Purpose：Even though the degree of recovery after dental treatment varies more greatly among patients wearing removable dentures than those without, there have been few studies on the relationship between masticatory function and cognitive function. The aim of this study was to reveal the oral function of elderly people wearing removable dentures with a risk of cognitive decline in comparison with elderly people wearing no dentures and those wearing dentures with normal cognitive function.

　Methods：Two hundred a ninety nine elderly people were divided into four groups as follows：subjects wearing no dentures with normal cognitive function, subjects wearing no dentures with cognitive decline, subjects wearing dentures with normal cognitive function, and subjects wearing dentures with cognitive decline. The number of teeth, masticatory function, maximum biting force, and intake of 25 foods were measured by questionnaire and oral diadochokinesis.

　Results：Comparing the four groups, the number of teeth and masticatory function declined significantly in subjects wearing dentures with cognitive decline. Furthermore, the subjects were divided into three categories by area of missing teeth and their oral function was analyzed. Masticatory function and intake of 25 foods declined in subjects wearing complete dentures with cognitive decline.

　Conclusion：Elderly people wearing complete dentures with cognitive decline have lower masticatory function according to both subjective and objective evaluations.

　Background：Although malnutrition hinders the recovery of inpatients, the potential contribution of dentists to the Nutrition Support Team（NST）has not been fully elucidated.

　Objectives：To clarify the nutritional risk status of hospitalized patients with suspected dysphagia and related factors.

　Method：The preparatory and oral stages（occlusal support area with remaining teeth/dentures, use of dentures, maximum tongue pressure, masticatory ability）and pharyngeal stage（repetitive saliva swallowing test, modified water swallowing test, Hyodoʼs score by videoendoscopic examination）of swallowing, nutritional risk（Geriatric Nutritional Risk Index＝GNRI）, consciousness level（Japan Coma Scale）and diet modification level were evaluated in patients who were admitted to the Department of Oral and Maxillofacial Surgery, Aidu Chuo Hospital Dental and Oral Medical Center for suspected dysphagia from April 2015 to April 2019. The subjects were divided into two groups according to the nutritional status：medium/severe nutritional risk（GNRI＜92）and no/mild nutritional risk（GNRI≥92）, and each item was compared between the groups by the Chi square test and Mann-Whitneyʼs U test. Factors for medium/severe nutritional risk were investigated by binomial logistic analysis.

　Results：Subjects in the medium/severe nutritional risk group（n＝285）were older and showed lower denture use ratio, functional occlusal support, masticatory performance and each score of swallowing function than those in the no/mild nutritional risk group（n＝30）. GNRI was significantly higher in the normal diet group than in the other diet modification groups. As a result of binomial logistic analysis, age, parenteral intake, and Hyodoʼs score were selected as items associated with malnutrition.

　Conclusion：Factors associated with nutritional risk of inpatients suspected of dysphagia in general hospitals were identified, which included factors associated with oral function.

　Purpose：The present study aimed to investigate the prevalence of oral hypofunction（OHF）and its association with nutritional status in patients undergoing gastrectomy.

　Methods：A total of 214 patients who underwent gastrectomy were prospectively recruited from June 2018 to March 2020. Seven sub-symptoms of OHF were measured and patients were diagnosed as OHF if they met more than three criteria of seven symptoms. Nutritional status was measured using the Mini Nutrition Assessment（MNA）. Age was categorized into young（＜70 years）and old（≥70 years）groups. The differences in the OHF measures and the prevalence of OHF were statistically tested by age category and cancer clinical stage（CS）. The association between OHF and MNA was also tested.

　Results：The mean values of tongue pressure, lip-tongue motor function, and occlusal force were significantly lower in the older group. Tongue pressure was also affected by the severity of CS. The prevalence of OHF was 25％ in the young group but increased to 39％ in the older group. In patients with CS of 2 or more, the prevalence of decreased tongue pressure, lip-tongue motor function, or occlusal force was significantly higher in the older group. MNA score was significantly lower in the OHF group than in the non-OHF group.

　Conclusion：We found that oral function had declined in old gastric cancer patients before surgery regardless of cancer clinical stage. We also found that OHF was associated with malnutrition, suggesting that assessment and intervention for OHF could be considered as part of perioperative nutritional management.

　Objectives：Conventional scaling with an ultrasonic scaler is associated with a risk of aspiration of contaminated water because of water irrigation；therefore, it is difficult to perform the procedure in bedridden old patients. Sumi et al. developed an oral care system without using water. We consider that scaling with an ultrasonic scaler can be safely performed without water irrigation by applying the system and using an oral care gel developed by Sumi et al. In this study, we performed scaling with an ultrasonic scaler using the oral care gel without water irrigation, with the aim of evaluating the amount of water running down the throat and its harmful effect on the periodontal tissues.

　Methods：Scaling with an ultrasonic scaler was performed without water irrigation using the oral care gel. Patient satisfaction and discomfort were compared between the procedures with and without water irrigation. In addition, the procedure was performed in bedridden patients, and pharynx invasion, its harmful effect on the periodontal tissues, and presence or absence of fever were evaluated.

　Results：Pharynx invasion during scaling with the ultrasonic scaler using the oral care gel was very small, and there was no evidence of fever suggestive of aspiration after the procedure in any of the patients. Patient satisfaction or the procedure-associated pain or discomfort did not differ between the groups with and without water irrigation. Additionally, there were no harmful pulp responses or abnormal findings of the gingiva.

　Conclusions：Scaling using the oral care gel was hardly associated with a risk of aspiration of contaminated water, etc. even in bedridden patients, or with its harmful effects on the pulp and gingiva. These results suggest that scaling with an ultrasonic scaler can be safely performed using the oral care gel even in bedridden old patients.