Updated on 2026/03/15

写真a

 
SASA Anna
 
Organization
Academic Assembly Institute of Medicine and Dentistry SHIGAKU KEIRETU Assistant Professor
Graduate School of Medical and Dental Sciences Oral Life Science Oral Biological Science Assistant Professor
Title
Assistant Professor
External link

The Best Research Achievement in Research Career

Degree

  • 学士（言語聴覚療法） ( 2015.3   北海道医療大学 )

Research Interests

  • motion capture

  • 言語聴覚障害

  • mastication

  • dysphagia

Research Areas

  • Life Science / Rehabilitation science  / Dysphagia

Research History (researchmap)

  • Niigata University Graduate School of Medical and Dental Sciences   Division of Dysphagia Rehabilitation   Assistant Professor

    2024.4

    　 More details

  • 新潟大学大学院医歯学総合研究科   摂食嚥下リハビリテーション学分野   非常勤研究員

    2022.4 - 2024.3

    　 More details

  • Niigata University Graduate School of Medical and Dental Sciences   Division of Dysphagia Rehabilitation   Project Research Assistant

    2017.1 - 2022.3

    　 More details

  • Public Interest Association of Medical Service for Workers Kin-ikyo Chuo Hospital   Speech Therapist

    2015.4 - 2016.12

    　 More details

Research History

  • Niigata University   Institute of Medicine and Dentistry, Academic Assembly   Assistant Professor

    2024.4

  • Niigata University   Oral Biological Science, Oral Life Science, Graduate School of Medical and Dental Sciences   Assistant Professor

    2024.4

  • Niigata University   Graduate School of Medical and Dental Sciences   Specially Appointed Assistant

    2020.5 - 2022.3

  • Niigata University   Institute of Medicine and Dentistry, Academic Assembly   Specially Appointed Assistant

    2020.5 - 2022.3

  • Niigata University   Graduate School of Medical and Dental Sciences   Specially Appointed Assistant

    2019.4 - 2020.3

  • Niigata University   Graduate School of Medical and Dental Sciences   Specially Appointed Assistant

    2017.1 - 2019.3

▶ display all

Education

  • Health Sciences University of Hokkaido   School of Psychological Science   Department of Communication Disorders

    2010.4 - 2015.3

    　 More details

    Country： Japan

    researchmap

  • Niigata University   Graduate School of Medical and Dental Sciences   Oral Life Science

    2018.4

    　 More details

    Country： Japan

    Notes： Devision of Dysphagia Rehabilitation

    researchmap

 

Papers

  • Effect of Hyposalivation on Fish Cake Mastication in Healthy Individuals. International journal

    Chisato Aizawa, Reiko Ita, Yuto Ochiai, Anna Sasa, Namon Phetnin, Yoko Kawana, Kazuhiro Ono, Natsuka Takada, Takanori Tsujimura, Jin Magara, Makoto Inoue

    Food science & nutrition   14 ( 1 )   e71378   2026.1

    　More details

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

    During mastication, solid food is mixed with saliva to form a bolus. However, little is known about the effects of hyposalivation on mastication. The effects of hyposalivation on masticatory behavior were investigated using fish paste products. Healthy volunteers (n = 21) were instructed to eat two fish paste products (fish cakes and rolled omelets) in a natural manner. These foods are elastic with high water content. Electromyographic activity was recorded in the masseter, suprahyoid, and infrahyoid muscles during mastication before and after atropine administration, which reduced salivary flow. Masticatory dynamics, including electromyographic activity and masticatory cycle time, were compared between volunteers with and without hyposalivation, and among the early, middle, and late masticatory stages. Next, the volunteers (n = 19) were instructed to ingest the food in the same manner and then spit it out at the end of mastication. After atropine administration, spitting was repeated, and bolus properties, such as hardness, water content, and piece size, were compared between the conditions. Hyposalivation did not affect any fish cake sensory evaluation properties; however, masticatory duration for rolled omelet increased considerably. Furthermore, no significant differences were observed between volunteers with and without hyposalivation in terms of masticatory cycle time, muscle activity per cycle at each stage, bolus physical properties, and bolus water content. Owing to the high water content of fish paste products, such as fish cake or rolled omelet, hyposalivation may not substantially affect mastication of these products.

    DOI： 10.1002/fsn3.71378

    PubMed

    researchmap

  • Effect of Hyposalivation on Masticatory Movements While Eating Several Crackers in Healthy Individuals. International journal

    Kazuki Ikeura, Yuto Ochiai, Anna Sasa, Kazuhiro Ono, Ryo Takei, Hideaki Washio, Hajime Takahashi, Jin Magara, Takanori Tsujimura, Makoto Inoue

    Journal of oral rehabilitation   52 ( 12 )   2401 - 2411   2025.12

    　More details

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

    BACKGROUND: Salivation is important during mastication for bolus formation. OBJECTIVES: This study aimed to examine the effect of reduced salivary flow on the mastication of crackers. METHODS: Twenty-one healthy adults were instructed to masticate three foods: rice crackers with (rice cracker 1) and without (rice cracker 2) fat and seasoning and wheat cracker with fat. Atropine sulphate (1 mg) was used to reduce salivary flow. RESULTS: Hyposalivation significantly extended the masticatory duration (p = 0.020) and masticatory cycle time (p = 0.002) for all test foods. The masticatory cycle time in the late stage significantly increased with hyposalivation of rice cracker 2 (p = 0.002) and wheat cracker (p < 0.001). Suprahyoid muscle activity per masticatory cycle significantly increased with hyposalivation for rice cracker 2 on both the masticatory (p = 0.017) and non-masticatory sides (p = 0.026). There were no differences in these values between the rice cracker 1 conditions. Stimulated salivary flow was the highest in rice cracker 1 (p = 0.002) among the foods. CONCLUSION: Taste stimulation can compensate for impaired mastication through the inhibition of salivary flow. Although the fat content can assist in the manipulation of the bolus, the manufacturing process or location of the fat content in the cracker should be considered.

    DOI： 10.1111/joor.70048

    PubMed

    researchmap

  • Lingual pressure as a physiological indicator for dysphagia in amyotrophic lateral sclerosis and multiple system atrophy. International journal

    Jin Magara, Taku Suzuki, Midori Yoshihara, Wakana Onuki, Anna Sasa, Takanori Tsujimura, Makoto Inoue

    Neurodegenerative disease management   1 - 10   2025.11

    　More details

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

    BACKGROUND: This study aimed to characterize lingual pressure (LP) and clarify its association with dysphagia in patients with amyotrophic lateral sclerosis (ALS) and multiple system atrophy (MSA). METHODS: We examined 52 patients with ALS (Spinal-onset, 39; bulbar-onset, 13) and 36 patients with MSA (MSA-C, 26; MSA-P, 10). LP was measured using a balloon-type instrument during isometric contractions. Maximum LP (MLP) and 80% endurance of LP (ELP; duration above 80% of MLP during 7 seconds) were analyzed against videofluoroscopic findings of dysphagia. RESULTS: Both parameters significantly correlated with food intake scales, especially in ALS. Liquid aspiration was predicted in ALS with 80.8% accuracy (AUC = 0.794, p < 0.001) using MLP cutoff of 20.5 kPa, and in MSA with 75.0% accuracy (AUC = 0.786, p < 0.01) using an ELP cutoff of 1.68 second. Predictive accuracy improved in spinal-onset ALS and MSA-C. CONCLUSION: LP thus may represent a physiological indicator for dysphagia detection and management.

    DOI： 10.1080/17582024.2025.2580876

    PubMed

    researchmap

  • The Instruction of Chewing Well Affects Masticatory Activity and Bolus Flow During Rice Chewing in Healthy Humans. International journal

    Akira Okubo, Takanori Tsujimura, Rumi Ueha, Taku Suzuki, Eri Takei, Anna Sasa, Yuhei Tsutsui, Yuta Nakajima, Jin Magara, Makoto Inoue

    Journal of oral rehabilitation   52 ( 10 )   1736 - 1745   2025.10

    　More details

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

    BACKGROUND: Chewing well (CW) is widely recommended for general health. OBJECTIVE: The study aimed to consider what healthy participants associated with the instruction of 'CW' and to investigate the effects of CW on masticatory activity and bolus flow during rice chewing. METHODS: Twenty-six healthy participants ate 8, 12 and 16 g of steamed rice with barium sulphate under the following two instructions: chewing freely and CW. We investigated the masticatory muscle activity by electromyography (EMG) and the bolus flow by videofluoroscopy. A paired t-test or Wilcoxon signed-rank test was used to analyse data. RESULTS: All participants associated the 'CW' instruction with 'chewing for a long time'. CW shortened the masseter (Mas) EMG burst duration per chewing cycle (p < 0.001). At 8 and 12 g, CW decreased the suprahyoid (Shy) EMG activity per chewing cycle (p < 0.05) and increased the ratio of valleculae and hypopharyngeal time (VHT) to chewing time (p < 0.01). CW increased the chewing rate in the VHT for 8 and 12 g (p < 0.05) and in the processing time for 16 g (p < 0.05) in the participants who reached the food bolus in the valleculae area during chewing. CONCLUSION: CW decreased the Mas activity during chewing at all volumes, while its effects on the Shy activity and bolus flow during chewing depended on the mouthful volume. CW increased the chewing rate in the final stage for the small and medium volumes, and in the early stage for the large volume.

    DOI： 10.1111/joor.14034

    PubMed

    researchmap

  • Effect of carbonation and thickening on voluntary swallow in healthy humans. International journal

    Hajime Iwamori, Jin Magara, Wakana Onuki, Reiko Ita, Anna Sasa, Takanori Tsujimura, Makoto Inoue

    Journal of oral rehabilitation   2024.7

    　More details

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

    BACKGROUND: Liquid modification is a widely established strategy of treatment for patients with dysphagia. The modification of liquid particularly by thickening or carbonation is a common approach to promote safe swallowing. OBJECTIVE: This study sought to investigate how carbonated and/or thickened water modulates swallowing behaviours during swallowing in healthy young individuals. METHODS: Thirty-one healthy volunteers (9 men, 22 women; mean age ± standard deviation [SD], 25.7 ± 6.2 years) were instructed to swallow 20 mL of water, carbonated water and carbonated juice with and without added thickening agent. Electromyograms (EMGs) of the suprahyoid (S-hyo) muscles were recorded to evaluate swallowing behaviours. Obtained S-hyo EMG bursts was analysed using the following outcome parameters: onset latency, the time between swallowing que to onset of EMG burst; rising time and falling time, defined as the time between onset and peak, and between peak and offset, respectively; duration, defined as the time between onset and offset of EMG burst; and area integral value under the waveform. RESULTS: Effects of thickening demonstrated the extended onset latency, EMG burst duration including falling time and the larger area of EMG in thickened liquid compared to thin liquid, but there was not much difference between thin and thickened carbonated liquids. Carbonation significantly decreased the duration including falling time for thickened but not for thin liquids. CONCLUSION: Patients with dysphagia can benefit from use of carbonated or thickened water while the effects on swallowing physiology may differ between carbonation and thickening.

    DOI： 10.1111/joor.13793

    PubMed

    researchmap

  • Effect of bolus property on swallowing dynamics in patients with dysphagia. International journal

    Haruka Hino, Taku Suzuki, Kazuya Maekawa, Reiko Ita, Anna Sasa, Sirima Kulvanich, Eri Takei, Jin Magara, Takanori Tsujimura, Makoto Inoue

    Journal of oral rehabilitation   2024.4

    　More details

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

    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

    PubMed

    researchmap

  • Chewing Well Modulates Pharyngeal Bolus Transit During Swallowing in Healthy Participants. International journal

    Akira Okubo, Takanori Tsujimura, Rumi Ueha, Taku Suzuki, Yuhei Tsutsui, Yuta Nakajima, Nobuaki Saka, Anna Sasa, Eri Takei, Jin Magara, Makoto Inoue

    Dysphagia   2024.3

    　More details

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

    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

    PubMed

    researchmap

  • Functional evaluation of jaw and suprahyoid muscle activities during chewing

    Anna Sasa, Sirima Kulvanich, Naohito Hao, Reiko Ita, Masahiro Watanabe, Taku Suzuki, Jin Magara, Takanori Tsujimura, Makoto Inoue

    Journal of Oral Rehabilitation   2022.9

    　More details

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

    DOI： 10.1111/joor.13373

    researchmap

  • Impact of oral function on regaining oral intake and adjusting diet forms for acute stroke patients. International journal

    Sirima Kulvanich, Haruka Sakai, Riho Takanami, Mako Yamada, Anna Sasa, Kayoko Ito, Takanori Tsujimura, Jin Magara, Makoto Inoue

    Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association   31 ( 5 )   106401 - 106401   2022.5

    　More details

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

    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

    PubMed

    researchmap

  • Functional Role of Suprahyoid Muscles in Bolus Formation During Mastication. International journal

    Anna Sasa, Sirima Kulvanich, Naohito Hao, Reiko Ita, Masahiro Watanabe, Taku Suzuki, Jin Magara, Takanori Tsujimura, Makoto Inoue

    Frontiers in physiology   13   881891 - 881891   2022

    　More details

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

    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

    PubMed

    researchmap

  • Coordination of Respiration, Swallowing, and Chewing in Healthy Young Adults. International journal

    Naohito Hao, Anna Sasa, Sirima Kulvanich, Yuta Nakajima, Kouta Nagoya, Jin Magara, Takanori Tsujimura, Makoto Inoue

    Frontiers in physiology   12   696071 - 696071   2021

    　More details

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

    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

    PubMed

    researchmap

  • 舌癌術後の摂食嚥下障害に対し間接訓練ならびに直接訓練を実施した1症例

    小貫 和佳奈, 笹 杏奈, 辻 光順, 渡邊 賢礼, 白石 成, 伊藤 加代子, 真柄 仁, 辻村 恭憲, 井上 誠

    新潟歯学会雑誌   48 ( 1 )   43 - 48   2018.6

    　More details

    Language：Japanese   Publisher：新潟歯学会  

    researchmap

  • 聴神経腫瘍術後に脳幹・小脳出血を合併し摂食嚥下障害を認めた1症例 Reviewed

    笹 杏奈, 辻 光順, 渡邊 賢礼, 那小屋 公太, 伊藤 加代子, 真柄 仁, 辻村 恭憲, 井上 誠

    新潟歯学会雑誌   48 ( 1 )   37 - 41   2018.6

    　More details

    Language：Japanese   Publisher：新潟歯学会  

    researchmap

▶ display all

MISC

▶ display all

 

Teaching Experience

  • 学問の扉 知と方法の最前線

    2025
    Institution name：新潟大学

  • 早期臨床実習IB

    2025
    Institution name：新潟大学

  • 早期臨床実習I

    2025
    Institution name：新潟大学