記述言語：英語   掲載種別：研究論文（学術雑誌）  

BACKGROUND: The tongue functions by modulating according to bolus volume when swallowing; however, associated tongue dynamics are unclear. OBJECTIVE: We aimed to clarify how tongue motion and tongue pressure change with bolus volume during swallowing. METHODS: Sixteen healthy volunteers (age 29.5 ± 3.8 years; 12 males, 4 females) were recruited. Two electromagnetic articulography markers were attached, one each on the anterior and posterior parts of the tongue, to measure motion. A sensor sheet, with five pressure-sensitive points, was attached to the hard palate to measure tongue pressure. Participants were asked to swallow 3 ml and 10 ml of water. Motion trajectory, maximum velocity, vertical displacement just before contact with the hard palate, and maximum magnitude and duration of tongue pressure were analysed. RESULTS: Tongue rotation was observed in the sagittal plane; its rate of appearance was significantly higher when swallowing 3 ml of water than when swallowing 10 ml, and the rate of rotation at posterior part was significantly higher than at the anterior part. The maximum velocity and vertical displacement were significantly greater when swallowing 10 ml of water than those when swallowing 3 ml of water. There was no significant difference in either the maximum magnitude of tongue pressure or maximum duration of tongue pressure between 3 ml and 10 ml. CONCLUSION: Bolus volume influenced the pattern of tongue motion; however, there was no difference in tongue pressure.

DOI： 10.1111/joor.13248

PubMed

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掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1111/joor.13208

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

To provide appropriate foods for elderly people with eating difficulties, it is necessary to take account of the ability of compensatory mastication such as tongue squeezing. However, the biomechanics of tongue squeezing is still unclear. The aim of present study is to investigate the effect of the initial mechanical properties of gels on the change in tongue pressure production during squeezing and swallowing. As test sample, nine kinds of gels with three fracture force and three fracture strain were prepared. Tongue pressure during squeezing and swallowing gels was measured by using an ultra-thin tongue pressure sensor with five measuring points attached on the hard palate in seven healthy participants, and analyzed at four phases; Initial squeeze, Middle squeeze, Last squeeze, and Swallowing. The maximal magnitude of tongue pressure was increased for gels with higher fracture force at most measuring points and was decreased for gels with higher fracture strain at some measuring points on the median line during Initial and Middle squeezing. However, no influence by fracture force and strain was found in magnitude during Last squeezing and Swallowing. The duration of tongue pressure increased for gels with higher force at most measuring points during Middle squeezing, although no influence by strain was found during each phase. The results clearly show how the initial fracture properties of gels influence on tongue pressure production during each phase of food oral processing, which clarified one aspect of squeezing with tongue, as the compensatory mastication.

DOI： 10.1111/jtxs.12593

PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

PURPOSE: In recent years, the chewing frequency, i.e., the number of chewing cycles, has decreased owing to changes in dietary habits. Although these changes may be related to complete body health, there is no evidence-based tool to measure the dietary habits. We developed a small ear-hung wearable device for monitoring mastication behavior. The device, worn on the ear pinna, allows the counting of the number of chewing cycles, and data are collected on a smartphone via Bluetooth. In this study, the reliability of the novel device was verified. METHODS: A total of 22 healthy volunteers participated in the study. During measurement, the subjects wore the novel wearable device on their right ear pinna and were asked to chew gum, gummy jellies, and rice balls. The number of chewing cycles was counted by the device. A mandibular kinesiograph (MKG) was also recorded, and the chewing activity was recorded as a video. The accuracy, precision, and recall of the ear-hung device were calculated by comparing the data obtained from the MKG and the video recording. Additionally, the factors affecting reliability were examined. RESULTS: The accuracy, precision, and recall of the novel device were 101.6 ± 13.6%, 85.3 ± 11.0%, and 84.5 ± 9.5%, respectively. Although the accuracy was not affected by any factor, precision and recall of the novel device for women were significantly worse than that for men, and were greatest when the subjects were chewing gum. CONCLUSIONS: Our findings suggest that the newly developed ear-hung wearable device for counting the number of chewing cycles was sufficiently reliable.

DOI： 10.2186/jpr.JPR_D_20_00032

PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Mastication is a physiological process whereby food is comminuted and mixed with saliva to form a swallowable bolus; it is also the initial process for retronasal aroma that is released from foods to receptors in the nose. However, the influence of mastication state on retronasal aroma is poorly understood. The purpose of this study was to investigate the relationship between aroma concentration and factors related to mastication state. The study design was an analytical observational study. Twelve male volunteers (age, 26.5 ± 2.7 years) were recruited and divided into five and seven participants in the low and high masticatory performance groups, respectively. The stimulated salivary flow rate was measured while participants chewed paraffin wax. First, an odor sensor was placed in the nostril, and the aroma concentration was measured over time as participants chewed an orange-flavored gummy jelly standardized for masticatory performance assessment until swallowing; chewing strokes were counted to determine swallowing thresholds. Next, participants were instructed to chew the gummy jelly for a certain number of strokes (i.e., 50 or 100% of swallowing thresholds, as well as 30 strokes) and expectorate the jelly without swallowing. The surface area of comminuted jelly at 30 chewing strokes was defined as masticatory performance. Maximum and slope of aroma concentration, surface area, number of chewing strokes, and stimulated salivary flow rate were compared between low and high masticatory performance groups. Statistical significance was set at α = 0.05. At 30 chewing strokes, the maximum aroma concentration and the slope were significantly greater in the high masticatory performance group than in the low masticatory performance group. There was a positive correlation between the maximum aroma concentration and the number of chewing strokes with aroma release in both groups. No significant correlation was found between the maximum aroma concentration and the stimulated salivary flow rate. However, multiple regression analysis (with aroma concentration as a dependent variable) showed that the increase in surface area, the number of chewing strokes, and the stimulated salivary flow rate were significant explanatory variables. The results suggested that retronasal aroma was influenced by mastication state and salivary flow rate during chewing.

DOI： 10.3389/fnut.2021.623507

PubMed

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記述言語：日本語

CiNii Books

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記述言語：日本語

CiNii Books

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記述言語：日本語   出版者・発行元：一般社団法人 日本老年歯科医学会  

背景：最大舌圧と栄養状態との関係はまだ十分明らかにされていない。そこで，本研究では総合病院入院中の高齢患者の舌圧と栄養状態ならびに食形態との関連性について検討した。

方法：2015年4月から2020年10月までに，総合病院歯科口腔外科に院内紹介された65歳以上の患者165名（男性96名，女性69名，平均年齢83.5±8.2歳）を対象とした。栄養リスク状態についてはGeriatric Nutritional Risk Indexを用いて中等度・高度群となし・軽度群の2群に分類し，食形態は常食・刻み食群とソフト食・ペースト食群の2群に分けて，それぞれ2群間で最大舌圧の差を検討した。

結果：栄養リスク中等度・高度群（148名）の最大舌圧（14.1±9.6 kPa）は，栄養リスクなし・軽度群（19.8±10.8 kPa）と比べて有意に低かった（p＝0.043）。一方，ソフト食・ペースト食群（88名）の最大舌圧（12.4±9.6 kPa）は，常食・刻み食群（16.9±9.6 kPa）と比べて有意に低かった（p＝0.001）。また，ROC曲線により得られた栄養リスク中等度・高度ならびにソフト食・ペースト食を予測するカットオフ値は，それぞれ18.6 kPaと16.5 kPaであった。

結論：総合病院入院高齢患者における最大舌圧の低下は，低栄養や食形態レベルの低下と関係していた。

DOI： 10.11259/jsg.36.91

CiNii Article

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J-GLOBAL

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J-GLOBAL

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J-GLOBAL

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開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

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開催年月日： 2021年8月 - 2021年9月

記述言語：英語   会議種別：ポスター発表  

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開催年月日： 2021年7月

記述言語：英語   会議種別：ポスター発表  

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受賞区分：国際学会・会議・シンポジウム等の賞 

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