Tongue pressure plays an important role in swallowing function. The purpose of this study is to investigate whether decreased tongue pressure is associated with dysphagia and the development of pneumonia in the elderly requiring long-term care. Tongue pressure measurement and swallowing videoendoscopic (VE) examination were performed in 60 hospitalized elderly people (33 males and 27 females, with an average age of 84.3 years) to investigate the relationship with the clinical course. Factors related with dysphagia was analyzed by Fisher's exact test and one-way ANOVA, followed by multivariate logistic regression. The relationship between each variable and survival were analyzed by cox regression. Twenty-one patients had dysphagia by VE examination. Multivariate analysis showed that smaller BMI and reduced tongue pressure were significantly correlated with dysphagia. Smaller number of remaining teeth and dysphagia were significantly related to pneumonia-related death. No patients with tongue pressure of larger than 20 kpa died by pneumonia within one year, while in those with tongue pressure of smaller than 20 kpa, one-year cumulative survival rate by pneumonia was 44.3%. Decreased tongue pressure was significantly associated with dysphagia and may increase the risk of pneumonia-related death in the elderly requiring long-term care.

Osteoradionecrosis of the jaw (ORN) often occurs in patients with head and neck cancer undergoing radiotherapy (RT). It has been recommended to extract the tooth before RT that may become source of infection, but in recent years, some investigators have reported that tooth extraction before RT increase the risk of developing ORN and therefore should be avoided. The purpose of the study is to evaluate the risk factors for ORN including tooth extraction before RT. This was a retrospective study of 366 patients with oral or oropharyngeal cancer who underwent RT of 50 Gy or more at six university hospitals, with follow-up of at least six months post-RT. The relationship between each factor and ORN incidence was analyzed using the Cox proportional hazard model. Periapical lesions, more than 50% loss of alveolar bone, and tooth extraction after RT significantly correlated with ORN. Intensity-modulated RT showed a lower incidence than three-dimensional conformal RT, although not statistically different. Tooth extraction before RT significantly reduced ORN incidence, after adjusting the background factors using propensity score matching. In patients with oral or oropharyngeal cancer who underwent RT, periapical lesions, more than 50% loss of alveolar bone, and tooth extraction after RT significantly increased the risk for ORN. Infected tooth extraction before RT significantly reduced the risk.

Increased amount of tongue coating has been reported to be associated with increased bacteria count in the saliva and aspiration pneumonia in elderly people. However, the implications of tongue coating for prevention of postoperative complications in patients undergoing major oncologic or cardiac surgery has not been well documented. The purpose of this study is to investigate the number of bacteria on the tongue before and after surgery and factors affecting it. Fifty-four patients who underwent oncologic or cardiac surgery under general anesthesia at Nagasaki University Hospital were enrolled in the study. Various demographic, tumor-related, treatment-related factors, and the number of bacteria on the tongue and in the saliva were examined, and the relationship among them was analyzed by Mann-Whitney U test, Spearman rank correlation coefficient, or multiple regression. Before surgery, no significant factors were correlated with the number of bacteria on the tongue, and there were no relationship between bacteria count on the tongue and that in the saliva. On the next day after surgery, bacteria on the tongue increased, and sex, periodontal pocket depth, feeding condition, dental plaque, blood loss, and bacteria in the saliva were correlated with bacteria on the tongue by a univariate analysis. A multivariate analysis showed that feeding condition, and amount of dental plaque were correlated with the number of bacteria. Increased number of bacteria on the tongue was associated with feeding condition and amount of dental plaque. Further studies are necessary to clarify the clinical significance of dental coating in perioperative oral management of patients undergoing oncologic or cardiac surgery.

Background: Oral care is important in preventing aspiration pneumonia in older adults. However, it is not clear what kind of oral care can reduce the number of bacteria in saliva. The purposes of this study are to clarify whether there is a relationship between plaque amounts and salivary bacterial counts, and how bacteria dispersed into the oral cavity by brushing can be reduced. Methods: First, saliva samples were collected from 10 healthy adult volunteers after 30 h of unbrushing and after thorough brushing, and the total bacterial count was determined by real-time PCR. Next, 40 older adults attending an outpatient dental clinic were randomly assigned into two groups: a wiping group (20 patients) and a mouthwashing group (20 patients). Saliva was collected before and after brushing, and after wiping in the wiping group and after mouthwashing in the mouthwashing group, and the total bacterial count was quantified by real-time PCR. Results: In a study of volunteers, there was no association between plaque amounts and salivary bacterial counts. In a study of older adult patients, salivary bacterial counts were significantly higher in patients with higher oral hygiene index and fewer remaining teeth. Brushing increased salivary bacterial counts. Wiping did not significantly reduce the number of bacteria, while mouthwash returned the increased number of bacteria after brushing to the pre-brushing level. Conclusions: There is no direct relationship between the amount of plaque and the number of bacteria in saliva. Brushing disperses bacteria into the oral cavity, resulting in a marked increase in the number of bacteria in saliva. Wiping does not collect the dispersed bacteria, and it seems essential to rinse the mouth after brushing. Trial registration: UMIN000045854.

Introduction: Aspiration pneumonia, an important issue for the older adults, is caused by an increase in pathogenic microorganisms in the saliva, aspiration, and weakened host immunity. Recently, decreased tongue pressure has been reported to be associated with dysphagia. This study aimed to investigate the relationship between decreased tongue pressure and the number of bacteria in the saliva of the older adults requiring long-term care. Methods: This cross-sectional study involved 95 older adults requiring long-term care in a facility or at home, eating orally, and who could understand the instructions for measuring tongue pressure. Sex, age, slowness, weakness, shrinking, exhaustion, low activity, number of teeth, functional teeth unit, denture use, oral hygiene, tongue coating index, dry mouth, tongue pressure, and number of bacteria in the saliva were examined. Bacterial counts were analyzed by real-time PCR for total bacteria, total streptococci, methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, Porphyromonas gingivalis, and Candida albicans. Results: Multiple regression analysis showed that poor oral hygiene and decreased tongue pressure were independent risk factors for increased bacteria in the saliva. Decreased tongue pressure is significantly correlated with an increased number of total bacteria and the presence of P. gingivalis. Discussion/Conclusion: Our results suggest that tongue pressure not only maintains the swallowing function but also prevents the increase of bacteria in the saliva of older adults requiring long-term care.

Perioperative oral management is performed to prevent postoperative complications, but its indication and management method are unclear. This study aimed to investigate salivary bacterial counts pre-and postoperatively, and factors related to increased bacterial count postoperatively. We included 121 patients who underwent surgery under general anesthesia and perioperative oral management. The bacterial count in saliva was determined preoperatively, and first and seventh days postoperatively using the dielectrophoresis and impedance measurement methods. The relationships between salivary bacterial count and various variables were analyzed using one-way analysis of variance, Spearman’s rank correlation coefficient, and multiple regression analysis. The salivary bacterial count increased significantly on the first day postoperatively but decreased on the seventh day. Multivariate analysis showed that age (p = 0.004, standardized coefficient β = 0.283) and xerostomia (p = 0.034, standardized coefficient β = 0.192) were significantly correlated with increased salivary bacterial count preoperatively. Salivary bacterial count on the day after surgery was significantly increased in patients with a large number of bacterial counts on the day before surgery after preoperative oral care (p = 0.007, standardized coefficient β = 0.241) and postoperative fasting (p = 0.001, standardized coefficient β = −0.329). Establishing good oral hygiene before surgery and decreasing salivary bacterial count are necessary in patients with a high risk of postoperative surgical site infection or pneumonia, especially in older adults or postoperative fasting.