Exploration of correlation of oral hygiene and condition with influenza infection.

Influenza viruses are known to be infected through epithelial cells of the upper respiratory tract. The oral cavity is in close anatomical proximity to the upper respiratory tract, and it is conceivable that the viruses could pass through the oral cavity and infect to the upper respiratory tract. Several researchers have suggested that colonization of certain pathogenic bacteria such as Staphylococcus aureus or Streptococcus pneumoniae might affect the risk of influenza viral disease, indicating that oral hygiene and/or condition might play an important role in respiratory viral infection. Therefore, the purpose of this study was to investigate whether an oral hygiene/condition might impact influenza infection. We conducted a retrospective observational study of Japanese citizens' regional cohort (N = 2,904) consisting of National Health Insurance beneficiaries who underwent annual health/dental examination with data entries in the Kokuho database (KDB). Trained dentists checked the oral hygiene/condition, and saliva specimens were examined using the LION dental saliva multi-test (SMT) kit. Influenza infection was identified from the diagnosis recorded in the KDB. The correlations between influenza infection and oral hygiene, dryness of the mouth, or various salivary test results were examined by a multivariate analysis adjusting for confounding factors such as gender, age, recent smoking, alcohol drinking, BMI, HbA1c, RBC for influenza infection. The logistic regression model showed that age significantly correlated with influenza infection. In addition, oral hygiene status had a nearly significant impact on influenza infection (p = 0.061), whereby, the subjects with poor oral hygiene had a higher risk of influenza infection than those with good oral hygiene (odds ratio: 1.63, 95% confidence interval: 0.89-2.95). Further, the prevalence of influenza infection was lower in the subjects with saliva weakly acidic and/or containing higher protein level. The results of this study suggested that the maintenance of oral health conditions might be one of the pivotal factors for preventing and reducing influenza infection.

A retrospective investigation of minor risk factors as prognostic predictors and treatment indications in oral squamous cell carcinoma.

Abstract. BACKGROUND/PURPOSE: The clinical significance of minor risk factors remins uncertain in oral squamous cell carcinoma (OSCC) patients. The purpose of this study was to investigate the clinical impact of minor risk factors in OSCC patients. MATERIALS AND METHODS: The cases of OSCC patients that underwent surgery were retrospectively analyzed. Patients with major risk factors for recurrence, such as positive surgical margins or extracapsular spread, were excluded. The impact of possible minor risk factors on treatment outcomes was analyzed. One hundred and seventy-five patients with primary OSCC that underwent surgery were included in this study. RESULTS: The 5-year overall survival (OS), cancer-specific survival (CSS), and relapse-free survival (RFS) rates were 81.2%, 91.0%, and 72.4%, respectively. In multivariate analyses, RFS exhibited a significant association with the pattern of invasion (grade 4 vs. grades 1-3: hazard ratio: 3.096, 95% confidence interval: 1.367-6.884, p < 0.01), OS exhibited a tendency towards associations with the pattern of invasion and perineural invasion, and CSS displayed a tendency towards an association with perineural invasion. The prognosis of the patients with ≥2 minor risk factors was significantly worse than that of the patients with 0 or 1 minor risk factor(s) (OS: 91.6% vs. 64.5%, respectively, p < 0.01; CSS: 98.9% vs. 78.9%, respectively, p < 0.001; and RFS: 81.2% vs. 58.5%, respectively p < 0.05). CONCLUSION: Grade 4 invasion and perineural invasion might be significant minor risk factors in OSCC patients. The presence of ≥2 minor risk factors might be a predictor of a poor prognosis in OSCC patients.