In this study, we conducted a free questionnaire survey of students with the aim of evaluating the usefulness and points requiring improvement of practical training based on studentsʼ impressions, and studied the results using a text mining method. We conducted a questionnaire survey of 5th grade dental students who underwent practical training of oral health care and swallowing treatment for geriatrics. We analyzed the results using a text mining method, and drew a co-occurrence network by subgraph detection and betweenness centrality.

　As a result, in the network diagram of subgraph detection, the impressions of the students as a whole were grouped into seven topics, and various contents were shown. In particular, “slightly”, “times”, “increasing” and “clinical” co-occurred. The contents of those impressions were mainly a demand for practical training such as an increase in the number of times of clinical practice and an increase in photographs of cases. In the network diagram of betweenness centrality, the words “actual”, “practical training”, “elderly”, “dentistry”, “experience”, “person” and “bad” had high betweenness centrality in all students, and each word co-occurred. These words appeared to co-occur mainly for contents which displayed an understanding of the elderly through their own experiences. Based on these results, it was suggested that students described diverse impressions and they mainly described contents which displayed an understanding of the elderly through their own experiences. Therefore, these results suggest that the practical training is useful by promoting understanding of the elderly and that an educational and enlightening effect can be expected. On the other hand, the need to provide students with experience whenever possible in a limited time was confirmed.

　Purpose：The purpose of this study was to clarify how denture conditions affect the effect of denture adhesive.

　Methods：The subjects were divided into two groups, with 10 subjects in each group. The subjects in group G had good denture retention and stability, whereas the subjects in group P had poor denture retention and stability. Maximum occlusal force, total occlusal force, mastication ability, and QOL（General Oral Health Assessment Index：GOHAI）associated with the oral cavity were measured. For maximum occlusal force, a region corresponding to both sides of the central incisor and first molar of the habitual mastication side was measured as denture retention. For total occlusal force, maximum occlusal force of the entire dentition was measured. For mastication ability, dissolution of glucose was measured by chewing a gummy candy. For QOL（GOHAI）associated with the oral cavity, the subjects were asked to answer 12 questionnaire items.

　Results：Group G showed significantly higher psychosocial and total scores for GOHAI after using the denture adhesive compared to that before using the adhesive. Group P showed significantly higher denture retention for a region corresponding to the central incisor and first molar, total occlusal force, and psychosocial and total scores for GOHAI after using denture adhesive compared to that before using the adhesive.

　Conclusions：Using denture adhesive for dentures with good retention and stability contributed to improving subjective evaluations. For dentures with poor retention and stability, retention, occlusal force, and subjective evaluations improved but no contribution to mastication ability was seen.

　In the early stages after hospital discharge, understanding the patientʼs food style and nutritional status, and evaluating that information to adjust nutritional levels and perform swallowing rehabilitation, are important for continuing home care. We report a case of early nutritional assessment and swallowing rehabilitation for home-care elderly people who have been discharged from hospital after gastrostomy.

　The patient was an 80-year-old man suffering from corticobasal degeneration. Due to his impaired cognitive function, his ability to eat and swallow properly was diminished, leading to aspiration pneumonia. Gastrostomy was performed to ameliorate these issues and he was discharged after the operation. The patient remained bedridden, with communication difficulties, so we carried out home-visit dental treatment. Anthropometric data and blood tests showed slight nutritional disorder, so the patient was instructed to be fed with a high-density liquid diet through the gastric fistula. The patient did not ingest orally at home, so it was decided from the results of a videoendoscopic evaluation of swallowing to improve oral intake as an objective. The patient suffered from wakefulness and found it difficult to sit upright. Due to these factors, the caretaker was given instructions on dysphagia rehabilitation, starting with indirect methods and then gradually integrated direct methods. Through the use of the gastric fistula, the patientʼs nutritional status improved, but his swallowing disorder could not be ameliorated. However, after a nutritional assessment done during home dental care, we surmised that as a result of the indirect and direct swallowing training, the instruction of the caregiver, and the videoendoscopic evaluation, the patientʼs will to eat had improved and there was also a desire to work with the caregiver in continuing the swallowing rehabilitation.

　A 67-year-old man with front temporal dementia（FTD）beginning 3 years prior underwent dental treatment for dental prosthesis repair. He presented with a repetitive jaw tapping movement and repeatedly put candy in his mouth, claiming that the jaw tapping could only be stopped if he had candy in his mouth；hence, he also did not want to take the candy out of his mouth. We decided to perform the required dental treatment for dental prosthesis repair under inhalation sedation with nitrous oxide.

　During the first dental treatment, inhalation sedation was induced by nitrous oxide administered via a nasal cannula. Four minutes later, the anesthesiologist asked the patient to take the candy out of his mouth, to which he complied. The scheduled dental treatment was performed under inhalation sedation without the patient demonstrating continuous jaw tapping. During the subsequent second and third dental treatments, as soon as the anesthesiologist applied the nasal cannula on the patientʼs nose, he took the candy out of his mouth.

　This patient demonstrated compulsive behavior in the form of jaw tapping, which he believed could only be stopped if he had candy in his mouth. Sedation with nitrous oxide inhalation helped to reduce the obsession. FTD patients often exhibit reflex actions in response to external stimuli. In the present case, it is possible that the patient developed a new habit of stopping jaw tapping and not requiring candy when wearing a nasal cannula for the induction of inhalation sedation.

　In conclusion, inhalation sedation with nitrous oxide during dental treatment was useful in reducing our FTD patientʼs obsessive behavior during the treatment.