyoid (I-Hyo) muscles and videofluorography were simultaneously recorded. To evaluate temporal changes, the recording period was divided into three substages: early, middle and late. Tongue pressure, integrated EMG (iEMG), power frequency of EMG burst and hyoid-laryngeal position were compared among the conditions (80% vs 100%, anterior vs posterior and early vs middle vs late). RESULTS: Tongue pressure was stably maintained for 10 seconds in all conditions. S-Hyo iEMG and I-Hyo iEMG were significantly greater at 100% than at 80%, while no significant difference was observed between positions. S-Hyo iEMG and I-Hyo iEMG significantly increased at the late stage, while power frequency of EMG burst gradually decreased. Significant temporal changes in laryngeal elevation were observed only in posterior 100% TLM. CONCLUSION: The current results suggested that isometric posterior TLM may be more useful compared with anterior TLM in clinical situations for dysphagic patients to elevate the hyolaryngeal complex.

DOI： 10.1111/joor.12988

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Authorship：Lead author,　Corresponding author   Language：English  

DOI： 10.1111/nmo.13384

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Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/nmo.12839

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BACKGROUND: Solid foods mix with saliva during mastication to form a bolus. The water content of the food bolus and lubrication in the oral cavity are critical factors that determine the dynamics of the masticatory muscles. Among other factors, fat is believed to affect masticatory behaviour by lubricating foods. OBJECTIVES: The effects of artificially induced hyposalivation on masticatory behaviour and bolus properties were investigated using bread with varying water content and spreads to evaluate how these properties affect masticatory behaviour with hyposalivation. METHODS: Twenty healthy volunteers were instructed to eat bread with and without spreads. Before and after atropine administration, electromyographic activity was recorded in the masseter, suprahyoid and infrahyoid muscles. Masticatory movements and bolus properties were compared between breads, oral cavity conditions and spreads. RESULTS: Hyposalivation directly affected mastication behaviour only for dry bread, with masticatory duration and cycle time, and suprahyoid muscle activity increasing. These effects were primarily observed during the middle and late stages of mastication, particularly in the absence of spreads. The effect of spreads was significant only on dry bread with hyposalivation, decreasing masticatory cycle time and masseter and suprahyoid activity at the middle-to-late stage. Hyposalivation decreased the water content and increased the hardness of the bolus in dry bread, both with and without spreads. CONCLUSION: Bolus formation and transport during the mastication of dry bread are interrupted by hyposalivation. The addition of spreads can compensate for the affected masticatory movements without significant changes in bolus properties.

DOI： 10.1111/joor.13987

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Publishing type：Research paper (scientific journal)   Publisher：American Physiological Society  

The swallowing reflex can be induced by peripheral stimulation of the larynx. Although previous studies have suggested that potassium ions exert facilitatory effects on the initiation of swallowing, little information is available on the mechanism underlying the potassium ion-evoked swallowing reflex. In this study, we evaluated the effects of potassium ions on peripheral afferent responses and the initiation of swallowing in conscious and anesthetized rats. Furthermore, the possible receptors involved were explored. The topical application of potassium chloride (KCl) significantly facilitated the swallowing reflex; these facilitatory effects were more prominent than those of distilled water (DW) or sodium chloride (NaCl). This phenomenon depended not on the concentrations of anions but on those of potassium ions. The potassium ion-induced response in the superior laryngeal nerve was most prominent after treatment with KCl, especially at the early stage. In chronic rats, without differences in licking behavior between DW, NaCl, and KCl, the intervals between swallows were the smallest during KCl-associated licking. Inward rectifier potassium channel (Kir)3.1- and Kir6.2-positive cells were detected in the nodose ganglion and vocal folds. The rate of expression of these molecules in immunoreactive cells was relatively high at 74.1% for Kir3.1 and 75.3% for Kir6.2. Kir3.1- and Kir6.2- blockers significantly decreased the number of KCl-induced swallows. Possible mechanisms underlying potassium ion-induced swallowing are discussed. Our findings suggest that Kir3.1 and Kir6.2 are involved in K ion-induced swallowing in rats.

DOI： 10.1152/ajpgi.00012.2025

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Background/Objective: The International Dysphagia Diet Standardisation Initiative (IDDSI) and the Japanese Dysphagia Diet 2021 (JDD2021) are prominent systems that classify thickened beverages for dysphagia management. We herein aim to establish a correspondence between these systems through systematic viscosity measurements. Methods: We analyzed 49 thickened beverage samples using an E-type viscometer, IDDSI flow test, and JDD syringe test. Results: Receiver operating characteristic analysis revealed the following viscosity cutoffs for IDDSI levels: 0-1 at 72.0 mPa·s (area under the curve [AUC] 0.94), 1-2 at 112.0 mPa·s (AUC 0.95), and 2-3 at 303.0 mPa·s (AUC 0.97). Multiple regression analysis revealed that beverage characteristics, including fat, sodium content, and settling time, significantly influenced viscosity (R2 = 0.803). The findings established that IDDSI Level 0 corresponds to a thinner viscosity than JDD Stage 1 and Stage 1 (0-72 mPa·s), Level 1 to Stage 1 (72-112 mPa·s), Level 2 to Stages 1-2 (112-303 mPa·s), and Level 3 to Stage 3 (>303 mPa·s). Moreover, the measurement methods had high correlations (r = 0.83-0.93, p < 0.001). Conclusions: The comprehensive map between IDDSI and JDD2021 classifications developed from the results of this study enables healthcare providers to translate between the classification systems, improving dysphagia management internationally while supporting evidence-based care and global research.

DOI： 10.3390/nu17061051

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Physiological Society  

The aim of this study was to clarify whether the posterior belly of the digastric (post-Dig) muscle is activated during the swallowing reflex and whether the post-Dig muscle is directly controlled by the swallowing central pattern generator (CPG) in anesthetized rats, using physiological and immunohistochemical approaches. In physiological study, electromyograms (EMGs) of the post-Dig, sternohyoid and thyrohyoid muscles, and the diaphragm were recorded during respiration and swallowing with and without airway stenosis. In the immunohistochemical study, c-Fos immunoreactivity for expression of cells during swallowing was analyzed. Motoneurons were identified using immunohistochemistry with Fluoro-gold (FG). EMG bursts were observed in the hyoid muscles during the inspiratory phase and swallowing. With airway stenosis, the swallowing EMG activity was facilitated in terms of duration and area only in the post-Dig muscle. The coordination of these EMG activities during swallowing was maintained with airway stenosis. In contrast, the offset of the post-Dig EMG burst was delayed with airway stenosis. c-Fos-positive cells were observed in the accessory facial nucleus (Acs7), but only in the rostral portion. FG-labeled cells were observed in Acs7. Several c-Fos/FG double-labeled cells were observed only in the rostral Acs7. These results suggested that the post-Dig muscle is activated during swallowing, the activation of which is controlled by the swallowing CPG, and that the distribution of Acs7 neurons, which innervate the post-Dig muscle, was uneven in the nucleus. In addition, the modulation of post-Dig muscle activity during inspiration might be due to changes in peripheral conditions via respiratory CPG.

DOI： 10.1152/ajpgi.00374.2024

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Frontiers Media SA  

Chronic obstructive pulmonary disease (COPD) was previously known as chronic bronchitis and emphysema. It has various main symptoms, such as dyspnea, chronic cough, and sputum, and is often accompanied by dysphagia. Although many published clinical reports have described COPD-related dysphagia, the physiological mechanisms underlying swallowing changes due to COPD remain unclear. Therefore, we analyzed how COPD affects the swallowing reflex using COPD model rats. We performed an electrophysiological study of respiration and swallowing using COPD model induced by intratracheal administration of porcine pancreatic elastase and lipopolysaccharide in Sprague-Dawley male rats. To identify the respiration and swallowing responses, electromyographic activity was recorded from the diaphragm, digastric (Dig), and thyrohyoid (TH) muscles. We confirmed COPD using micro-computed tomography analysis and hematoxylin and eosin staining of the lungs. The duty cycle was defined as the ratio of the inspiration duration to the total respiratory duration. In COPD model rats, the duty cycle was significantly higher than that in control rats. The frequency of the swallowing reflex evoked by electrical stimulation of the superior laryngeal nerve during the inspiration phase was higher in COPD model rats than in control rats. Furthermore, long-term COPD altered Dig and TH muscle activity without pathological muscle change. Our results suggest that COPD increases the frequency of swallowing initiation during the inspiration phase. Furthermore, long-term COPD affects swallowing-related muscle activity without pathological muscle changes. These physiological changes may increase the risk of developing dysphagia. Further studies are necessary to clarify the mechanisms contributing to the functional changes in respiration and swallowing in COPD.

DOI： 10.3389/fphys.2024.1445336

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The sternohyoid muscle depresses the hyoid bone, but it is unclear whether the muscle contributes to respiratory and swallowing mechanisms. This study aimed to clarify whether the sternohyoid muscle participates in the respiration and swallowing reflex and how the activity is modulated in two conditions: with airway stenosis and with a fixed sternohyoid muscle length. Electromyographic activity in the sternohyoid, digastric, thyrohyoid, and diaphragm muscles was recorded in anesthetized rats. The sternohyoid muscle activity was observed in the inspiratory phase and during swallowing, and was well coordinated with digastric and thyrohyoid muscle activity. With airway stenosis, the respiratory activity per respiratory cycle was facilitated in all assessed muscles but the facilitation of activity per second occurred only in the digastric, thyrohyoid, and sternohyoid muscles. With airway stenosis, the swallowing activity was facilitated only in the digastric muscle but not in the thyrohyoid and sternohyoid muscles. Swallowing activity was not observed in the sternohyoid muscle in the condition with the sternohyoid muscle length fixed, although increased inspiratory activity remained. The current results suggest that (1) the sternohyoid muscle is slightly activated in the inspiratory phase, (2) the effect of airway stenosis on respiratory function may differ between the upper airway muscles and diaphragm, and (3) swallowing activity in the sternohyoid muscle is not dominantly controlled by the swallowing central pattern generator but instead occurs as a myotatic reflex.

DOI： 10.1152/ajpgi.00138.2024

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BACKGROUND: It remains unclear how the salivary flow and the fat content of food affect bolus formation during mastication. OBJECTIVES: We aimed to clarify: (1) how hyposalivation affects jaw-closing and hyoid-elevating muscle activities in bolus formation, and (2) if the effect of hyposalivation on muscle activity depends on the fat content of food. METHODS: Eighteen healthy male volunteers were instructed to freely ingest four test foods: Plain, Fat without seasoning, Fat with seasoning, and Soft rice crackers. Masseter and suprahyoid electromyographic activities were recorded before and 30 min after the administration of atropine sulfate, a muscarinic receptor antagonist that induces hyposalivation. RESULTS: Hyposalivation extended the masticatory duration significantly in all the test foods except Fat with seasoning. Masticatory cycle time was significantly longer with vs without hyposalivation for the Soft (p = .011). Suprahyoid activity/cycle was significantly greater with vs without hyposalivation (p = .013). Masticatory cycle time was significantly longer at the late stage with vs without hyposalivation for the Soft (p < .001). Suprahyoid activity/cycle was significantly greater at the middle (p = .045) and late stages (p = .002) with vs without hyposalivation for the Soft and greater at the late stage with vs without hyposalivation for the Plain (p = .043). Changes in masticatory cycle time and suprahyoid activity/cycle for these foods had significantly positive relationship (p < .001). CONCLUSION: Hyposalivation-induced changes in masticatory behaviours resulted from the middle and late stage suprahyoid activity. Fat content and seasoning compensate for salivary flow inhibition.

DOI： 10.1111/joor.13764

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

Background

Modification of foods or liquids is commonly administered as part of dysphagia treatment. However, no consensus exists on the parameters for defining texture‐modified food for patients with dysphagia.

Objectives

The aim of this study was to evaluate the effect of food/liquid material on swallowing physiology in patients with dysphagia and to discuss the optimal food choice for direct swallowing therapy.

Materials and Methods

A total of 140 patients underwent a videofluoroscopic swallowing study using three test foods/liquids: 3 mL of mildly thick liquid (Thick liquid), jelly made of agar and polysaccharide (Jelly) and jelly made of pectin (Reset gel). Outcome measures of videofluoroscopic images, bolus transit time and hyoid movements were compared.

Results

The frequency of chewing movements was highest for Jelly, followed by Reset gel and Thick liquid. While the probability of oral residue was the highest for Reset gel, pharyngeal residue after swallowing was high for Thick liquid as compared to Jelly and Reset gel. Oral transit time and pharyngeal transit time for Thick liquid were significantly smaller than that for Jelly and Reset gel. Pharyngeal delay time was significantly smaller for Thick liquid than that for Jelly and Reset gel. There was no difference in hyoid elevation time and hyoid movement time among the conditions.

Conclusion

Mildly thick liquid material may be optimal for patients with primarily oral motor function impairment and jelly, such as Reset gel, may be more suitable for patients with primarily pharyngeal motor function impairment or oral and pharyngeal coordinative motor function decline.

DOI： 10.1111/joor.13709

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Mastication is controlled by central pattern generator in the brainstem and can be modulated by volition. The aim of this study was to investigate the effect of chewing well on swallowing. Twenty-six healthy participants were instructed to eat 8, 12, and/or 16 g of steamed rice with barium sulphate under the following two conditions: chewing freely task (CF; chewing naturally in their usual manner) and chewing well task (CW; chewing the food with a request to "chew well"). We evaluated bolus transport and swallowing movement using videofluoroscopy and electromyography of the masseter, suprahyoid and thyrohyoid muscles. The chewing time and pharyngeal transit time (PTT) at the first swallow showed high reproducibility in both CF and CW. PTT for CW was significantly shorter and longer than CF in 12 and 16 g, respectively. In 12 g, CW increased the pharyngeal bolus velocity and decreased thyrohyoid EMG activity during swallowing compared with CF. In 16 g, the difference between CW and CF in the estimated swallowed bolus volume was positively correlated with that in upper esophageal sphincter transit duration. We speculate that CW modulates PTT during swallowing depending on the mouthful volume.

DOI： 10.1007/s00455-024-10689-z

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Pharyngeal electrical stimulation (PES) applies electrical stimulation to pharyngeal mucosa (PhM) and represents a useful approach to improve swallowing function in patients with dysphagia. To determine the optimal PES modality to treat dysphagia, the mechanism underlying the effects of PES on swallowing function must be elucidated. In this study, we evaluated how PES and electrical stimulation of the superior laryngeal nerve (SLN) modulate the initiation of swallowing in anesthetized rats. A swallow was evoked by electrical stimulation of the PhM, SLN, and nucleus of the solitary tract (nTS) and pharyngeal mechanical stimulation using a von Frey filament. A swallow was identified by electromyographic bursts in mylohyoid and thyrohyoid muscles. Bilateral SLN transection abolished the swallows evoked by PhM electrical stimulation. PhM and SLN electrical stimulation decreased swallowing frequency in a similar time-dependent manner. Intravenous administration of the GABAA receptor antagonist bicuculine did not affect the time-dependent change in swallowing frequency during SLN electrical stimulation. Continuous SLN electrical stimulation significantly inhibited pharyngeal mechanically and nTS-electrically evoked swallows compared with before and 5 min after stimulation. The present findings suggest that the SLN plays a primary role in PES-evoked swallows. Additionally, continuous SLN electrical stimulation inhibits the initiation of swallowing, and the modulation of central network associated with swallowing might be partially involved in this inhibition.

DOI： 10.1016/j.neulet.2024.137672

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The external carotid artery (ECA) plays a major role in supplying blood to the head and neck. Although impeded blood flow in the ECA is expected to affect orofacial functions, few studies have shown how blood flow obstruction in the ECA contributes to impairment of these functions, including chewing and swallowing. This study was performed to investigate the effects of ECA ligation (ECAL) on immediate and long-term changes in masticatory and swallowing functions as well as the jaw-opening reflex evoked in the digastric muscle. The experiments were carried out using male Sprague-Dawley rats. In the acute experiment, the digastric reflex evoked by low-threshold electrical stimulation of the inferior alveolar nerve and the swallow reflex, identified by digastric and thyrohyoid electromyographic (EMG) bursts, were compared between before and 1 h after ECAL. The chronic experiment was conducted on freely moving rats. EMGs of the masseter, digastric, and thyrohyoid muscles were chronically recorded. The long-term effects of ECAL on behavior and muscle histology were compared between rats with an intact ECA and rats with ECAL. In the acute experiment, the peak amplitude of the digastric reflex on the ECAL side was significantly decreased 1 h after ECAL. In the chronic experiment, although most parameters of the masticatory and swallowing EMGs were not significantly different between the groups, the results suggest wide variation of the effect of ECAL on the muscles. Blood supply compensation from collaterals of the internal carotid artery may be permanent in some animals.NEW & NOTEWORTHY The inhibitory effect of unilateral external carotid artery ligation (ECAL) on the ipsilateral digastric reflex was small but evident. Most parameters of masticatory and swallowing muscle activity were not significantly different after ECAL. Wide variation was noted in the effect of ECAL on the ipsilateral muscle activity. Blood supply compensation from collaterals of the internal carotid artery may occur in response to the impaired blood flow.

DOI： 10.1152/ajpgi.00226.2023

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Language：English   Publisher：新潟歯学会  

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BACKGROUND: Chewing and licking are primarily activated by central pattern generator (CPG) neuronal circuits in the brainstem and when activated trigger repetitive rhythmic orofacial movements such as chewing, licking and swallowing. These CPGs are reported to modulate orofacial reflex responses in functions such as chewing. OBJECTIVE: This study explored the modulation of reflex responses in the anterior and posterior bellies (ant-Dig and post-Dig, respectively) of the digastric muscle evoked by low-intensity trigeminal stimulation in conscious rats. METHODS: The ant-Dig and post-Dig reflexes were evoked by using low-intensity electrical stimulation applied to either the right or left inferior alveolar nerve. Peak-to-peak amplitudes and onset latencies were measured. RESULTS: No difference was observed between threshold and onset latency for evoking ant-Dig and post-Dig reflexes, suggesting that the latter was also evoked disynaptically. The peak-to-peak amplitude of both reflexes was significantly reduced during chewing, licking and swallowing as compared to resting period and was lowest during the jaw-closing phase of chewing and licking. Onset latency was significantly largest during the jaw-closing phase. Inhibitory level was similar between the ant-Dig and post-Dig reflex responses and between the ipsilateral and contralateral sides. CONCLUSION: These results suggest that both the ant-Dig and post-Dig reflex responses were significantly inhibited, probably due to CPG activation during feeding behaviours to maintain coordination of jaw and hyoid movements and hence ensure smooth feeding mechanics.

DOI： 10.1111/joor.13537

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Anticholinergic medication causes impaired swallowing with hyposalivation. However, the underlying mechanisms by which these drugs modulate the swallowing reflex remain unclear. This study investigated the effects of the muscarinic acetylcholine receptor (mAChR) non-specific antagonist atropine on the initiation of swallowing. Experiments were performed on 124 urethane-anesthetized rats. A swallow was evoked by either topical laryngeal application of a small amount of distilled water (DW), saline, citric acid, or capsaicin; upper airway distention with a continuous airflow; electrical stimulation of the superior laryngeal nerve (SLN); or focal microinjection of NMDAinto the lateral region of the nucleus of the solitary tract (L-nTS). Swallows were identified by electromyographic bursts of the suprahyoid and thyrohyoid muscles. Either atropine, the peripheral mAChR antagonist methylatropine, or antagonists of mAChR subtypes M1-M5 were intravenously delivered. Atropine at a dose of 1 mg/kg increased the number of DW-evoked swallows compared with baseline and did not affect the number of swallows evoked by saline, citric acid, capsaicin, or upper airway distention. Methylatropine and M1-M5 antagonists did not significantly change the number of DW-evoked swallows. Bilateral SLN transection completely abolished DW-evoked swallows, and atropine decreased the swallowing threshold of SLN electrical stimulation. Finally, microinjection of NMDA receptor antagonist AP-5 into the L-nTS inhibited DW-evoked swallows, and atropine facilitated the initiation of swallowing evoked by NMDA microinjection into this region. These results suggest that atropine facilitates DW-evoked swallows via central mAChR actions.

DOI： 10.1152/ajpgi.00039.2023

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The effects of head and neck alignment and pharyngeal anatomy on epiglottic inversion remain unclear. This study investigated the factors involved in epiglottic inversion, including head and neck alignment and pharyngeal anatomy, in patients with dysphagia. Patients with a chief complaint of dysphagia and who underwent videofluoroscopic swallowing study at our hospital from January to July 2022 were enrolled. They were divided into three groups based on the degree of epiglottic inversion as the complete-inversion (CI), partial-inversion (PI), and non-inversion group (NI) groups. Data were compared among the three groups; a total of 113 patients were analyzed. The median age was 72.0 (IQR: 62.0-76.0) years; 41 (36.3%) and 72 (63.7%) were women and men, respectively. There were in 45 (39.8%) patients in the CI, 39 (34.5%) in the PI, and 29 (25.7%) in the NI groups, respectively. Single-variable analysis revealed significant relation to epiglottic inversion of Food Intake LEVEL Scale score, penetration-aspiration score with 3-mL thin liquid bolus, epiglottic vallecula and pyriform sinus residue, hyoid position and displacement during swallowing, pharyngeal inlet angle (PIA), epiglottis to posterior pharyngeal wall distance, and body mass index. Logistic regression analysis with complete epiglottic inversion as the dependent variable revealed the X coordinate at maximum hyoid elevation position during swallowing and PIA as significant explanatory variables. These results suggest that epiglottic inversion is constrained in patients with dysphagia who have poor head and neck alignment or posture and a narrow pharyngeal cavity just before swallowing.

DOI： 10.1007/s00455-023-10579-w

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Authorship：Corresponding author   Language：Japanese   Publisher：(公財)8020推進財団  

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BACKGROUND: It has not yet been clarified how the type of the chewing task affects related muscle activity and how the suprahyoid muscles contribute to masticatory function in humans. OBJECTIVES: This study aimed to investigate the difference in the suprahyoid muscle activity between the freely and unilaterally chewing tasks and between the working and non-working sides during chewing. MATERIALS AND METHODS: Twenty healthy volunteers were instructed to chew peanuts and two different types of rice crackers in two ways; freely and unilaterally while surface electromyograms of the masseter and suprahyoid muscles were recorded. The chewing duration, number of chewing cycles and chewing rate were compared between the tasks. Further, the masseter and suprahyoid muscle activities per chewing cycle were compared between the sides. RESULTS: The chewing duration was significantly longer and the chewing rate was significantly higher during unilaterally chewing than freely chewing. The chewing duration differed significantly among the different foods; the harder the food, the longer the duration. Chewing rate was significantly higher during soft rice cracker chewing as well as suprahyoid activity per chewing cycle. Masseter activity was higher on the chewing side than on the non-chewing side while there was no difference in suprahyoid activity between the sides. CONCLUSION: The current results demonstrate a difference in the masticatory efficacy between the chewing tasks and a functional role of the suprahyoid muscles during chewing, which does not differ between the chewing and non-chewing sides.

DOI： 10.1111/joor.13373

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Dysphagia is sometimes accompanied by pain. Because orofacial structures subserve mastication and swallowing, orofacial pain might impair both functions. Tongue biting can occur not only accidentally while eating but also in some pathological conditions. However, it remains unclear whether noxious mechanical stimulation of the tongue affects swallowing. To explore this question, we evaluated the effects of lingual pinch stimulation on the initiation of swallowing evoked by distilled water (DW) infusion with a flow rate of 5.0 µL/s for 20 s into the pharyngolaryngeal region in anesthetized rats. The swallowing reflex was identified by electromyographic (EMG) bursts in the suprahyoid muscles which include the anterior belly of the digastric muscle, mylohyoid and geniohyoid muscles, and laryngeal elevation by visual inspection. The number of DW-evoked swallows during pinch stimulation was significantly smaller than that in a control condition or during pressure stimulation. The onset latency of the first swallow during pinch stimulation was significantly longer than that in the control condition. DW-evoked swallowing was almost abolished following bilateral transection of the superior laryngeal nerve (SLN) compared with the control condition, suggesting that the SLN plays a crucial role in the initiation of DW-evoked swallowing. Finally, electrophysiological data indicated that some SLN-responsive neurons in the nucleus tractus solitarii (nTS) exhibited delayed latency from a single SLN stimulation during lingual pinch stimulation. These results suggest that noxious mechanical stimulation of the tongue inhibits the initiation of swallowing and modulates neuronal activity in the nTS.

DOI： 10.1007/s00455-022-10522-5

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Language：Japanese   Publisher：(一社)日本言語聴覚士協会  

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Language：Japanese   Publisher：(一社)日本老年歯科医学会  

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BACKGROUND: Outcome prediction for dysphagia recovery is essential for rehabilitation treatment planning. Several studies have reported various predictors for resuming oral feeding after post-stroke dysphagia. However, evidence on oral health and function, a crucial part of feeding, has rarely been reported. Therefore, the goal of this study was to identify the oral status-related factors that could predict oral intake resumption in acute stroke patients. METHODS: 80 acute stroke patients with dysphagia were included. Clinical data, including the changes of general condition, oral and swallowing functions, were collected once a week until discharge. Patients were divided into two groups based on the outcome of the food intake level scale at discharge, and data were compared between the groups. RESULTS: 60 patients had regained complete oral intake before discharge. Multiple logistic regression showed that posterior tongue pressure could significantly predict complete oral intake recovery. Tongue pressure and modified water swallowing test score also significantly influenced diet forms. In addition, Spearman correlation analysis showed that improvement of other oral status-related factors, such as oral moisture and dentition status, also indicated the improvement of diet forms and swallowing function during the hospital stay. CONCLUSION: Tongue pressure measurement could be a useful oral status-related indicator for predicting complete oral intake and adjusting diet forms for acute stroke patients during hospitalization. Acute stroke patients should receive proper oral status evaluation and implementation to enhance functional recovery.

DOI： 10.1016/j.jstrokecerebrovasdis.2022.106401

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Language：Japanese   Publisher：日本顎口腔機能学会  

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DOI： 10.1007/s00455-022-10421-9

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It still remains unclear how the suprahyoid muscles function in bolus formation during mastication. This study aimed to investigate the contributory role of the suprahyoid muscles during mastication. A total of 20 healthy young volunteers were asked to perform tongue pressure generation tasks and unilateral mastication tasks using peanuts and two different types of rice crackers. Surface electromyographic (EMG) activity of the masseter and suprahyoid muscles and mandibular kinematics were recorded. Suprahyoid activity increased with increasing tongue pressure. Masticatory duration until the first deglutition differed significantly among the different foods; the harder the food, the longer the duration. This was also the case in masseter activity per masticatory cycle. Masticatory rate and suprahyoid activity per masticatory cycle were significantly higher during soft rice cracker mastication. Masseter activity was higher on the masticatory side than on the non-masticatory side, however, there was no difference in suprahyoid activity between the sides. Suprahyoid activity and jaw gape showed significant positive correlation in the early stage on both the masticatory and non-masticatory sides. The suprahyoid muscles functioned dominantly for jaw-opening during peanut mastication, and for bolus formation, especially in the late stage during soft rice cracker mastication. Bolus formation was performed dominantly on the masticatory side during rice cracker mastication. These findings clearly demonstrate a functional role of the suprahyoid muscles during mastication of solid foods from assessments using both EMG activity and mandibular kinematic recordings.

DOI： 10.3389/fphys.2022.881891

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Language：Japanese   Publisher：新潟歯学会  

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Language：Japanese   Publisher：新潟歯学会  

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Language：Japanese   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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We investigated how swallowing behaviors are affected by the temperature and carbonation of water in healthy humans. Twenty-nine healthy volunteers were instructed to drink as much natural water, carbonated water, or cider as they wanted, and we recorded the volume of solution swallowed and electromyographic (EMG) activity of the masseter and suprahyoid muscles. Sensory tests regarding the ease of holding the solution in the mouth and ease of swallowing were also performed. The volume of carbonated water swallowed was significantly lower than that of natural water and cider. The ease of holding and swallowing the solution significantly differed between solution types such that natural water was the easiest solution to hold and swallow, followed by cider and then carbonated water in both tests. EMG activity was also affected by the solution type. Masseter EMG activity was significantly lower when swallowing natural water compared with carbonated water. Suprahyoid EMG activity was significantly lower when swallowing natural water compared with carbonated water and cider. The volume of solution swallowed was significantly correlated with the ease of holding and swallowing the solution, but not with masseter or suprahyoid EMG activities. The ease of holding and swallowing the solution significantly affected masseter and suprahyoid EMG activities. The results suggested that when participants experienced difficulty holding and swallowing the solution, masseter and suprahyoid EMG activity increased. Considering our findings that mechanical stimulation with bubbles decreased the volume of solution swallowed and increased EMG activities, carbonated water swallowing may be useful in treating deglutition disorders.

DOI： 10.1007/s00455-020-10147-6

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There is wide variation in chewing behaviours, even among healthy humans. Further, the way in which humans determine swallowing initiation when chewing solid foods remains unclear. The current study sought to investigate how the bolus properties change over time during chewing, and to clarify which factors affect chewing and swallowing behaviours, including swallowing initiation, in healthy humans. Twenty-four healthy volunteers were instructed to chew 8 g of steamed rice and spit it out at 50%, 100% and 150% of their own chewing duration, defined as the time of chewing from onset of the first chewing cycle to onset of the first swallow. Chewing and swallowing behaviours were monitored and determined by visual inspection of video recordings. The physical properties such as hardness, cohesiveness and adhesiveness as well as water content of the bolus were measured. In each subject, maximum bite force, tongue pressure and stimulated salivary flow rate were also measured. Hardness gradually decreased, and the cohesiveness and water content of the bolus did not change up to 50% of chewing duration, followed by a slight but significant increase. The adhesiveness of the bolus rapidly decreased at the beginning of chewing. Chewing duration was significantly related to stimulated salivary flow rate; greater salivary flow rate was associated with shorter chewing duration. Variation of chewing duration and swallowing initiation was not dependent on bolus properties during the chewing of steamed rice, but mainly depended on the surface lubrication of the bolus.

DOI： 10.1111/joor.13151

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The factors affecting the survival of patients with aspiration pneumonia (AP) remain unclear. This study aimed to determine whether factors, including oral status, swallowing function, and oral intake level, were related to survival outcomes in older patients hospitalized for AP. The study enrolled patients with AP who were admitted to our hospital between February 2017 and November 2019. Patients were divided into two groups based on the 90-day mortality after the first swallowing function evaluation: survivors and deceased. The data were compared between the two groups. A total of 29 patients were diagnosed with AP. Of these patients, 13 died within 90 days. The numbers of patients who could not use removable dentures and required sputum suctioning and had cough reflex at rest were significantly higher in the deceased than in the survivors. The salivary pooling and pharyngeal clearance scores evaluated by videoendoscopy, International Dysphagia Diet Standardisation Initiative Functional Diet Scale score determined after swallowing function evaluation, and consciousness level were significantly worse in the deceased than in the survivors. There were significant differences in patients' oral status, swallowing function, oral intake level, and consciousness level between the survivors and deceased.

DOI： 10.1007/s00455-021-10306-3

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Language：Japanese   Publisher：日本顎口腔機能学会  

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Other Link： https://search.jamas.or.jp/default/link?pub_year=2021&ichushi_jid=J02994&link_issn=&doc_id=20220607170011&doc_link_id=%2Fex2gakuk%2F2021%2F002701%2F012%2F0032-0033%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fex2gakuk%2F2021%2F002701%2F012%2F0032-0033%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

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BACKGROUND: To date, there have been few guidelines proposed for adjustment of the food consistency, particularly to match the oral function of older adults, which will guide clinicians and caregivers in appropriately modifying food. OBJECTIVE: We investigated how oral, swallowing, and cognitive conditions of older adults who required daily nursing care in a nursing home were associated with different dietary food consistencies. METHODS: Clinical examinations to record dentition status, swallowing, and cognitive functions were performed, and the feeding status, including the food consistencies and need for assistance at lunchtime, was evaluated in 37 older residents in nursing homes. The swallowing function was assessed by performing a modified water-swallowing test, and food swallowing was tested using pudding and rice crackers. The χ2 test was used to determine the relationships among the parameters. RESULTS: No participants were able to take cooked rice, nor regular and soft side dishes. There was no significant relationship between dentition status and feeding status. Of the participants, 95% ate pudding without any problems and 49% ate rice crackers without any signs of swallowing difficulty such as coughing or stopping chewing. There was a significant relationship between the food test score using a rice cracker and the level of food consistencies, and between the same test score and the level of mealtime assistance, whereby the better the score of the food test using a rice cracker, the better was the level of food consistencies including use of a thickening agent and the better was the level of mealtime assistance. CONCLUSION: The results strongly suggest that the food test using a rice cracker was associated with the level of food consistency and mealtime assistance for older adults in nursing homes.

DOI： 10.1159/000511912

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Examining the coordination of respiration and swallowing is important for elucidating the mechanisms underlying these functions and assessing how respiration is linked to swallowing impairment in dysphagic patients. In this study, we assessed the coordination of respiration and swallowing to clarify how voluntary swallowing is coordinated with respiration and how mastication modulates the coordination of respiration and swallowing in healthy humans. Twenty-one healthy volunteers participated in three experiments. The participants were asked to swallow 3 ml of water with or without a cue, to drink 100 ml of water using a cup without breathing between swallows, and to eat a 4-g portion of corned beef. The major coordination pattern of respiration and swallowing was expiration-swallow-expiration (EE type) while swallowing 3 ml of water either with or without a cue, swallowing 100 ml of water, and chewing. Although cueing did not affect swallowing movements, the expiratory time was lengthened with the cue. During 100-ml water swallowing, the respiratory cycle time and expiratory time immediately before swallowing were significantly shorter compared with during and after swallowing, whereas the inspiratory time did not differ throughout the recording period. During chewing, the respiratory cycle time was decreased in a time-dependent manner, probably because of metabolic demand. The coordination of the two functions is maintained not only in voluntary swallowing but also in involuntary swallowing during chewing. Understanding the mechanisms underlying respiration and swallowing is important for evaluating how coordination affects physiological swallowing in dysphagic patients.

DOI： 10.3389/fphys.2021.696071

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Capsaicin powerfully evokes the swallowing reflex and is a known therapeutic agent for improving dysphagia and preventing aspiration pneumonia. However, the role of capsaicin-sensitive nerves in the initiation of swallowing evoked by various natural stimuli remains unclear. To explore this question, we blocked laryngeal capsaicin-sensitive nerves following the coapplication of QX-314 and capsaicin (QX/Cap), and investigated the effects on swallowing evoked by mechanical and chemical stimulation in anesthetized rats. Swallows were evoked by capsaicin, carbonated water (CW), distilled water (DW), and punctate mechanical stimulation using von Frey filaments applied topically to the larynx. Swallows were documented by recording electromyographic activation of the suprahyoid and thyrohyoid muscles. The initiation of swallowing by capsaicin was strongly suppressed at 5 min following QX/Cap treatment and returned in a time-dependent manner. CW-evoked swallows at 5 min following QX/Cap treatment were significantly diminished compared with before and 30 min after treatment. In contrast, DW-evoked and mechanically evoked swallows were unchanged by QX/Cap treatment. Furthermore, CW-evoked swallows were virtually abolished by transection of the superior laryngeal nerves and significantly decreased by the topical application of acid-sensing ion channel-3 (ASIC3) inhibitor APETx2, but they were not affected by the nonselective transient receptor potential channel inhibitor ruthenium red or the ASIC1 inhibitor mambalgin-1. Taken together, we speculate that capsaicin-sensitive nerves play an important role in the initiation of CW-evoked swallows.NEW & NOTEWORTHY The initiation of swallowing evoked by laryngeal capsaicin and carbonated water application was diminished by the coapplication of QX-314 and capsaicin. Carbonated water-evoked swallows were also abolished by transection of the superior laryngeal nerves and were inhibited by the acid-sensing ion channel-3 inhibitor. Capsaicin-sensitive nerves are involved in the initiation of carbonated water-evoked swallows.

DOI： 10.1152/ajpgi.00233.2020

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We investigated how the physical properties of food affect chewing kinematics, and examined the effects of aging on behavior. Twenty young and 21 older volunteers were asked to freely chew rice crackers and spit the food out at their average chewing duration. We compared chewing characteristics among the conditions (age × rice cracker), and examined the area of rectified masseter and suprahyoid electromyographic bursts per chewing cycle. We also evaluated temporal changes in those values. In addition, the bolus properties at the end of chewing were compared. The harder/larger the rice cracker, the longer the chewing duration and the greater the number of chewing cycles. These values also increased with age. Chewing cycle time was not affected by age and rice cracker properties, except in one condition: for the rice cracker with the lowest hardness and density, the chewing cycle time was longer than for the other rice crackers. Chewing cycle time decreased at the middle stage of chewing, followed by an increase, with increasing suprahyoid electromyographic activity at the late stage. The physical properties of the bolus at the end of chewing did not differ between age groups, and depended on the initial properties. The water absorption rate of the bolus was significantly greater for the rice cracker with the lowest hardness and density compared with other rice crackers. The results demonstrated that not only hardness, but also other factors, such as density, significantly affected chewing behaviors.

DOI： 10.1016/j.physbeh.2020.113102

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A major component of gastric acid is hydrochloric acid (HCl), which can activate transient receptor potential vanilloid 1 (TRPV1). In the present study, we investigated how sustained laryngeal TRPV1 activation affects the frequency of the swallowing reflex. Experiments were carried out on 85 male Sprague-Dawley rats. The effects of short and sustained application of chemicals (3 µl of 0.1 N HCl or capsaicin) on the frequency of swallowing and on time-dependent changes in the occurrence of swallowing evoked by supralaryngeal nerve stimulation were determined. To evaluate vascular permeability of the larynx, Evans blue dye was intravenously injected after 5 or 60 min of sustained TRPV1 activation. SB366791 (a TRPV1 inhibitor) and Cap/QX-314 (a TRPV1-expressed neuronal inhibitor) significantly inhibited HCl/capsaicin-induced swallowing, but air flow-induced swallowing was not affected. Although the number of air flow-induced swallows followed by capsaicin stimulation was not affected within 5 min, it was significantly reduced by 60-min capsaicin or HCl application. The swallowing threshold associated with supralaryngeal nerve stimulation did not significantly change throughout the recording period. Evans blue dye concentrations in the larynx were significantly higher at 60 min in the 10-5 M capsaicin group than in the control group. Our results suggest that sustained TPRV1 activation not only desensitizes TRPV1 but also inactivates mechanoreceptors, which may be attributed to increases in vascular permeability and edema, as part of an inflammatory process.NEW & NOTEWORTHY Although a transient receptor potential vanilloid 1 (TRPV1) inhibitor or TRPV1-expressed neuronal inhibitor significantly inhibited HCl/capsaicin-evoked swallowing, air flow-induced swallowing was not affected. The number of air flow-induced swallows was significantly reduced within 60 min of TRPV1 activation. Evans blue dye concentration in the larynx increased 60 min after capsaicin application. TPRV1 activation not only desensitizes TRPV1 but also inactivates mechanoreceptors caused by increases in vascular permeability and edema.

DOI： 10.1152/ajpgi.00082.2020

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BACKGROUND: There is a wide variation of chewing behaviours even in healthy humans. The present study was aimed to clarify how the rheological properties of the bolus during chewing are different among individuals. We also investigated whether the swallowing threshold was consistent among the individuals and whether the difference in the bolus properties at the swallowing affected swallowing movement. METHODS: Twenty-nine healthy volunteers were asked to ingest 8 g of steamed rice. Based on the chewing duration defined by the time until first swallow, participants were asked to chew the food and then either spit it out or swallow it at 50%, 100% and 150% of chewing duration. In seven volunteers, the maximum bite force was measured. RESULTS: The hardness of the bolus gradually decreased throughout recording. Although the chewing duration varied widely, there was a significant negative correlation between time and hardness, regardless of the difference in individual chewing duration. The cohesiveness of the bolus was unchanged at the 100% time point, followed by a slight but significant increase. There was no significant correlation between the chewing duration and adhesiveness of the bolus. Swallowing-related bursts of Supra and Infra EMGs were not related to the chewing duration or bolus properties, and chewing duration did not affect swallowing function. CONCLUSION: The current results suggest that the bolus properties such as the hardness and cohesiveness during chewing are just dependent on the chewing duration and the difference in the bolus properties does not affect the swallowing initiation and movement.

DOI： 10.1111/joor.13044

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BACKGROUND: Tongue lift movement (TLM) task is considered a treatment strategy in dysphagic patients. However, there is no evidence of effect of sustained tongue movements on the related muscle contraction. OBJECTIVES: The present study aimed to characterise the properties and time-dependent changes of the electromyographic (EMG) features of suprahyoid muscles during TLM. METHODS: Twenty young healthy volunteers were instructed to perform TLM at maximum effort in either the anterior or the posterior position, during measurement of tongue pressure for 7 s. Supra- (S-hyo) and infra-hyoid (I-hyo) EMGs were recorded. The area and power frequency of EMG burst and the area under the curve of tongue pressure were compared among the conditions: trials (1st, 2nd vs 3rd trials); anterior vs posterior TLM; and early vs late 3 s of each trial. RESULTS: There was no difference in the tongue pressure among trials or between the early and late 3 s. Anterior tongue pressure was significantly higher than posterior tongue pressure (P < .001). The area of I-hyo EMG burst was significantly larger (P = .044), and the power frequency of I-hyo EMG burst was significantly smaller (P = .042) during posterior TLM than anterior TLM. A significant difference in the power frequency of both EMG bursts was observed between early and late stages during both anterior (P < .05) and posterior (P < .01) TLM. CONCLUSION: Hyoid muscles may compensate for rapid fatigue of the tongue muscle to maintain tongue pressure by changing their activity pattern during tongue pressure generation.

DOI： 10.1111/joor.12894

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Coughing, huffing and swallowing protect the airway from aspiration. This study was conducted to compare the physical properties of voluntary coughing, huffing and swallowing in healthy subjects. Ten healthy men were asked to huff, cough and swallow repeatedly. Electromyograms (EMGs) were recorded from the left side of the external oblique (EO), sternocleidomastoid, suprahyoid (SH) and thyrohyoid muscles. Airflow was recorded using a face mask with two-way non-rebreathing valves. The expiratory velocity of huffing and coughing and the SH EMG of all actions presented high intraclass correlation coefficients (> 0.8). The inspiratory and expiratory velocities did not differ significantly between coughing and huffing. The expiratory acceleration of coughing was significantly higher than that of huffing, whereas the expiratory volume of coughing was significantly smaller than that of huffing. The EO EMG of coughing and huffing were significantly larger than that of swallowing. The EO EMG activity during the expiratory phase was significantly higher than that of the other phases of both coughing and huffing. The SH EMG of coughing and huffing were significantly smaller than that of swallowing. Correlation analysis revealed that the expiratory velocity of coughing was strongly positively correlated with that of huffing. The expiratory volume of huffing was significantly positively correlated with hand grip strength. These results suggest that EO and SH muscle activities during huffing or coughing differ those during swallowing, and huffing and coughing may work similarly in expiratory function.

DOI： 10.1371/journal.pone.0242810

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Language：English   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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KEY POINTS: Afferents carried by the superior laryngeal nerve play a primary role in the initiation of laryngeal mechanically evoked swallows in anaesthetized rats. Amiloride and its analogues inhibit swallowing evoked by mechanical stimulation, but not swallowing evoked by chemical and electrical stimulation. The epithelial sodium channel is probably involved in the initiation of laryngeal mechanically evoked swallows. ABSTRACT: The swallowing reflex plays a critical role in airway protection. Because impaired laryngeal mechanosensation is associated with food bolus aspiration, it is important to know how the laryngeal sensory system regulates swallowing initiation. This study was performed to clarify the neuronal mechanism of mechanically evoked swallows. Urethane-anaesthetized Sprague-Dawley male rats were used. A swallow was identified by activation of the suprahyoid and thyrohyoid muscles on electromyography. The swallowing threshold was measured by von Frey filament and electrical stimulation of the larynx. The number of swallows induced by upper airway distension and capsaicin application (0.03 nmol, 3 μl) to the vocal folds was counted. The effects of topical application (0.3-30 nmol, 3 μl) of the epithelial sodium channel (ENaC) blocker amiloride and its analogues (benzamil and dimethylamiloride), acid-sensing ion channel (ASIC) inhibitors (mambalgine-1 and diminazene) and gadolinium to the laryngeal mucosa on swallowing initiation were evaluated. A nerve transection study indicated that afferents carried by the superior laryngeal nerve play a primary role in the initiation of laryngeal mechanically evoked swallows. The mechanical threshold of swallowing was increased in a dose-dependent manner by amiloride and its analogues and gadolinium, but not by ASIC inhibitors. The number of swallows by upper airway distension was significantly decreased by benzamil application. However, the initiation of swallows evoked by capsaicin and electrical stimulation was not affected by benzamil application. We speculate that the ENaC is involved in the initiation of laryngeal mechanically evoked swallows.

DOI： 10.1113/JP277895

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KEY POINTS: Despite evidence that the human cerebellum has an important role in swallowing neurophysiology, the effects of cerebellar stimulation on swallowing in the disrupted brain have not been explored. In this study, for the first time, the application of cerebellar neurostimulation is characterized in a human model of disrupted swallowing (using a cortical virtual lesion). It is demonstrated that cerebellar stimulation can reverse the suppressed activity in the cortical swallowing system and restore swallowing function in a challenging behavioural task, suggesting the findings may have important therapeutic implications. ABSTRACT: Repetitive transcranial magnetic stimulation (rTMS) can alter neuronal activity within the brain with therapeutic potential. Low frequency stimulation to the 'dominant' cortical swallowing projection induces a 'virtual-lesion' transiently suppressing cortical excitability and disrupting swallowing behaviour. Here, we compared the ability of ipsi-lesional, contra-lesional and sham cerebellar rTMS to reverse the effects of a 'virtual-lesion' in health. Two groups of healthy participants (n = 15/group) were intubated with pharyngeal catheters. Baseline pharyngeal motor evoked potentials (PMEPs) and swallowing performance (reaction task) were measured. Participants received 10 min of 1 Hz rTMS to the pharyngeal motor cortex which elicited the largest PMEPs to suppress cortical activity and disrupt swallowing behaviour. Over six visits, participants were randomized to receive 250 pulses of 10 Hz cerebellar rTMS to the ipsi-lesional side, contra-lesional side or sham while assessing PMEP amplitude or swallowing performance for an hour afterwards. Compared to sham, active cerebellar rTMS, whether administered ipsi-lesionally (P = 0.011) or contra-lesionally (P = 0.005), reversed the inhibitory effects of the cortical 'virtual-lesion' on PMEPs and swallowing accuracy (ipsi-lesional, P < 0.001, contra-lesional, P < 0.001). Cerebellar rTMS was able to reverse the disruptive effects of a 'virtual lesion'. These findings provide evidence for developing cerebellar rTMS into a treatment for post-stroke dysphagia.

DOI： 10.1113/JP277545

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We examined how attention alters chewing and swallowing behaviors. Twenty-one healthy volunteers were asked to freely eat 8 g of steamed rice in three separate trials, and we obtained the average number of chewing cycles (N) and chewing duration (T) prior to the first swallow in each trial. We also conducted an N-limited test, in which participants chewed the food while independently counting the number of chewing cycles and swallowed the food when they reached N, and a T-limited test, in which they chewed the food for T sec and then swallowed. We recorded electromyograms (EMGs) from masseter and suprahyoid muscles and collected videoendoscopic images. In the N-limited test, chewing speed decreased, masseter muscle activity (area under the curve of the rectified EMG burst) per cycle increased, and suprahyoid muscle activity per cycle decreased. In the T-limited test, the chewing speed increased, muscle activities per cycle decreased, and the number of cycles increased. The occurrence frequency of bolus propulsion into the pharynx before swallowing was smaller in the N- and T-limited tests than in the free chewing test. Further, the whiteout time was longer in the T-limited test than in the free chewing test. Attentional chewing changes not only chewing but also swallowing behavior.

DOI： 10.1038/s41598-019-42422-4

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This study aimed to investigate whether the jaw-opening (JOR) and jaw-closing reflexes (JCR) are modulated during not only peripherally, but also centrally, evoked swallowing. Experiments were carried out on 24 adult male Japanese white rabbits. JORs were evoked by trigeminal stimulation at 1 Hz for 30 s. In the middle 10 s, either the superior laryngeal nerve (SLN) or cortical swallowing area (Cx) was simultaneously stimulated to evoke swallowing. The peak-to-peak JOR amplitude was reduced during the middle and late 10-s periods (i.e., during and after SLN or Cx stimulation), and the reduction was dependent on the current intensity of SLN/Cx stimulation: greater SLN/Cx stimulus current resulted in greater JOR inhibition. The reduction rate was significantly greater during Cx stimulation than during SLN stimulation. The amplitude returned to baseline 2 min after 10-s SLN/Cx stimulation. The effect of co-stimulation of SLN and Cx was significantly greater than that of SLN stimulation alone. There were no significant differences in any parameters of the JCR between conditions. These results clearly showed that JOR responses were significantly suppressed, not only during peripherally evoked swallowing but also during centrally evoked swallowing, and that the inhibitory effect is likely to be larger during centrally compared with peripherally evoked swallowing. The functional implications of these results are discussed.

DOI： 10.1016/j.brainres.2018.05.002

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Language：Japanese   Publisher：新潟歯学会  

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Swallowing pressure generation is important to ensure safe transport of an ingested bolus without aspiration or leaving residue in the pharynx. To clarify the mechanism, we measured swallowing pressure at the oropharynx (OP), upper esophageal sphincter (UES), and cervical esophagus (CE) using a specially designed manometric catheter in anesthetized rats. A swallow, evoked by punctate mechanical stimulation to the larynx, was identified by recording activation of the suprahyoid and thyrohyoid muscles using electromyography (EMG). Areas under the curve of the swallowing pressure at the OP, UES, and CE from two trials indicated high intrasubject reproducibility. Effects of transecting the hypoglossal nerve (12N) and recurrent laryngeal nerve (RLN) on swallowing were investigated. Following bilateral hypoglossal nerve transection (Bi-12Nx), OP pressure was significantly decreased, and time intervals between peaks of thyrohyoid EMG bursts and OP pressure were significantly shorter. Decreased OP pressure and shortened times between peaks of thyrohyoid EMG bursts and OP pressure following Bi-12Nx were significantly increased and longer, respectively, after covering the hard and soft palates with acrylic material. UES pressure was significantly decreased after bilateral RLN transection compared with that before transection. These results suggest that the 12N and RLN play crucial roles in OP and UES pressure during swallowing, respectively. We speculate that covering the palates with a palatal augmentation prosthesis may reverse the reduced swallowing pressure in patients with 12N or tongue damage by the changes of the sensory information and of the contact between the tongue and a palates. NEW & NOTEWORTHY Hypoglossal nerve transection reduced swallowing pressure at the oropharynx. Covering the hard and soft palates with acrylic material may reverse the reduced swallowing function caused by hypoglossal nerve damage. Recurrent laryngeal nerve transection reduced upper esophageal sphincter negative pressure during swallowing.

DOI： 10.1152/japplphysiol.00944.2017

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Surface electrical stimulation of the laryngeal region is used to improve swallowing in dysphagic patients. However, little is known about how electrical stimulation affects tongue movements and related functions. We investigated the effect of electrical stimulation on tongue pressure and hyoid movement, as well as suprahyoid and infrahyoid muscle activity, in 18 healthy young participants. Electrical stimulation (0.2-ms duration, 80 Hz, 80% of each participant's maximal tolerance) of the laryngeal region was applied. Each subject swallowed 5 ml of barium sulfate liquid 36 times at 10-s intervals. During the middle 2 min, electrical stimulation was delivered. Tongue pressure, electromyographic activity of the suprahyoid and infrahyoid muscles, and videofluorographic images were simultaneously recorded. Tongue pressure during stimulation was significantly lower than before or after stimulation and was significantly greater after stimulation than at baseline. Suprahyoid activity after stimulation was larger than at baseline, while infrahyoid muscle activity did not change. During stimulation, the position of the hyoid at rest was descended, the highest hyoid position was significantly inferior, and the vertical movement was greater than before or after stimulation. After stimulation, the positions of the hyoid at rest and at the maximum elevation were more superior than before stimulation. The deviation of the highest positions of the hyoid before and after stimulation corresponded to the differences in tongue pressures at those times. These results suggest that surface electrical stimulation applied to the laryngeal region during swallowing may facilitate subsequent hyoid movement and tongue pressure generation after stimulation. NEW & NOTEWORTHY Surface electrical stimulation applied to the laryngeal region during swallowing may facilitate subsequent hyoid movement and tongue pressure generation after stimulation. Tongue muscles may contribute to overshot recovery more than hyoid muscles.

DOI： 10.1152/japplphysiol.00512.2017

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Pharyngeal electrical stimulation (PEStim) has been found to facilitate voluntary swallowing. This study investigated how PEStim contributed to modulation of swallowing function in 15 healthy humans. In the involuntary swallowing test, water was injected onto the pharynx at 0.05 ml/s and the onset latency of the first swallow was measured. In the voluntary swallowing test, subjects swallowed their own saliva as quickly as possible for 30 s and the number of swallows was counted. Voluntary and involuntary swallowing was evaluated before (baseline), immediately after, and every 10 min after 10-min PEStim for 60 min. A voluntary swallowing test with simultaneous 30-s PEStim was also conducted before and 60 min after 10-min PEStim. The number of voluntary swallows with simultaneous PEStim significantly increased over 60 min after 10-min PEStim compared with the baseline. The onset latency of the first swallow in the involuntary swallowing test was not affected by 10-min PEStim. The results suggest that PEStim may have a long-term facilitatory effect on the initiation of voluntary swallowing in healthy humans, but not on peripherally-evoked swallowing. The physiological implications of this modulation are discussed.

DOI： 10.1371/journal.pone.0190608

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Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Stomatognathic Function  

DOI： 10.7144/sgf.24.130

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Publisher：Japanese Society of Stomatognathic Function  

DOI： 10.7144/sgf.25.32

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Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Stomatognathic Function  

DOI： 10.7144/sgf.24.128

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/joor.12555

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PubMed

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1152/ajpgi.00299.2016

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PubMed

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Language：Japanese   Publisher：日本口腔リハビリテーション学会  

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Language：Japanese   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.brainresbull.2016.02.015

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PubMed

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.physbeh.2015.12.024

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PubMed

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/joa.12426

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PubMed

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.physbeh.2015.10.004

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PubMed

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Language：Japanese   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.physbeh.2015.08.003

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PubMed

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier  

DOI： 10.1016/j.foodhyd.2014.09.029

Scopus

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.brainresbull.2014.12.008

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PubMed

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Language：Japanese   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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Language：Japanese   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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Language：Japanese   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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Language：Japanese   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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Language：Japanese   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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Language：Japanese   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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Language：English   Publishing type：Research paper (scientific journal)  

The tongue is important for orofacial movements, including swallowing. Although numerous studies have focused on tongue pressure against the palate, its physiological role has not been fully evaluated. The tongue pressure generation may have the temporal coordination with the swallowing relational organs. The aim of this study was to clarify the physiological mechanisms of tongue pressure and to investigate the temporal relationship among tongue pressure, supra-hyoid muscle activity, and videofluorographic (VF) images during swallowing. Fifteen healthy young subjects participated. Tongue pressure measured using a sensor sheet with five channels, electromyographic EMG, and VF was recorded synchronously during 4-ml barium swallowing. Swallowing behavior in VF images with and without the sensor sheet was compared. Furthermore, the temporal relationship between events measured from tongue pressure, EMG, and VF was evaluated. Swallowing behavior on VF images was not affected by placement of the sensor sheet. Tongue pressure at the posterio-lateral point of the hard palate tended to have biphasic peaks. Tongue pressure production with a monophasic pattern appeared during the same period as the second peak in the biphasic pattern. The onset of tongue pressure was later than the start of hyoid movement and onset of EMG, and offset was observed between the hyoid at the up-forward position and reposition. Onset of tongue pressure at the anterior area was correlated with the start of slight hyoid elevation. Offset of tongue pressure at the posterio-lateral points was strongly time locked with the hyoid at the up-forward position. The present results suggested the temporal coordination of tongue pressure generation with the swallowing-related organs. That is, the tongue pressure was produced for bolus propulsion, and was closely related to hyoid movement temporally during swallowing. These results may contribute to clarify the clinical state with the disorder of tongue kinetics.

DOI： 10.1002/phy2.167

PubMed

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.neulet.2012.12.047

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PubMed

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/j.1469-7580.2012.01501.x

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/j.1469-7580.2011.01404.x

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Language：Japanese   Publisher：Japan Prosthodontic Society  

<B>Purpose:</B> This study aimed to define the relationship between satisfaction of wearing denture and three factors ("easy to chew", "retention in chewing", "absence of pain"), as well as the missing teeth pattern with Miyachi classification, the chewing ability.<br><B>Methods:</B> A total of 256 subjects (born in 1927) living in Niigata city, Japan who had answered a questionnaire survey in 2007 on the relationship between oral health and health status were selected for this study. Satisfaction with dentures and three factors ("easy to chew", "retention in chewing", and "absence of pain") were evaluated with the VAS score. This study also investigated grouping the pattern of missing teeth based on the Miyachi classification. In addition, a questionnaire was conducted to investigate whether the elderly people could chew around 15 different food items or not.<br><B>Result:</B> It was clearly shown that satisfaction with dentures was correlated with the three points of chewing easily, stability, and pain-free among elderly people. However, none of the three points showed a far stronger correlation than the others. The results also showed that there was no relation between the missing teeth pattern classified with the Miyachi classification and satisfaction with dentures. The results of the questionnaire revealed that the number of food items taken by the elderly people was significantly lower in the group not satisfied with dentures than the other groups (Excellent, good, poorly satisfaction group). <br><B>Conclusion:</B> It was confirmed that chewing easily, stability and pain-free enhance satisfaction with dentures. However, satisfaction with dentures was not ascribed to the pattern of missing teeth; accordingly, we consider that we can keep elderly people satisfied by fabricating good dentures and performing appropriate adjustments regardless of difficult patterns of missing teeth.

DOI： 10.2186/ajps.1.361

CiNii Article

CiNii Books

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Other Link： http://search.jamas.or.jp/link/ui/2010031506

Language：Japanese   Publisher：新潟歯学会  

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Language：Japanese   Publisher：新潟歯学会  

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Language：Japanese   Publisher：新潟歯学会  

J-GLOBAL

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Language：Japanese   Publisher：(公財)8020推進財団  

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Language：Japanese   Publisher：(一社)日本摂食嚥下リハビリテーション学会  

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2016&ichushi_jid=J03152&link_issn=&doc_id=20170524040003&doc_link_id=%2Fcb5dvsph%2F2016%2F002002%2F003%2F0080-0085%26dl%3D0&url=http%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fcb5dvsph%2F2016%2F002002%2F003%2F0080-0085%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

J-GLOBAL

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J-GLOBAL

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Authorship：Corresponding author   Language：Japanese   Publisher：新潟歯学会  

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Event date： 2018.6

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Event date： 2018.6

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聴神経腫瘍術後に嚥下障害を認めた一例を報告する。症例は56歳女性。2017年2月に小脳・脳幹を圧迫する聴神経鞘腫に対する摘出術施行、術後左小脳出血及び延髄から橋にかけて低吸収域を認めたため、脳内血腫除去および減圧開頭術が施行された。術後11日目に嚥下機能評価目的に当科初診となった。小脳前庭症状としての姿勢保持困難と失調性構音障害、球麻痺症状としての顔面神経麻痺、舌運動減弱、開鼻声を伴う右カーテン徴候を認めた。反復唾液嚥下テストは2回、改訂水飲みテストおよびとろみ付液体3ccでのテストでは3a点(嚥下後湿性音あり)であった。嚥下内視鏡検査時、安静時より咽頭内分泌物貯留、左側披裂・声帯は傍正中位固定で声門閉鎖不良、ホワイトアウトは減弱しており、とろみ付液体摂取時の食道流入不良、鼻咽腔逆流を認めた。さらに、残留物は不顕性誤嚥をしていた。重度摂食嚥下障害の診断にて、口腔ケア・間接訓練から介入を開始した。耐久性が改善した術後19日目以降は間接訓練の負荷を増やし、少量のとろみ付液体を用いた直接訓練も開始した。術後35日目に実施した嚥下造影検査では、依然として嚥下後の咽頭残留量が多く食事開始にはいたらなかった。転院を前に術後55日目に実施した最終評価では、幻暈などの前庭症状は改善していたものの球麻痺症状に大きな変化は認められなかった。最終的に食事開始までは至らなかったものの、訓練の効果による咽頭残留の軽減と姿勢調整を行うことで安全な経口摂取方法の提案ができた。(著者抄録)

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Event date： 2018.6

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Event date： 2018.6

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Event date： 2018.6

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頭頸部癌術後は、高頻度に摂食嚥下障害を生じる。今回、舌癌術後に摂食嚥下障害を生じ、リハビリテーションによる食形態や姿勢の調整によって経口摂取が可能となった症例を経験したので報告する。症例は68歳の男性。舌亜全摘術、両側頸部郭清術、腹直筋皮弁再建術、気管切開術、胃瘻造設術後、放射線治療開始と同時にN大学医歯学総合病院摂食嚥下機能回復部に紹介受診となった。初診時、頸部拘縮、舌切除による創部瘢痕化を伴う口腔移送不良・鼻咽腔閉鎖不全・咽頭収縮不全を認めた。嚥下内視鏡検査と嚥下造影検査により、リクライニング60度、左側臥位・右側頸部回旋位にてとろみ付液体2ccの食道流入が可能なことを確認して、毎日の間接訓練および代償法を用いた直接訓練を開始した。術後放射線治療の影響による口腔粘膜炎は自制内であり、訓練手技を獲得して耐久性が向上した介入29日目より食事開始、介入35日目には口腔移送改善を目的として舌接触補助床を用いた訓練を開始したものの、違和感や嘔気が強く常時使用にはいたらなかった。今後は、経口摂取のみでの栄養確保、歯科補綴学的アプローチによる口腔準備期の改善も可能であると考えている。(著者抄録)

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Event date： 2018.3

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2018&ichushi_jid=J02994&link_issn=&doc_id=20190314220013&doc_link_id=%2Fex2gakuk%2F2018%2F002402%2F013%2F0128-0129%26dl%3D0&url=http%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fex2gakuk%2F2018%2F002402%2F013%2F0128-0129%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Event date： 2018.3

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2018&ichushi_jid=J02994&link_issn=&doc_id=20190314220014&doc_link_id=%2Fex2gakuk%2F2018%2F002402%2F014%2F0130-0131%26dl%3D0&url=http%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fex2gakuk%2F2018%2F002402%2F014%2F0130-0131%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Event date： 2018.2

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退院時に独歩をめざす「DOPPOプロジェクト」への参加意思があるN病院入院患者32名を対象とし、リハビリ開始時に口腔・嚥下機能の評価と身体機能評価を行い、相互の関連性について検討した。口腔機能の評価項目は[咬合力][グミ咀嚼能力][舌圧][口唇閉鎖力]、嚥下機能の評価項目は[3オンス水飲みテスト][反射唾液嚥下テスト(RSST)]とした。身体機能の評価項目は[握力][下肢伸展力][SPPB][10m歩行時の速度および歩数][6分間歩行距離]とした。検討の結果、口腔機能と身体機能との関連性については、多くの項目間で有意な相関が認められた。嚥下機能が低下している群(15名)と非低下群に分けて身体機能各項目の群間比較を行ったところ、低下群は[SPPB]が有意に低く、[10m歩行時の歩数]が有意に多かった。歩行速度が<0.8m/sの16名を"歩行速度低下群"、他の16名を"非低下群"として口腔・嚥下機能各項目の群間比較を行ったところ、低下群は[咬合力][グミ咀嚼能力][舌圧][RSST]が有意に低値であった。

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Event date： 2018

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2017&ichushi_jid=J02994&link_issn=&doc_id=20180411290011&doc_link_id=%2Fex2gakuk%2F2017%2F002401%2F011%2F0040-0041%26dl%3D0&url=http%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fex2gakuk%2F2017%2F002401%2F011%2F0040-0041%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Event date： 2017.9

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Event date： 2017.9

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Event date： 2017.9

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Event date： 2017.9

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2017&ichushi_jid=J04306&link_issn=&doc_id=20171005130271&doc_link_id=10.11477%2Fmf.6001200137&url=https%3A%2F%2Fdoi.org%2F10.11477%2Fmf.6001200137&type=%88%E3%8F%91.jp_%83I%81%5B%83%8B%83A%83N%83Z%83X&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00024_2.gif

Event date： 2017.9

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2017&ichushi_jid=J02994&link_issn=&doc_id=20170814470006&doc_link_id=%2Fex2gakuk%2F2017%2F002302%2F006%2F0122-0123%26dl%3D0&url=http%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fex2gakuk%2F2017%2F002302%2F006%2F0122-0123%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Event date： 2017.3

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2017&ichushi_jid=J02994&link_issn=&doc_id=20170814470009&doc_link_id=%2Fex2gakuk%2F2017%2F002302%2F009%2F0128-0129%26dl%3D0&url=http%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fex2gakuk%2F2017%2F002302%2F009%2F0128-0129%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

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Event date： 2016.9

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Event date： 2016.8

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介護保険施設において、口腔ケアおよび摂食指導を必要としている要介護高齢者は少なくない。今後、研修歯科医が食事の場面に立ち会い、摂食指導をすることが重要であるが、その機会はまだ少ないと考えられる。新潟大学では、特別養護老人ホームを週に1回訪問し、口腔ケアや摂食指導を行っているが、その際に研修歯科医が2〜3名ずつ同行して、実際の口腔ケアや摂食指導を研修している。今後、よりよい研修プログラムを提供するため、研修歯科医の介護保険施設における口腔ケアおよび摂食指導の経験の有無や、本プログラムを研修した感想等に関するアンケート調査を実施した。対象は、2009〜2013年度に、口腔ケアおよび摂食指導の研修を行った本学研修歯科医144名とし、口腔ケアおよび摂食指導に対する知識・経験の有無について調査した。その結果、80.4%が口腔ケアの知識があると回答していたが、実際に口腔ケアあるいは摂食指導を経験したことがある者は少なかった(口腔ケア56.6%、摂食指導18.2%)。また、大半が、口腔ケアおよび摂食指導が勉強になったと回答していた。口腔ケアあるいは摂食指導に対する歯科専門スタッフの介入価値があると思うと回答した者は、口腔ケアでは82.5%、摂食指導では78.3%と高い割合を示した。要介護高齢者の数は増加の一途をたどっており、今後、口腔ケアおよび摂食指導において歯科医師が果たす役割は、ますます大きくなっていくと思われる。患者家族やコメディカルに摂食指導をする立場にある歯科医師の臨床研修に、介護保険施設等における口腔ケアおよび摂食指導を導入することは重要であるといえる。(著者抄録)

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Event date： 2016.7

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Event date： 2016.6

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Event date： 2016.3

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2016&ichushi_jid=J02994&link_issn=&doc_id=20160908470016&doc_link_id=%2Fex2gakuk%2F2016%2F002202%2F016%2F0146-0147%26dl%3D0&url=http%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fex2gakuk%2F2016%2F002202%2F016%2F0146-0147%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Event date： 2015.9

Language：Japanese  

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Event date： 2015.9

Language：Japanese  

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Event date： 2015.9

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Event date： 2015.3

Language：Japanese  

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2015&ichushi_jid=J02994&link_issn=&doc_id=20150812230014&doc_link_id=%2Fex2gakuk%2F2015%2F002102%2F014%2F0142-0143%26dl%3D0&url=http%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fex2gakuk%2F2015%2F002102%2F014%2F0142-0143%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Event date： 2014.12

Language：Japanese  

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Event date： 2014.12

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Event date： 2014.12

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Event date： 2014.9

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Event date： 2014.9

Language：English  

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Event date： 2014.9

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Event date： 2014.9

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Event date： 2014.9

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Other Link： https://search.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2014&ichushi_jid=J02994&link_issn=&doc_id=20150213300013&doc_link_id=%2Fex2gakuk%2F2014%2F002101%2F013%2F0052-0053%26dl%3D0&url=http%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fex2gakuk%2F2014%2F002101%2F013%2F0052-0053%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Event date： 2014.9

Language：Japanese  

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Event date： 2014.6

Language：Japanese  

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Event date： 2014.6

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Event date： 2014.4

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超高齢社会の到来に伴い、訪問歯科診療の需要も増加しているが、供給は十分になされていないのが現状である。その理由として、在宅の訪問歯科診療実施が不安だという報告もある。今後、増加する訪問歯科診療の需要に応えるには、歯学部学生に対して、訪問歯科診療見学実習を実施し、実習後に評価を行って実習内容の改善に努めることが必要であると考える。新潟大学歯学部歯学科では、1998年から6年次生に対して訪問歯科診療見学実習を行っている。今回、訪問歯科診療に対する意識および現在行われている訪問歯科診療見学実習の評価に関する情報収集を目的として、質問紙法による調査を実施した。2013年に、6年次生を対象とした訪問歯科診療見学実習前後に無記名の質問紙調査を行い、比較検討した。解析対象となった33名全員が、実習を有意義であると回答していた。有意差は認められなかったものの、訪問歯科診療を「大変」と思う者および訪問歯科診療に対する不安は実習後に減少しており、訪問歯科診療を実際に見学することによって訪問歯科診療の実状を知ることができたためだと考えられる。その一方、見学後の総括で、訪問歯科診療で行うことが可能な診療や診療姿勢についての指導が必要であることも明らかになった。今後、見学内容をさらに改善し、継続していきたいと考えている。(著者抄録)

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Event date： 2014.3

Language：Japanese  

摂食に関連した咽頭と食道機能の加齢変化とその関係について検討した。健常若年男性10例、健常高齢男性12例を対象とした。全ての被験食で若年者と比較して高齢者で食道内残留スコアが高値を示した。とろみ液体、粥で若年者と比較して高齢者で咽頭内残留スコアが高値を示した。嚥下反射惹起ポイントは全ての被験食で若年者と比較して高齢者で高値を示した。若年者群では食道、咽頭、口腔の各パラメータ間で有意な相関を認めなかったが、高齢者群では食道内残留と咽頭、口腔のいくつのパラメータ間で相関を認めた。とろみ液体と粥では咽頭内残留スコアが高い被験者は食道内残留スコアも有意に高値を示した。とろみ液体と粥では、嚥下反射惹起ポイントが高い被験者は食道内残留スコアが有意に高値を示した。とろみ液体と粥では、Eichner's分類B群およびC群がA群と比較して食道内残留スコアが有意に高かった。

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Event date： 2014.2

Language：Japanese  

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Event date： 2014.1

Language：Japanese  

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Event date： 2013.12

Language：Japanese  

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Event date： 2013.12

Language：Japanese  

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Event date： 2013.9

Language：Japanese  

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Event date： 2013.9

Language：Japanese  

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Event date： 2013.2

Language：Japanese  

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Event date： 2013.2

Language：Japanese  

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Event date： 2011.9

Language：Japanese  

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