Relationship between olfactory and gustatory functions: The Iwaki health promotion project 2019.

OBJECTIVE: Olfactory and gustatory functions are important sensory aspects in humans. Although they are believed to influence each other, their interrelationship is not well understood. In this study, we aimed to investigate the relationship between the olfactory and gustatory functions based on the results of a large-scale epidemiological study (Iwaki Health Promotion Project) of the general local population. METHODS: We analyzed 565 participants who underwent taste and olfactory tests in the 2019 Iwaki Project. Gustatory function was tested for four taste qualities (sweet, sour, salty, and bitter) using whole-mouth taste tests. Olfactory function was tested using the University of Pennsylvania Smell Identification Test modified for Japanese (UPSIT-J). We evaluated sex-related differences between olfactory and gustatory functions and the effects of various factors on olfactory identification using multivariate analysis. Furthermore, we compared the percentage of accurate UPSIT-J responses between the normal and hypogeusia groups. We also analyzed the effects of taste and olfactory functions on eating. RESULTS: Olfactory and gustatory functions were lower in men than in women. Among the four taste qualities, salty taste was the most closely associated with olfactory identification ability, with lower olfactory scores of salty taste in the hypogeusia group than in the normal group. Moreover, the hyposmia group had higher daily salt intake than the normal olfaction group in women. CONCLUSION: These results suggest that olfactory identification tests may be useful in predicting elevated salt cognitive thresholds, leading to a reduction in salt intake, which may contribute to hypertension prevention.

Roles of Dental Care in Disaster Medicine in Japan.

Purpose of Review: Natural disasters occur frequently in Japan. A disaster medical system was rapidly developed in Japan following the Great Hanshin-Awaji Earthquake in 1995. Dentistry has become increasingly important in disaster medicine. This review summarizes the roles of dental professionals in disaster medicine, highlights relevant issues, and identifies new directions for research to improve disaster relief activities based on our previous experiences as dental professionals supporting the victims of major disasters. Recent Findings: Many preventable deaths after a disaster are caused by aspiration pneumonia, which occurs against a background of factors that are compounded by a harsh living environment. An important aim of dental care in disaster medicine is to prevent these disaster-related deaths in vulnerable persons such as the elderly. This can be achieved through interventions to maintain oral hygiene, preserve and enhance oral function (i.e., chewing and swallowing), and improve the diet, since these interventions help to prevent the development of malnutrition and frailty in vulnerable people. Dental identification of disaster victims could be improved through the use of intraoral three-dimensional scanners and artificial intelligence to automate the acquisition of dental findings and through the construction of a national database of digitized dental records. Advances in personal identification methods will be needed given the prediction that a catastrophic earthquake will occur on the Nankai Trough during the next 30 years and claim more victims than the 2011 Great East Japan Earthquake. Summary: Disaster-related deaths due to aspiration pneumonia can be prevented by providing appropriate dental care to those in need. The process of identifying victims could be made more efficient through the use of intraoral three-dimensional scanning, artificial intelligence, and a digital database of dental records. Establishing and strengthening relationships between professionals in different regions will help to optimize the multidisciplinary response to future large-scale disasters.

Development of an artificial intelligence-based algorithm to classify images acquired with an intraoral scanner of individual molar teeth into three categories.

BACKGROUND: Forensic dentistry identifies deceased individuals by comparing postmortem dental charts, oral-cavity pictures and dental X-ray images with antemortem records. However, conventional forensic dentistry methods are time-consuming and thus unable to rapidly identify large numbers of victims following a large-scale disaster. OBJECTIVE: Our goal is to automate the dental filing process by using intraoral scanner images. In this study, we generated and evaluated an artificial intelligence-based algorithm that classified images of individual molar teeth into three categories: (1) full metallic crown (FMC); (2) partial metallic restoration (In); or (3) sound tooth, carious tooth or non-metallic restoration (CNMR). METHODS: A pre-trained model was created using oral-cavity pictures from patients. Then, the algorithm was generated through transfer learning and training with images acquired from cadavers by intraoral scanning. Cross-validation was performed to reduce bias. The ability of the model to classify molar teeth into the three categories (FMC, In or CNMR) was evaluated using four criteria: precision, recall, F-measure and overall accuracy. RESULTS: The average value (variance) was 0.952 (0.000140) for recall, 0.957 (0.0000614) for precision, 0.952 (0.000145) for F-measure, and 0.952 (0.000142) for overall accuracy when the algorithm was used to classify images of molar teeth acquired from cadavers by intraoral scanning. CONCLUSION: We have created an artificial intelligence-based algorithm that analyzes images acquired with an intraoral scanner and classifies molar teeth into one of three types (FMC, In or CNMR) based on the presence/absence of metallic restorations. Furthermore, the accuracy of the algorithm reached about 95%. This algorithm was constructed as a first step toward the development of an automated system that generates dental charts from images acquired by an intraoral scanner. The availability of such a system would greatly increase the efficiency of personal identification in the event of a major disaster.

Drinking Ice-Cold Water Reduces the Severity of Anticancer Drug-Induced Taste Dysfunction in Mice.

Taste disorders are common adverse effects of cancer chemotherapy that can reduce quality of life and impair nutritional status. However, the molecular mechanisms underlying chemotherapy-induced taste disorders remain largely unknown. Furthermore, there are no effective preventive measures for chemotherapy-induced taste disorders. We investigated the effects of a combination of three anticancer drugs (TPF: docetaxel, cisplatin and 5-fluorouracil) on the structure and function of mouse taste tissues and examined whether the drinking of ice-cold water after TPF administration would attenuate these effects. TPF administration significantly increased the number of cells expressing apoptotic and proliferative markers. Furthermore, TPF administration significantly reduced the number of cells expressing taste cell markers and the magnitudes of the responses of taste nerves to tastants. The above results suggest that anticancer drug-induced taste dysfunction may be due to a reduction in the number of taste cells expressing taste-related molecules. The suppressive effects of TPF on taste cell marker expression and taste perception were reduced by the drinking of ice-cold water. We speculate that oral cryotherapy with an ice cube might be useful for prophylaxis against anticancer drug-induced taste disorders in humans.

Prevention of postoperative pneumonia by perioperative oral care in patients with esophageal cancer undergoing surgery: a multicenter retrospective study of 775 patients.

PURPOSE: Postoperative pneumonia is one of the major complications after esophageal cancer surgery. The risk factors associated with postoperative pneumonia are poor general health, smoking, decreased pulmonary function, diabetes mellitus, surgical stress, old age, postoperative aspiration, and oral hygiene. In this study, we examined the effect of perioperative oral care on reducing postoperative pneumonia since the evidence to-date is not clear. METHODS: A multicenter, retrospective investigation of the relationship between perioperative oral care and incidence of postoperative pneumonia in patients undergoing esophageal cancer surgery was conducted. A total of 775 patients who underwent thoracoscopic esophageal resection at 25 hospitals between 2016 and 2017 were enrolled in the study. Various factors were examined for correlation with development of postoperative pneumonia. RESULTS: Multivariate analysis showed that old age, smoking habit, lower hemoglobin, higher creatinine, postoperative dysphagia, and lack of oral care intervention were independent risk factors for pneumonia. Oral care was more effective in preventing pneumonia in hospitals in which the incidence of postoperative pneumonia was lower than 20%, while it was not effective in hospitals in which the incidence was higher than 20%. CONCLUSION: Results of the study suggest that it is recommended to carry out perioperative oral care in esophageal cancer surgery.

The development of Ti alloys for dental implant with high corrosion resistance and mechanical strength.

The corrosion behaviors of Ti and Ti-6Al-4V, Ti-6Al-7Nb, Ti-0.5Pt, Ti-6Al-4V-0.5Pt, and Ti-6Al-7Nb-0.5Pt alloys were examined using an electrochemical analyzer in artificial saliva containing 0.1 and 0.2% NaF at a pH of 4.0. The SEM observations revealed that the surfaces of the alloys containing 0.5 wt% Pt were not affected in fluoride-containing environments, whereas the surfaces of Ti, Ti-6A1-4V, and Ti-6Al-7Nb alloys were markedly rough. In artificial saliva containing 0.1% NaF at a pH of 4.0, the amounts of Ti dissolved from the Ti, Ti-6Al-4V, and Ti-6Al-7Nb alloys were about 50 times larger than those of the alloys containing 0.5 wt% Pt. The tensile strengths of the alloys containing 0.5 wt% Pt were equal to or higher than those of pure Ti or the alloys without Pt. The Ti-0.5Pt, Ti-6Al-4V-0.5Pt, and Ti-6Al-7Nb-0.5 alloys are expected to be useful in clinical dentistry as new Ti alloys with high corrosion resistance and mechanical strength.