The Department of Dysphagia Rehabilitation has been established in 2020. In the context of Japan's super-aged society, our goal is to cultivate professionals capable of practicing dysphagia patients. Our clinical targets are not limited to the older patients but also include adults and children, offering treatment modalities for outpatients, home and facility care visits, as well as support for inpatients at TMDU hospitals. Recently, we have also initiated telemedicine. Our research encompasses not only the swallowing functions and its training methods but also investigates the aging changes in the perioral muscles (tongue, masticatory muscles, and swallowing-related muscles), the connection between these changes and overall health, the impacts of oral intake on the body.

1.Development of Devices for Assessing Dysphagia, Oral Function Decline, and Oral Frailty
We are developing an advanced device for quantitatively assessing swallowing functions and their clinical applications. Previously, we developed a mouth-opening force gauge aimed at simplifying the assessment of swallowing function and oral function decline, for which we have obtained a patent. Currently, we are developing devices to measure aspects that were previously difficult to assess, such as jaw movement during chewing, biting force, and the strength of muscles involved in eating and swallowing. Additionally, these devices can be applied not only for dysphagia but also for evaluating oral frailty and oral function decline, which have gained importance in recent years.

2.Nutritional Studies Using a Gastrotomy Model in Rats
In older adults and patients with dysphagia, enteral nutrition methods like gastrostomy are chosen to prevent aspiration pneumonia and malnutrition. While gastrostomy is a nutrition intake method with many advantages, it can also lead to chronic gastrointestinal disorders. Therefore, we have created a gastrotomy model in rats, raising them on various types of nutrition to explore changes in nutritional value and gut microbiota.

3.Image Analysis of Swallowing Function in Patients with Cervical Spine Diseases
There have been several studies on postoperative dysphagia in patients with cervical spine diseases. However, few such patients have kinematically analyzed the causes of dysphagia. In collaboration with the Department of Orthopedic Surgery at our medical school, we analyze the hyoid bone movement before and after surgery in patients with cervical spine diseases based on videofluoroscopic swallow studies to investigate the causes of postoperative dysphagia.

4.Comprehensive Research on the Collaboration between Medical and Dental Care for Stroke Patients
For stroke patients, the effects of interventions and methods for managing oral functions through medical-dental collaboration have not been established. Thus, we introduced early oral function management interventions for stroke patients admitted to our university hospital to reduce the incidence of acute pneumonia. We have also completed a care manual and a medical-dental collaboration guidebook for acute phase stroke patients and are currently verifying the intervention effects in multi-institutional cooperative research, aiming to establish methods for managing oral functions through medical-dental collaboration across Japan.

5.Development of an Innovative Intraoral Device for Alternative Voice Production in Total Laryngectomy Patients
Total laryngectomy patients significantly impair their quality of life due to the loss of speaking function. Although alternative voice methods such as electronic larynxes and esophageal speech have been used, they come with issues like the need for surgery and high costs. We are advancing the development and effectiveness verification of a completely different, removable intraoral alternative voice method.

6.Unraveling Frailty in the Older Adults Focused on Perioral Muscles and Establishing a New Functional Evaluation Method
Frailty and sarcopenia in older adults are widely recognized globally. Although evaluations of frailty focus on muscle mass, strength, and physical function, similar considerations for the perioral muscles have not progressed. We aim to clarify frailty occurring in the perioral muscles using ultrasound diagnostic devices for muscle mass evaluation and dedicated measuring devices for muscle strength and function, establishing a simple, clinically applicable method for assessing oral and swallowing functions.

7. Verification of the Effectiveness of Carbonated Thickened Beverages and Development of a Two-Stage Angle Endoscope for Patients with Dysphagia
Patients with dysphagia often cannot consume carbonated drinks due to the risk of aspiration. While carbonation has been reported to have beneficial effects on swallowing, no studies have been reported on the intake of carbonated drinks thickened to reduce this risk. We are verifying the effects of carbonation on swallowing dynamics with thickened carbonated beverages. Additionally, the design of endoscopes used for evaluating swallowing function has not changed for nearly 30 years. We have developed a two-stage bending endoscope, improving the traditional single-bend shaft, and are verifying its effectiveness. This allows observation of the posterior tracheal wall, potentially improving the detection accuracy of aspiration.

8. Development of a Non-Invasive Swallowing Function Evaluation Device Using Fluorescent Substances
Swallowing endoscopy and videofluoroscopic swallow studies are performed in various clinical settings, but both are invasive and require a high level of operator skill, affecting the accuracy of the examination and diagnosis. Therefore, a practical, non-invasive, and repeatable new examination method is sought. We are developing a non-invasive aspiration risk detection system that applies fluorescence measurement of food-grade fluorescent substances in collaboration with other universities.

9. Research on the Digitalization of Dysphagia Rehabilitation, Including Online Consultations and Intraoral Scanners

Digitalization is steadily progressing in dentistry. The utility of digital technology, including for dysphagia rehabilitation and dental home visit services is increasing, yet its widespread use is currently limited. We are engaged in verifying the usefulness of online consultations and digital devices (especially intraoral scanners) in dysphagia rehabilitation and home visit services, as well as developing new devices suitable for clinical use.

In anticipation of an increasingly aging society, we are dedicated to developing professionals who can contribute to healthcare, nursing care, and society at large through dysphagia rehabilitation and other means. Our undergraduate education not only covers lectures related to dysphagia but also provides opportunities to learn about multidisciplinary collaboration in the field through accompanying home visits, facility visits, or hospital consultations.

We are conducting evaluations of swallowing functions using videoendoscopic and videofluoroscopic evaluation of swallowing, as well as implementing rehabilitation based on these assessments. Our department places a strong emphasis on home healthcare through home visits, striving not only to evaluate the feasibility of oral intake but also to ensure patients can enjoy their lives to the fullest, without losing the joy of eating, by adjusting the consistency of food, posture, and the patient's environment. In outpatient care, we primarily focus on the rehabilitation of patients after oral cancer surgery but also cater to patients with swallowing disorders caused by a variety of diseases, unique to a university hospital setting. Additionally, we have established an environment capable of telemedicine, targeting patients with dysphagia living in medically underserved areas. Telemedicine have also proven to be effective in situations where face-to-face interactions are impossible due to measures against COVID-19.

Our department specializes in providing dysphagia rehabilitation in home healthcare settings. Therefore, we are fully capable of effective collaboration with primary care dentists responsible for oral hygiene and oral function management in dental home visit services. Additionally, telemedicine can be offered not only to patients within the country but also to those abroad.