Wataru Fujii

Bio: Wataru Fujii is an academic researcher from Fujita Health University. The author has contributed to research in topics: Swallowing & Mastication. The author has an hindex of 6, co-authored 9 publications receiving 224 citations.

Chewing and food consistency: effects on bolus transport and swallow initiation.

Abstract: Preswallow bolus formation usually occurs in the mouth for liquids and in the oropharynx for solid foods. We examined the effect of chewing on the relationship between bolus transport and swallow initiation. Fifteen healthy subjects were imaged with lateral projection videofluorography while eating liquids, solid foods, and a mixture of liquid and solid foods in upright and facedown postures. Videotapes were reviewed to measure the location of the leading edge of the barium at swallow initiation. Chewing and initial consistency each altered the relationship between food transport and swallow initiation. In particular, when chewing liquid (or consuming foods with both liquid and solid phases), a portion of the food commonly reached the hypopharynx well before swallow onset. This transport to the hypopharynx was highly dependent on gravity, but transport to the valleculae for chewed solid food was active, depending primarily on tongue-palate contact. Chewing appeared to reduce the effectiveness of the posterior tongue-palate seal, allowing oral contents to spill into the pharynx. Consuming two-phase foods with both solid and liquid phases may increase the risk of aspiration in dysphagic individuals with impaired airway protective reflexes.

Efficacy of a novel training food based on the process model of feeding for mastication and swallowing ― A preliminary study in elderly individuals living at a residential facility ―

Abstract: Nakagawa K, Matsuo K, Shibata S, Inamoto Y, Ito Y, Abe K, Ishibashi N, Fujii W, Saitoh E. Efficacy of a novel training food based on the process model of feeding for mastication and swallowing ― a preliminary study in elderly individuals living at a residential facility ―. Jpn J Compr Rehabil Sci 2014; 5: 72-78. Purpose: We examined the validity and safety of a newly developed chew-swallow managing food (CSM) as a training material for chewing and swallowing. Methods: Twenty-three elderly individuals (mean age: 82.8 ± 8.6 years) who followed a regular diet at a residential facility were enrolled in this study. The subjects ate 4 g each of CSM and puree 3 times while bolus transport and swallowing were recorded with a fiberoptic endoscope. For each trial, the number of chewing and swallowing movements was counted. We also identified the location of the leading edge of the food at swallow initiation, the amount of food residue in the oral cavity and pharynx, and the incidence of aspiration. The differences in measurements between CSM and puree trials were then compared statistically. Results: With the CSM, the number of chewing and swallowing movements was significantly higher than that with puree and the leading edge of the food was deeper in the pharynx at swallow initiation. There were no significant differences in food residue or aspiration between the 2 foods. Conclusion: Our findings suggest that CSM has an initial consistency that requires chewing but changes to a texture equivalent to puree at the time of swallowing. We are currently planning to verify the safety and efficacy of CSM in individuals with dysphagia.

Influence of Chewing on Food Transport and Swallowing

Abstract: 咀嚼嚥下の評価法の確立のため,健常成人10名を対象として,4食物条件下で咀嚼が嚥下反射開始前の食塊位置および嚥下時間経過に及ぼす影響を嚥下造影検査を用いて検討した.液体命令嚥下に比し全咀嚼条件で食塊先端位置の中～下咽頭への到達率が高く,食塊進入には咀嚼の存在が一義的に関与し,食物形態はそれを修飾する役割を担うと思われた.混合咀嚼条件では食塊は全例で嚥下前に中～下咽頭へ到達しており,信頼性の高い負荷法といえた.液体を含む咀嚼嚥下では,下咽頭到達が高率で下咽頭通過時間も長く,誤嚥防止の観点から興味深い所見であった.咀嚼嚥下は命令嚥下とは別様式であり「食べる」機能の評価と位置づけられた.

Hyoid Movement and Laryngeal Penetration During Sequential Swallowing

Abstract: This study examined hyoid movement during sequential swallowing and evaluated the relationship among trajectory patterns, swallowing types based on laryngeal movement and laryngeal penetration. Twelve healthy adults underwent videofluorography during sequential swallowing. Each swallow was classified into two types: opened laryngeal vestibule after swallow (i-Segmental type) and closed laryngeal vestibule after swallow (i-Continuous type). Each participant's swallowing type was classified by the same method. We analyzed two-dimensional movements of the hyoid, and the trajectories were classified into three patterns: hyoid moved in the anterosuperior direction after the onset of swallow (pattern L); hyoid moved in the anterosuperior direction after the onset of swallow, beyond the mandibular plane (pattern X); and the hyoid was above the mandibular plane at the onset of swallow, and then it moved in the inferior direction (pattern U). Two-way ANOVA revealed that there was a significant interaction between the swallowing type and trajectory pattern, and laryngeal penetration was the highest for the combination of individual swallow of i-Continuous type and pattern L. In sequential swallowing, the existence of a penetration-prone swallowing pattern combination was an interesting phenomenon relevant to eating management for dysphagic patients; however further study in patient groups is required.

The Influence of Food Texture and Liquid Consistency Modification on Swallowing Physiology and Function: A Systematic Review

Abstract: Texture modification has become one of the most common forms of intervention for dysphagia, and is widely considered important for promoting safe and efficient swallowing. However, to date, there is no single convention with respect to the terminology used to describe levels of liquid thickening or food texture modification for clinical use. As a first step toward building a common taxonomy, a systematic review was undertaken to identify empirical evidence describing the impact of liquid consistency and food texture on swallowing behavior. A multi-engine search yielded 10,147 non-duplicate articles, which were screened for relevance. A team of ten international researchers collaborated to conduct full-text reviews for 488 of these articles, which met the study inclusion criteria. Of these, 36 articles were found to contain specific information comparing oral processing or swallowing behaviors for at least two liquid consistencies or food textures. Qualitative synthesis revealed two key trends with respect to the impact of thickening liquids on swallowing: thicker liquids reduce the risk of penetration–aspiration, but also increase the risk of post-swallow residue in the pharynx. The literature was insufficient to support the delineation of specific viscosity boundaries or other quantifiable material properties related to these clinical outcomes. With respect to food texture, the literature pointed to properties of hardness, cohesiveness, and slipperiness as being relevant both for physiological behaviors and bolus flow patterns. The literature suggests a need to classify food and fluid behavior in the context of the physiological processes involved in oral transport and flow initiation.

Relationships between oral health, dysphagia and undernutrition in hospitalised elderly patients.

Abstract: Objective The aim of this study was to describe relationships between oral status, dysphagia and malnutrition in a hospitalised older people. Background Undernutrition in older people is a major concern in geriatric hospital wards. Different factors can modify nutritional status like dysphagia or oral status. Materials and methods About 159 consecutive inpatients (108 women, 51 men) were examined. Comprehensive gerontological data at baseline and nutritional status according to BMI, MNA and serum albumin concentration, dependency according to ADL scores, dietary intake, swallowing capacities and oral status were collected. Swallowing capacities and dietary intake were reassessed 1 week after. Results Mean age was 85.28 (SD 5.68). Seventy-seven patients were malnourished (MNA) and 34 had dysphagia. Oral treatment was necessary in 142 patients (89.30% of all population). Candidiasis was present in 17 patients and salivary flow reduction in 50. Patients with dysphagia had the lowest dietary intake. After 1 week, patients with dysphagia were retested and dysphagia had abated in three of them. Dysphagia and undernutrition were associated (p < 0.001), and both were related to candidiasis (p < 0.001 and p < 0.01). Dysphagia was also related to salivary hypofunction (p < 0.001), loss of posterior occluding pairs (POPs; p = 0.014), oral self-care dependency (p < 0.001) and self-feeding dependency (p < 0.001). Salivary hypofunction was related to candidiasis (p < 0.001) and loss of POPs (p < 0.05), and candidiasis to loss of POPs (p < 0.01). Conclusion Although no causality can be demonstrated, poor oral health was strongly associated with malnutrition, emphasising the importance to develop oral care strategies and to incorporate a dental examination into comprehensive gerontological assessment.