Investigating the association between oral hygiene and head and neck cancer

Metagenomic shotgun sequencing reveals the enrichment of Salmonella and Mycobacterium in larynx due to prolonged ethanol exposure

The exposure of ethanol increases the risk of head and neck inflammation and tumor progression. However, limited studies have investigated the composition and functionality of laryngeal microbiota under ethanol exposure. We established an ethanol-exposed mouse model to investigate the changes in composition and function of laryngeal microbiota using Metagenomic shotgun sequencing. In the middle and late stages of the experiment, the laryngeal microbiota of mice exposed to ethanol exhibited obvious distinguished from that of the control group on principal-coordinate analysis (PCoA) plots. Among the highly abundant species, Salmonella enterica and Mycobacterium marinum were likely to be most impacted. Our findings indicated that the exposure to ethanol significantly increased their abundance in larynxes in mice of the same age, which has been confirmed through FISH experiments. Among the species-related functions and genes, metabolism is most severely affected by ethanol. The difference was most obvious in the second month of the experiment, which may be alleviated later because the animal established tolerance. Notable enrichments concerning energy, amino acid, and carbohydrate metabolic pathways occurred during the second month under ethanol exposure. Finally, based on the correlation between species and functional variations, a network was established to investigate relationships among microbiota, functional pathways, and related genes affected by ethanol. Our data first demonstrated the continuous changes of abundance, function and their interrelationship of laryngeal microbiota under ethanol exposure by Metagenomic shotgun sequencing.

Importance

Ethanol may participate in the inflammation and tumor progression by affecting the composition of the laryngeal microbiota. Here, we applied the metagenomic shotgun sequencing instead of 16 S rRNA sequencing method to identify the laryngeal microbiota under ethanol exposure. Salmonella enterica and Mycobacterium marinum are two dominant species that may play a role in the reconstruction of the laryngeal microenvironment, as their local abundance increases following exposure to ethanol. The metabolic function is most evidently impacted, and several potential metabolic pathways could be associated with alterations in microbiota composition. These findings could help us better understand the impact of prolonged ethanol exposure on the microbial composition and functionality in the larynx.

Establishment of a prognostic model for hypoxia-associated genes in OPSCC and revelation of intercellular crosstalk

Hypoxia exerts a profound influence on the tumor microenvironment and immune response, shaping treatment outcomes and prognosis. Utilizing consistency clustering, we discerned two hypoxia subtypes in OPSCC bulk sequencing data from GEO. Key modules within OPSCC were identified through weighted gene correlation network analysis (WGCNA). Core modules underwent CIBERSORT immune infiltration analysis and GSEA functional enrichment. Univariate Cox and LASSO analyses were employed to construct prognostic models for seven hypoxia-related genes. Further investigation into clinical characteristics, the immune microenvironment, and TIDE algorithm prediction for immunotherapy response was conducted in high- and low-risk groups. scRNA-seq data were visually represented through TSNE clustering, employing the scissors algorithm to map hypoxia phenotypes. Interactions among cellular subpopulations were explored using the Cellchat package, with additional assessments of metabolic and transcriptional activities. Integration with clinical data unveiled a prevalence of HPV-positive patients in the low hypoxia and low-risk groups. Immunohistochemical validation demonstrated low TDO2 expression in HPV-positive (P16-positive) patients. Our prediction suggested that HPV16 E7 promotes HIF-1α inhibition, leading to reduced glycolytic activity, ultimately contributing to better prognosis and treatment sensitivity. The scissors algorithm effectively segregated epithelial cells and fibroblasts into distinct clusters based on hypoxia characteristics. Cellular communication analysis illuminated significant crosstalk among hypoxia-associated epithelial, fibroblast, and endothelial cells, potentially fostering tumor proliferation and metastasis.

Periodontitis and the risk of oral cancer: a meta-analysis of case-control studies

OBJECTIVE

The current studies have yielded inconclusive findings regarding the connection between periodontitis  and oral cancer (OC). Therefore, our goal is to elucidate this relationship.

MATERIALS AND METHODS

We conducted a thorough search of electronic databases (EMBASE, PubMed, Web of Science, and Cochrane Library) up to September 2023. The Newcastle-Ottawa Scale (NOS) was applied to assess study quality. To evaluate potential publication bias, both a funnel plot and Egger's test were employed. Additionally, a sensitivity analysis was conducted to explore the source of heterogeneity when the I2 statistic exceeded 50%.

RESULTS

This systematic review encompassed 16 studies, involving a total of 6,032 OC patients and 7,432 healthy controls. Our meta-analysis, incorporating data from nine studies, revealed a significant correlation between periodontitis and the risk of OC (OR [odds ratio] = 2.94, 95% CI [confidence interval] (2.13, 4.07); five studies, 6,927 participants; low certainty of evidence). Findings also suggested that individuals with more than 15 missing teeth may have a heightened risk of OC (OR = 1.91, 95% CI (1.01, 3.62)). Furthermore, clinical attachment loss (CAL) and decayed, missing, and filled teeth (DMFT) in OC patients were more pronounced compared to the control group (CAL, SMD = 1.94, 95% CI (0.22, 3.66); DMFT, SMD = 0.65, 95% CI (0.12, 1.18)).

CONCLUSION

Periodontitis may serve as a potential risk factor for OC. However, caution is warranted in interpreting these findings due to the substantial level of heterogeneity.

Oral health in patients with different sites of head and neck squamous cell carcinoma is not different

Oral health might not only act as risk factor for head and neck squamous cell carcinoma (HNSCC), but might also have a predictive value for the patients' survival. Currently, information on the effect of oral health on survival of patients with different sites of HNSCC is lacking. This single-center retrospective study aimed to compare oral health in patients with different sites of HNSCC and to analyse whether oral health is associated with survival in the different subsets of HNSCC patients. Dental records of HNSCC patients referred for dental assessment prior to radio(chemo)therapy were included. Patient-related parameters (age at time of diagnosis, sex, tobacco exposure, alcohol consumption, HPV status), treatment data (primary treatment, intent), performance status, tumor demographics (anatomical site, TNM staging), and oral health parameters (DMFT, periodontal health, teeth with/without root canal treatment and with/without periodontitis apicalis) were obtained. Oral health parameters were compared between different anatomical sites. Survival of all HNSCC patients and of individual subsets was assessed using Kaplan-Meier statistics, and the effect of tumor demographics, patient-related parameters, and oral health on survival was analysed by cox regression analyses (α = 5%). 371 patients with HNSCC (oral: n = 86, oropharyngeal: n = 174, hypopharyngeal: n = 59, laryngeal: n = 15, other: n = 37) were included. Oral health parameters did not differ between subsets (padj.≥0.199). Five-year cumulative survival of HNSCC patients amounted to 78.6%. Only for HNSCC originating in the oral cavity and oropharynx, survival was associated with the treatment intent (p = 0.015) or performance status (p = 0.007) in the multivariable analyses, respectively. Within the limitations of this study, oral health was not different between different subsets and had no significant effect on survival of HNSCC patients.

The association between oral hygiene and head and neck cancer: a meta-analysis

OBJECTIVE

Oral hygiene has been suspected to contribute to the aetiology of head and neck cancer (HNC). Based on the meta-analysis, we evaluated the impact of oral hygiene on head and neck cancer (HNC) and its survival.

MATERIALS AND METHODS

Relevant case-control and cohort studies reporting survival data, oral hygiene data were searched via PubMed, Embase, Cochrane Library, and Web of Science databases. The odds ratios (ORs), hazard ratios (HRs), and 95% confidence intervals (CIs) were used. Subgroup analysis was performed.

RESULTS

Oral hygiene was associated with HNC. Tooth brushing ≥2 a day, dental floss use, denture wearing, caries ≥3, and dental visit ≥1 reduced the risk of oral cavity cancer while mouth wash use, missing teeth >5, gum bleeding, and periodontal disease increased the risk of oral cavity cancer. For oropharynx cancer, tooth brushing ≥2 and caries ≥3 were associated with reduced risk of it. Tooth brushing ≥2 and dental visits ≥1 decreased the risk of pharynx cancer risk and larynx cancer risk, however, missing teeth >5 increased both of them.

CONCLUSION

Oral hygiene was associated with HNC and its sub sites. Oral hygiene should be strengthened, a dental floss use and dentist's visits can be recommended.

The Influence of the Oral Microbiome on Oral Cancer: A Literature Review and a New Approach

In our recent article (Smędra et al.: Oral form of auto-brewery syndrome. J Forensic Leg Med. 2022; 87: 102333), we showed that alcohol production can occur in the oral cavity (oral auto-brewery syndrome) due to a disruption in the microbiota (dysbiosis). An intermediate step on the path leading to the formation of alcohol is acetaldehyde. Typically, acetic aldehyde is transformed into acetate particles inside the human body via acetaldehyde dehydrogenase. Unfortunately, acetaldehyde dehydrogenase activity is low in the oral cavity, and acetaldehyde remains there for a long time. Since acetaldehyde is a recognised risk factor for squamous cell carcinoma arising from the oral cavity, we decided to analyse the relationship linking the oral microbiome, alcohol, and oral cancer using the narrative review method, based on browsing articles in the PubMed database. In conclusion, enough evidence supports the speculation that oral alcohol metabolism must be assessed as an independent carcinogenic risk. We also hypothesise that dysbiosis and the production of acetaldehyde from non-alcoholic food and drinks should be treated as a new factor for the development of cancer.

A Systematic Review and Meta-Analysis Assessing the Role of Oral Health as a Risk Factor in Oral Cancer

Oral squamous cell carcinoma is the leading type of cancer in Southeast Asian countries and many parts of the world. Many factors increase the risk of oral cancer, like tobacco, betel nuts, alcohol consumption, sharp teeth, infections, and other factors. Oral health-related issues have been reported in many studies of oral cancer, but there is a need to understand the role of the same as a risk factor. The systematic review and meta-analysis were conducted to assess the role of oral health as a risk factor in oral cancer. The population diagnosed with oral cancer (P) of all age groups and both gender, exposure (E) is oral health (includes poor oral hygiene, periodontal disease, and other oral diseases excluding oral potentially malignant disorders (OPMD)), the comparator (C), is patients without oral health issues, outcome (O) is the role of poor oral health as a risk factor for oral cancer. A systematic review and meta-analysis were conducted. The databases used for the search were PubMed, Cochrane Database, Embase, Scopus, and Google Scholar. The unpublished reports, reviews, and grey literature were considered. Case-control studies were included assessing poor oral health as a risk factor with odds ratio as an effective measure. Newcastle Ottawa Scale for risk of bias in the case-control study was considered. The study results showed that tooth loss odds ratio (OR)=1.13, CI (0.99-1.26), I² value of 71.7%, Oral hygiene OR=1.29, CI (1.04-1.54), I² value of 19.7% and in periodontal diseases OR=2.14 CI (1.70-2.58), I² value of 75.3% had a higher risk of developing oral cancer. The risk factors for tooth loss and periodontal disease showed moderate heterogenicity and less heterogenicity for oral hygiene. Poor oral health factors such as periodontal disease, poor oral hygiene, and loss of teeth show higher odds of oral cancer than the control. The periodontal disease shows the highest odds than other factors. These risk factors can be considered for the primordial prevention of oral cancer.

Bibliometric Analysis of Poor Oral Health as a Risk Factor for Oral Cancer

Poor oral health is a risk factor for oral cancer, and bibliometrics can tell us important things about publication trends and research. Oral cancer risk factors include smoking, betel nut chewing, alcohol consumption, trauma from sharp teeth, chronic infections, and other factors related to oral health. There is a need to understand the role of poor oral health as a risk factor. Thus, this study aimed to conduct a bibliometric analysis of the literature on poor oral health as a risk factor for oral cancer. A bibliometric analysis was conducted for poor oral health as a risk factor for oral cancer using RStudio 2021.09.0+351 "Ghost Orchid" Release (2021-09-20) for Windows, package "bibliometrix." The literary data for this study were derived from Elsevier's Scopus database, and the data were exported in BibTex format. The results considered the time frame of 1983 to 2022, with journals, books, newspaper articles, and others as sources, accounting for a total of 543 documents. The search yielded a total of 2,882 authors, with a total of 3,306 appearances. The results show that the research on poor oral health and oral cancer is mainly led by the United States (106), India (49), and China (46). The top author is Warnakulasuriya S, followed by Worthington HV. The research shows the countries that are currently working on the topics and helps set up future collaborations to improve the evidence produced and help the scientific community by finding research gaps and experts in this area of research.

The Oral Microbiome as Mediator between Oral Hygiene and Its Impact on Nasopharyngeal Carcinoma

Oral hygiene and the alteration of the oral microbiome have been linked to nasopharyngeal carcinoma (NPC). This study aimed to investigate whether the oral microbiome plays a mediating role in the relationship between oral hygiene and NPC, and identify differential microbial taxonomies that potentially mediated this association. We conducted a case–control study that involved 218 NPC patients and 192 healthy controls. The 16S rRNA gene sequencing of the V4 region was performed to evaluate the composition of the oral microbiome. Mediation analysis was applied to explore the relationship among oral hygiene, the oral microbiome and NPC. We found that dental fillings and poor oral hygiene score were associated with increased risks of NPC (OR = 2.51 (1.52–4.25) and OR = 1.54 (1.02–2.33)). Mediation analysis indicated that dental fillings increased the risk of NPC by altering the abundance of Erysipelotrichales, Erysipelotrichaceae, Solobacterium and Leptotrichia wadei. In addition, Leptotrichia wadei also mediated the association between oral hygiene score and the risk of NPC. Our study confirmed that poor oral hygiene increased the risk of NPC, which was partly mediated by the oral microbiome. These findings might help us to understand the potential mechanism of oral hygiene influencing the risk of NPC via the microbiome.

Oral health in HPV-positive and HPV-negative patients with oropharyngeal squamous cell carcinoma

This study compared oral health in oropharyngeal squamous cell carcinoma (OPSCC) patients with positive or negative human papillomavirus (HPV) status and analysed whether oral health was associated with survival. Patients referred for dental assessment prior to radio(chemo)therapy between 2009 and 2019 were included. Patient-related risk factors for OPSCC (alcohol, tobacco, HPV status), age, sex, treatment (primary treatment, intent), performance status, tumor/node/metastasis (TNM) staging, and oral health parameters (DMFT, periodontal status, teeth with/without root canal treatment and with/without periodontitis apicalis) were compared between HPV-negative and HPV-positive patients. Survival was assessed using Kaplan-Meier statistics. The effect of patient-related risk factors and oral health parameters was analysed by cox regression analyses (α=5%). A total of 119 patients (n=50 HPV-negative, n=69 HPV-positive) was included. HPV-positive patients showed more present teeth, a higher number of filled teeth, were less often edentulous and presented a lower DMFT compared to HPV-negative patients (p_adj.≤0.003). Among dentulous patients, HPV-positive patients showed more present teeth and fewer teeth with periodontitis apicalis lacking a root canal treatment (p_adj.≤0.036). Survival probability differed between groups (p=0.006) and trended towards being associated with HPV status, tobacco exposure, performance status, T stage, N stage, and the number of missing or filled teeth as well as the number of root canal treated teeth with periodontitis apicalis and the number of teeth with periodontitis apicalis lacking a root canal treatment (p≤0.077). However, only tobacco exposure, performance status, and the number of teeth with periodontitis apicalis lacking a root canal treatment in dentulous patients remained significant in the multivariate analyses (p≤0.047). HPV-negative patients with OPSCC showed a poorer oral health compared to HPV-positive patients, but survival was not associated with oral health.

Dental health in patients with and without HPV-positive oropharyngeal and tongue cancer

Background

Human papilloma virus is associated with oral and oropharyngeal cancer. Our aim was to examine oral health in patients with oropharyngeal (OPSCC) and oral tongue cancer (OTSCC), expecting better oral health among OPSCC patients.

Material and methods

Fifty-five OPSCC patients with known HPV status and 59 OTSCC patients were randomly selected from a list of consecutive patients of the Helsinki University Hospital, Finland. Oral health was assessed from panoramic jaw radiographs. Total Dental Index (TDI) summarizing the dental health status was calculated and Finnish population study data were used for comparison. Descriptive statistics were used for analyses.

Results

Patients with HPV-positive OPSCC had higher periapical lesion index compared with HPV-negative OPSCC patients or with OTSCC patients. Residual roots were more common among OPSCC patients compared with OTSCC patients, because of their higher occurrence among HPV-negative OPSCC patients compared with OTSCC patients. Similarly, modified TDI score was significantly higher among OPSCC patients than among OTSCC patients, because of higher TDI score among HPV-negative OPSCC patients compared with OTSCC patients. OPSCC patients more often used a removable prosthesis than OTSCC patients. Dental health of the cancer patients was poorer when compared with the population data.

Conclusions

Our study hypothesis was only partly confirmed. Periapical lesions were more prevalent among HPV-positive OPSCC patients, compared with the other groups. The number of residual roots was higher among HPV-negative subgroup. Thus, OPSCC patients had worse oral health parameters than OTSCC patients.

Dental management before radiotherapy of the head and neck region: 4-year single-center experience

OBJECTIVE

To review our experience with a standardized dental management approach in patients with planned radiotherapy of the head and neck region based on preradiation and follow-up data.

MATERIAL AND METHODS

Records of patients who underwent radiotherapy between June 2016 and November 2020 were reviewed. Data on dental findings and therapeutic recommendations were extracted from a prospectively managed database. Hospital records were used to obtain follow-up data.

RESULTS

Two hundred eighty-one patient records were identified. After the exclusion of 81 patients because of incomplete data, 200 patients were included in the study. Dental findings relevant to radiotherapy were found in 144 cases (72.0%). Teeth extractions were recommended in 112 (56.0%) patients. Follow-up data were available for 172 (86.0%) patients (mean follow-up: 16.8 ± 10.7 months). Radiodermatitis was the most frequently observed sequela of radiotherapy (42.4%), followed by dysphagia (38.4%) and stomatitis (36.6%). Osteoradionecrosis was observed in only 2.3% of the patients.

CONCLUSION

Dental findings relevant to planned radiotherapy were frequent and in many cases resulted in recommendations for teeth extraction. Based on our standardized dental management protocol, we observed low rates of late oral complications after radiotherapy of the head and neck region.

Do cutaneous human papillomavirus genotypes affect head and neck cancer? Evidence and bias-correction from a case-control study

BACKGROUND

Three genera of human papillomavirus (HPV) infect the oral cavity and oropharynx- alpha (α), beta (β) and gamma (γ). While α-HPV infection is an established risk factor for head and neck cancers (HNC), the role of other genera remains unclear. We aimed to estimate the effect of α-, β-, γ-HPV on HNC using a hospital-based case-control study.

METHODS

We recruited incident HNC cases (396) and controls (439), frequency-matched by age and sex from four main referral hospitals in Montreal, Canada. We collected information on sociodemographic and behavior characteristics using in-person interviews, and tested rinse, brush and tumor specimens for HPV genotypes. We estimated adjusted odds ratios (aOR) and 95% confidence intervals (CI) for the effect of HPV on HNC using logistic regression, adjusting for confounding. We conducted probabilistic bias analysis to account for potential exposure misclassification, selection bias, and residual confounding.

RESULTS

α-HPV genus had a strong effect on HNC, particularly HPV16 (aOR=22.6; 95% CI: 10.8, 47.2). β-HPV was more common among controls (aOR=0.80; 95% 0.57, 1.11). After adjustment for HPV16, we found weaker evidence for γ-HPV (aOR= 1.29; 95% CI: 0.80, 2.08). Combined bias analyses for HPV16 increased the strength of the point estimate, but added imprecision (aOR=54.2, 95% CI: 10.7, 385.9).

CONCLUSIONS

α-HPV, especially HPV16, appears to increase the risk for HNC, while there is little evidence for an effect of β- or γ-HPV. β-HPV may have a preventive effect, while γ-HPV may increase the risk of HNC, although to a lesser extent than that of α-HPV. Results for cutaneous HPV were imprecise and less conclusive. Due to possible epidemiologic biases, the true relation between HPV and HNC could be underestimated in the literature. Further improvement in current methods and more studies of the biologic mechanisms of the three genera in HNC development are warranted.

Clinical Condition of the Oral Cavity in the Adult Polish Population below 70 Years of Age after Myocardial Infarction-A Case-Control Study

According to recent scientific consensus, there is an increasing amount of evidence on the correlation between oral health and cardiovascular disease morbidity. The aim of the present study was to investigate the number of missing teeth, the presence of residual roots with necrotic pulp and teeth with caries, the type of teeth deficiencies, and periodontal status in patients after myocardial infarction (MI). A total of 151 patients after MI and 160 randomly selected controls without history of MI were enrolled in the study. Epidemiological data were collected, and dental examination was performed. Findings showed significantly more women, subjects with lower level of education, lower income, higher percentage of nicotine addiction, more frequent presence of arterial hypertension, diabetes, and obesity than in the study group. Moreover, oral status of the subjects who suffered from MI was inferior to the control group. An average patient from the study group had 11 missing teeth, when compared to four missing teeth in an average control subject (p < 0.0001). The majority of patients in the control group had occlusal contacts in intercuspal position in premolars and molars (group A), in contrast to the patients after MI, who had at least one missing supporting zone (group B) (p < 0.0001). Severe periodontitis was found in 50.3% of tests and in 30.4% of controls (p < 0.0001). A correlation was found between the edentulousness and the risk of myocardial infarction after adjusting for other known risk factors of cardiovascular diseases (OR = 3.8; 95% CI = 3.01−7.21; p < 0.0001). This case−control study showed that MI patients had more missing teeth, more residual roots with necrotic pulp, much higher incidence of edentulism and occlusal contacts in intercuspal position in fewer than four occlusal supporting zones, as well as worse periodontal status when compared to healthy subjects without a history of MI. Due to the methodology of unmatched controls, the presented results must be interpreted with caution.

Predictive Factors in the Appearance and Evolution of Squamous Cell Carcinomas of the Oral Cavity

Background: Oral squamous cell carcinoma (OSCC) registered an alarming fall in the average age of individuals diagnosed in the last decade. Objectives: The aim of our study is to assess the main risk factors for OSCC specific to Romania and to identify patients at risk for this pathology. The purpose is to implement in the future a screening and early diagnosis program for OSCC in our country. Materials and Methods: A ten-year case-control study was conducted on patients selected from “St. Spiridon” Hospital-Iaşi, Romania. The study contained 1780 individuals diagnosed with oral squamous cell carcinoma. Results: For the patients under 46 years old: APC = −2.8 percent (95% CI: −24.4 to −7.1; p = 0.0012), with the observed rate of 30.18 percent. The incidence increased in patients aged 46 to 49 years (APC = 9.6%; 95% CI: 6.7 to −10.4; p = 0.0081). For the age group 49 to 64 years old: APC = −2.4 percent (95% CI: −5.3 to −1.6, p = 0.1239). For the age group 64–74: APC = −4.6, (95% CI: 1.4 to 6.9, p = 0.0108). The incidence of incidents was lower in the age group 74–80 (p = 0.0025). For the age group 80–91: APC = 8.1 (95% CI: 6.4 to 14.2, p = 0.0024), with the incidence of cases: APC = 8.1 (95% CI: 6.4 to 14.2, p = 0.0024). Univariate analysis revealed a substantially higher risk of developing oral carcinoma in males (OR = 4.43; CI: 3.84 to 5.80). Age above 60, cigarette usage and alcohol abuse are significant risk factors for OSCC. Patients with lymph node dissemination, ulcero-vegetant form, stages II and IV, whose therapeutic approach consisted of radiotherapy and chemotherapy or radiotherapy only had a worse rate of survival at 24 months post-therapy. Conclusions: Our study highlights the increase in the incidence of OSCC in Romania during the research period, the decrease in the average age of diagnosed patients, as well as the degree to which the studied population is exposed to the main risk factors specific to this geographical area.

Oral health indicators as a predictive factor for the quality of life among head and neck cancer patients in Gujarat in India

Aim: The aim of this study was to assess the magnitude of various oral health indicators. Further, to identify the oral health indicators as a predictive factor for the quality of life among head and neck cancer patients. Methods: A cross-sectional study was conducted among 400 head and neck cancer patients attending tertiary cancer center. The European Organization for Research and Treatment of Cancer and Head and Neck specific (EORTCQLQH&N35) module was used to assess the patient's quality of life. Oral health indicators (oral hygiene practices, oral complication, dental visits, oral rehabilitation) were recorded through oral examination and personal interviews. Spearman's correlation coefficient was used to assess the correlation between oral health indicators and different scales of QoL. Multivariate linear regression by a backward stepwise method was applied to assess the influence of oral health indicators as a predictive factor for QoL. Results: Out of 400 patients, 54.25% of patients reported having one or another form of oral complication. Periodontal problems were the common oral complication among the patients. There was a weak correlation between oral health indicators and most of the scales of EORTC QLQ-H&N35. Theoretically, linked oral health indicators were found to be significant predictive factors. Conclusion: The results show that there was a high magnitude of poor oral health indicators. Oral health indicators also acted as a significant predictor of quality of life. A multi-disciplinary approach is desirable for the improvement in oral health thus improving the overall quality of life among head and neck cancer patients.

Head and Neck Squamous Cell Carcinoma: Risk Factors, Molecular Alterations, Immunology and Peptide Vaccines

Head and neck squamous cell carcinoma (HNSCC) arises from the epithelial lining of the oral cavity, hypopharynx, oropharynx, and larynx. There are several potential risk factors that cause the generation of HNSCC, including cigarette smoking, alcohol consumption, betel quid chewing, inadequate nutrition, poor oral hygiene, HPV and Epstein–Barr virus, and Candida albicans infections. HNSCC has causative links to both environmental factors and genetic mutations, with the latter playing a more critical role in cancer progression. These molecular changes to epithelial cells include the inactivation of cancer suppressor genes and proto-oncogenes overexpression, resulting in tumour cell proliferation and distant metastasis. HNSCC patients have impaired dendritic cell (DC) and natural killer (NK) cell functions, increased production of higher immune-suppressive molecules, loss of regulatory T cells and co-stimulatory molecules and major histocompatibility complex (MHC) class Ι molecules, lower number of lymphocyte subsets, and a poor response to antigen-presenting cells. At present, the standard treatment modalities for HNSCC patients include surgery, chemotherapy and radiotherapy, and combinatorial therapy. Despite advances in the development of novel treatment modalities over the last few decades, survival rates of HNSCC patients have not increased. To establish effective immunotherapies, a greater understanding of interactions between the immune system and HNSCC is required, and there is a particular need to develop novel therapeutic options. A therapeutic cancer vaccine has been proposed as a promising method to improve outcome by inducing a powerful adaptive immune response that leads to cancer cell elimination. Compared with other vaccines, peptide cancer vaccines are more robust and specific. In the past few years, there have been remarkable achievements in peptide-based vaccines for HNSCC patients. Here, we summarize the latest molecular alterations in HNSCC, explore the immune response to HNSCC, and discuss the latest developments in peptide-based cancer vaccine strategies. This review highlights areas for valuable future research focusing on peptide-based cancer vaccines.

Associations of toothbrushing behaviour with risks of vascular and nonvascular diseases in Chinese adults

Accumulating evidence has shown that poor oral hygiene is associated with increased risk of cardiometabolic diseases in Western populations. However, its relevance about the relationships in Chinese adults remains unclear. The China Kadoorie Biobank enrolled 512 715 adults aged 30-79 years in China during 2004-2008. Cox regression was used to estimate adjusted hazard ratios (HRs) for each disease associated with measures of oral hygiene. Overall 9.3% of the participants reported rarely or never brushing teeth at baseline. Participants who rarely or never brushed teeth had adjusted HR of 1.12 (95% CI: 1.09, 1.15) for MVE, with similar HRs for stroke (1.08, 1.05-1.12), intracerebral haemorrhage (1.18, 1.11-1.26) and pulmonary heart disease (1.22, 1.13-1.32) compared with those who brushed teeth regularly. Those who did not brush teeth also had increased risk of cancer (1.09, 1.04-1.14), chronic obstructive pulmonary disease (COPD) (1.12, 1.05-1.20), liver cirrhosis (1.25, 1.09-1.44) and all-cause death (1.25, 1.21-1.28) but not type 2 diabetes (0.94, 0.86-1.03) and chronic kidney disease (0.98, 0.81-1.18). Among Chinese adults, we found that poor oral hygiene is associated with higher risks of major vascular disease, cancer, COPD, liver cirrhosis and all-cause deaths, but not type 2 diabetes and chronic kidney disease.

Is There an Interplay between Oral Microbiome, Head and Neck Carcinoma and Radiation-Induced Oral Mucositis?

Head and neck carcinoma is one of the most common human malignancy types and it ranks as the sixth most common cancer worldwide. Nowadays, a great potential of microbiome research is observed in oncology-investigating the effect of oral microbiome in oncogenesis, occurrence of treatment side effects and response to anticancer therapies. The microbiome is a unique collection of microorganisms and their genetic material, interactions and products residing within the mucous membranes. The aim of this paper is to summarize current research on the oral microbiome and its impact on the development of head and neck cancer and radiation-induced oral mucositis. Human microbiome might determine an oncogenic effect by, among other things, inducing chronic inflammatory response, instigating cellular antiapoptotic signals, modulation of anticancer immunity or influencing xenobiotic metabolism. Influence of oral microbiome on radiation-induced oral mucositis is expressed by the production of additional inflammatory cytokines and facilitates progression and aggravation of mucositis. Exacerbated acute radiation reaction and bacterial superinfections lead to the deterioration of the patient's condition and worsening of the quality of life. Simultaneously, positive effects of probiotics on the course of radiation-induced oral mucositis have been observed. Understanding the impact on the emerging acute radiation reaction on the composition of the microflora can be helpful in developing a multifactorial model to forecast the course of radiation-induced oral mucositis. Investigating these processes will allow us to create optimized and personalized preventive measures and treatment aimed at their formation mechanism. Further studies are needed to better establish the structure of the oral microbiome as well as the dynamics of its changes before and after therapy. It will help to expand the understanding of the biological function of commensal and pathogenic oral microbiota in HNC carcinogenesis and the development of radiation-induced oral mucositis.

Effect of National Oral Health Screening Program on the Risk of Head and Neck Cancer: A Korean National Population-Based

Purpose

Poor oral health is associated with head and neck cancer (HNC). We evaluated whether a national oral health screening program (OHSP) could reduce the risk of HNC.

Materials and Methods

Data from 408,247 healthy individuals aged ≥ 40 years from the National Health Insurance System-National Health Screening program during 2003 and 2004 in Korea were analyzed. The risk of HNC was compared between subjects who underwent OHSP (HEALS-Dental+, n=165,292) and routine health check-ups only (HEALS-Dental‒, n=242,955). The impact of individual oral health-related factors on HNC risk was evaluated in HEALS-Dental+.

Results

A total of 1,650 HNC cases were diagnosed. The 10-year HNC-free rate was 99.684% with a median follow-up of 11 years. The risk of all HNC (hazard ratio [HR], 1.16; 95% confidence interval [CI], 1.03 to 1.29; p=0.011) and oropharyngeal cancer (HR, 1.48; 95% CI, 1.13 to 1.94; p=0.005) was significantly higher in HEALS-Dental‒ than in HEALS-Dental+. In HEALS-Dental+, oral cavity cancer was marginally reduced (p=0.085), and missing teeth was a significant factor for HNC (HR, 1.24; 95% CI, 1.02 to 1.50; p=0.032). Toothbrushing was a significant factor in univariate analysis (p=0.028), but not in multivariate analysis (p=0.877).

Conclusion

The National OHSP significantly reduced the long-term HNC risk, particularly the incidence of oropharyngeal cancer. Routine OHSP should be considered at the population level.

Impact of Oral Hygiene on Prognosis in Patients With Squamous Cell Carcinoma of the Lower Gingiva

Objective: We aimed to analyze the significance of oral hygiene in patients with squamous cell carcinoma of the lower gingiva.

Methods: Oral hygiene was assessed using a questionnaire by calculating the oral health (OH) score and the dental care (DC) score. The association of oral hygiene with clinical pathologic variables, disease free survival (DFS), and overall survival (OS) was analyzed.

Results: Four out of 53 non-smokers and 19 out of 90 current or former smokers had an OH score of 6 (statistically significant difference, p = 0.036). Fifteen out of 63 patients with a T3/T4 tumor and 8 out of 80 patients with a T1/T2 tumor had an OH score of 6 (statistically significant difference, p = 0.026). Similar statistically significant findings were noted with respect to the DC scores, smoking status, and tumor stage. Among patients with an OH score of 0–5, the 5-year DFS and OS rates were 55 and 50%, respectively, and among patients with an OH score >5, they were 46 and 43%, respectively (both differences statistically significant, p < 0.05). Among patients with a DC score of 0–2, the 5-year DFS and OS rates were 69 and 51%, respectively and among patients with a DC score >2, they were 50 and 47%, respectively (both differences statistically significant, p < 0.05). Cox model confirmed OH and DC scores as independent factors affecting the DFS and OS.

Conclusion: Poor oral hygiene was associated with decreased DFS and OS.

Mouthwash Use and the Risk of Oral, Pharyngeal, and Laryngeal Cancer. A Meta-Analysis

Objective: The main aim of this study was to test whether the use of mouthwash is associated with subtypes of squamous cell carcinoma of the head and neck (SCCHN) and to test the potential risk of SCCHN depending on the mouthwash use duration, frequency, or alcoholic content. Materials and methods: We performed a meta-analysis using Web of Science and Scopus databases to detect the risk change associated with mouthwash use depending on the alcohol content, duration and frequency of use, and anatomical location. We used a random-effects model with the Sidik–Jonkman estimator for effect size model measures. Results: We included 17 studies in the meta-analysis containing 17,085 cases and 20,032 controls. The risk difference for SCCHN between mouthwash users and non-users was minimal, with a value of −0.02 [−0.05, 0.01]. Alcoholic mouthwash use was associated with a minimal decrease in risk (of −0.01 [−0.07, 0.05]). Frequent usage of mouthwash was associated with a statistically significant risk increase for SCCHN but the risk increase was marginal (0.04, [0.01, 0.06]). Conclusions: Overall, our study failed to show a statistically significant correlation between mouthwash use and the risk of SCCHN. The only statistically significant correlation that we could identify was between frequent usage and SCCHN, potentially caused by prolonged contact between some constituents of mouthwash (possibly alcohol) and the oral epithelium.

Oral Health and Risk of Upper Gastrointestinal Cancers in a Large Prospective Study from a High-risk Region: Golestan Cohort Study

Tooth loss and periodontal disease have been associated with several cancers, and poor oral health may be an important risk factor for upper gastrointestinal (UGI, i.e., esophageal and gastric) cancers. We assessed the relationship between oral health and UGI cancers using a large prospective study of over 50,000 adults living in Golestan Province, Iran, a high-incidence area for these cancers. Hazard ratios (HRs) and 95% confidence intervals (CI) were estimated for the association between three different measures of oral health [frequency of tooth brushing; number of missing teeth; and the sum of decayed, missing, and filled teeth (DMFT)] and UGI cancers. During a median follow-up duration of 13 years, there were 794 incident UGI cancers (396 esophageal and 398 gastric cancers). Daily tooth brushing was associated with a decreased risk of developing both esophageal (HR = 0.670; 95% CI: 0.486-0.924) and gastric (HR = 0.741; 95% CI: 0.544-1.01) cancers (combined UGI cancer HR = 0.697; 95% CI: 0.558-0.871) compared with never brushing. Tooth loss in excess of the loess smoothed, age- and sex-specific median number of teeth lost was significantly associated with esophageal (HR = 1.64; 95% CI: 1.08-2.47) and gastric cancers (HR = 1.58; 95% CI: 1.05-2.38). There were some adverse associations between DMFT and UGI cancers but most were not statistically significant. These results suggest increased risk of developing UGI cancers among individuals with poor oral health, and those who do not perform regular oral hygiene. PREVENTION RELEVANCE: Poor oral health is associated with the risk of upper gastrointestinal cancers, and oral hygiene practices may help prevent these cancers.

Oral health and longitudinal changes in fasting glucose levels: A nationwide cohort study

We investigated the association between oral hygiene indicators of periodontitis, tooth loss, and tooth brushing on the longitudinal fasting glucose level in non-diabetic subjects. Using a nationwide health screening database in Korea, we included non-diabetic individuals who received a health screening program with oral health check in 2009–2010. We constructed a linear mixed model for the longitudinal data of fasting glucose from the baseline to 2015. During the 4.84-year of median follow-up, 91,963 individuals (mean age 56.2 at baseline) underwent 392,780 health examinations with fasting glucose level (mmol/L). The presence of periodontitis was 39.3%. In the multivariate linear mixed analysis, periodontitis was related with increased fasting glucose levels (β = 0.0084, standard error = 0.0035, p = 0.018). Similarly, tooth loss was associated with increased level of fasting glucose (β = 0.0246, standard error = 0.0038, p < 0.001). Compared with tooth brushing ≤2 times/day, tooth brushing ≥3 times/day was associated with decreased fasting glucose levels (β = -0.0207, standard error = 0.0033, p < 0.001). Our data showed that periodontitis and tooth loss were associated with increased fasting glucose levels in non-diabetic individuals. The study findings imply that frequent tooth brushing may reduce fasting glucose levels. Further research is needed to determine the effect of periodontal intervention on glycemic control.

Bifacial biological effects of ethanol: acetaldehyde production by oral Streptococcus species and the antibacterial effects of ethanol against these bacteria

Background:Many previous studies have focused on the acetaldehyde produced from ethanol by oral bacteria as a risk factor for oral cancer. Most of these studies involved low ethanol concentrations (ca. 10 mM), but oral bacteria are exposed to a wide range of ethanol concentrations (100–10,000 mM) when alcoholic beverages are consumed. In contrast, ethanol is widely used at high concentrations (> 5,000 mM) as an antiseptic/disinfectant, suggesting that ethanol has bifacial biological effects; i.e. it acts as both a metabolic substrate for bacterial acetaldehyde production and an antimicrobial agent.

Materials and methods:We examined the acetaldehyde production from ethanol by oral streptococci and the effects of ethanol exposure on the growth and viability of these bacteria at a wide range of ethanol concentrations (10–10,000 mM).

Results:Acetaldehyde production was the highest at an ethanol concentration of 2,000 mM (2.1–48-fold higher than that seen at an ethanol concentration of 10 mM). Bacterial growth was inhibited by > 1,000 mM of ethanol, and the bacteria did not seem viable in the presence of > 5,000 mM of ethanol, although they still produced acetaldehyde.

Conclusion:Ethanol has bifacial biological effects, and the concentration ranges of these effects overlap.

Smoking and Drinking Adjusted Association between Head and Neck Cancers and Oral Health Status Related to Periodontitis: a Meta-Analysis

BACKGROUND

Not so many reports about the association between head and neck cancer (HNC) and oral health status related to periodontitis (OHS-P) has been published in different countries with different methods. So, there is a need for an extensive meta-analysis with the total articles published until 2020. Hence, this study aimed to estimate the association between HNC and OHS-P through a meta-analysis.

METHODS

Based on Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines, 22 studies were selected through PubMed and Cochrane Library databases. Meta-analysis using them was performed to evaluate the association. The risk of bias assessment using the Newcastle-Ottawa Scale (NOS) was applied to evaluate the quality of non-randomized studies. Publication bias was evaluated by funnel plot and Egger's regression test.

RESULTS

Since heterogeneity was significant (I² = 88%, P < 0.001), we adopted the random effect model for 22 studies. Those with bad OHS-P, compared to those with good OHS-P, were more likely to have the risk of HNC by 2.4 times (odds ratio [OR], 2.42; 95% confidence interval [CI], 1.88-3.13) for random effect model. The association included publication bias (Egger's regression, P value < 0.001). The association among five studies (I² = 39%, P = 0.16) using alveolar bone loss (ABL) or clinical attachment level (CAL) for assessing periodontitis increased to OR of 3.85 (CI, 3.04-4.88) in the fixed effect model without publication bias (Egger's regression, P = 0.66). Moreover, the association was higher in 10 fair or good NOS studies (OR, 3.08) and in 7 Asian studies (OR, 2.68), which were from the fixed model without publication bias.

CONCLUSION

Our meta-analysis showed that bad OHS-P was associated with the risk of HNC. The association was stronger in studies using ABL or CAL for assessing periodontitis.

The Impact of Dental Care in Head and Neck Cancer Outcomes: A Systematic Review and Meta-Analysis

OBJECTIVE/HYPOTHESIS

The objective of this study was to perform a systematic review and meta-analysis to determine the impact of dental care on head and neck (H&N) cancer survival.

METHODS

A comprehensive literature search was performed using PubMed, MEDLINE, and CINAHL to find all relevant studies from the date of inception to March 2020. Systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and meta-analysis was performed using the random effects logistic regression model. Primary outcomes of interest were 5-year survival and hazard ratios comparing survival between dental care subgroups.

RESULTS

H&N cancer survival rates strongly correlate with dental care adherence. Patients with good dental care had significantly better survival than patients with poor dental care (HR = 0.67, 95% CI: 0.55-0.83), with similar improved survival among patients with moderate versus poor dental care (HR = 0.67, 95% CI: 0.57-0.80). In addition, patients with good dental care had significantly decreased mortality than those with moderate dental care (HR = 0.81, 95% CI: 0.69-0.96), indicating an exposure-response gradient.

CONCLUSIONS

For patients with H&N cancer, survival is significantly higher in those who receive recommended dental care compared with those who do not.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2021.

Independent association of marijuana use and poor oral hygiene with HPV-negative but not HPV-positive head and neck squamous cell carcinomas

BACKGROUND

Sexual behavior is associated with human papillomavirus (HPV)-positive head and neck cancer, whereas tobacco and alcohol use are associated with HPV-negative cancer. A case-control study was designed to investigate additional demographic and behavioral factors independently associated with these distinct oral cancers.

METHODS

From 2011 to 2014, 249 newly diagnosed oral cavity and oropharyngeal squamous cell carcinoma (OSCC) cases were matched (1:2) on age, gender, and self-identified race to 498 controls without a cancer history attending the outpatient otolaryngology clinic at The Ohio State University in Columbus. Cases were stratified by detection of high-risk HPV DNA and RNA in tumors. Demographic and behavioral data were collected using an audio computer-assisted self-interview, and associations with HPV-positive versus HPV-negative OSCCs were investigated by use of univariable and multivariable conditional logistic regression models.

RESULTS

After adjustment for oral sexual behavior, the odds of HPV-positive cancer decreased with the patient's years of education. Annual income, tobacco smoking, alcohol drinking, marijuana smoking, and poor oral hygiene were not associated with HPV-positive OSCC. In contrast, the odds of HPV-negative OSCC increased independently with decreased annual income, decreased with a high number of marijuana hit-years, and increased with fewer than annual dental visits after adjustment for lifetime tobacco and alcohol use. Sexual behavior and education were not associated with HPV-negative OSCC.

CONCLUSIONS

The distinct risk-factor profiles for HPV-positive and HPV-negative OSCC are confirmed and extended in this case-control study, thus supporting 2 principal etiological pathways for OSCC development.

LAY SUMMARY

Sexually acquired human papillomavirus (HPV) infection is an established cause of tonsil and base of tongue cancers. This study compared and contrasted risk factors for HPV-positive and HPV-negative oral cancers. Low number of years of education and sexual behavior are associated with HPV-positive cancer. In contrast, low annual income, infrequent dental visits, and tobacco and alcohol use are associated with HPV-negative cancers. Long-term marijuana use appears protective for HPV-negative cancer. Public health efforts to address these modifiable risk factors may prevent oral cancer.

Chromatin dysregulation associated with NSD1 mutation in head and neck squamous cell carcinoma

Chromatin dysregulation has emerged as an important mechanism of oncogenesis. To develop targeted treatments, it is important to understand the transcriptomic consequences of mutations in chromatin modifier genes. Recently, mutations in the histone methyltransferase gene nuclear receptor binding SET domain protein 1 (NSD1) have been identified in a subset of common and deadly head and neck squamous cell carcinomas (HNSCCs). Here, we use genome-wide approaches and genome editing to dissect the downstream effects of loss of NSD1 in HNSCC. We demonstrate that NSD1 mutations are responsible for loss of intergenic H3K36me2 domains, followed by loss of DNA methylation and gain of H3K27me3 in the affected genomic regions. In addition, those regions are enriched in cis-regulatory elements, and subsequent loss of H3K27ac correlates with reduced expression of their target genes. Our analysis identifies genes and pathways affected by the loss of NSD1 and paves the way to further understanding the interplay among chromatin modifications in cancer.

Farhangdoost et al. use genome editing and TCGA primary tumor data to provide a link between NSD1 loss, chromatin and regulatory landscape, gene expression, and molecular characteristics of this tumor subtype. Their study extends the understanding of tumorigenic mechanisms underlying head and neck cancers with mutations in NSD1.

Epidemiologic factors in patients with advanced head and neck cancer treated with radiation therapy

BACKGROUND

Approximately 50% of patients with head and neck cancer (HNC) initially were seen with advanced disease. We aimed to evaluate the association of epidemiologic factors with advanced HNC at diagnosis.

METHODS

The OraRad multicenter prospective cohort study enrolled HNC patients receiving curative-intent radiation therapy. Factors assessed for association with advanced HNC presentation at diagnosis included demographics, social and medical history, cancer characteristics, human papilloma virus (HPV) status, and dental disease measures.

RESULTS

We enrolled 572 participants; 77% male and mean (SD) age of 61.7 (11.2) years. Oropharyngeal squamous cell carcinomas (88% HPV-related) were seen with smaller tumors, but more frequent nodal involvement. Private medical insurance and no Medicaid were associated with smaller tumors. A higher dental disease burden was associated with larger tumors.

CONCLUSIONS

Insurance status, cancer type/location, and dental disease are associated with advanced HNC and may represent potentially modifiable factors or factors to be considered in the screening process of new lesions.

Oral health and changes in lipid profile: A nationwide cohort study

AIM

We aimed to investigate the association of periodontitis and oral hygiene indicators with changes in blood lipid parameters in a nationwide, population-based cohort in a longitudinal setting.

MATERIALS AND METHODS

We included nationwide health screening program participants who underwent oral health examination in 2009-2010 and follow-up examinations for lipid profile without exposure to lipid-lowering agents.

RESULTS

During the 5.19-year median follow-up, 65,078 individuals (mean age at baseline examination: 55.41 ± 7.30 years) underwent 286,218 health examinations. The prevalence of periodontitis was 39%. In the multivariate mixed model analysis, periodontitis and tooth loss were associated with decreased high-density lipoprotein cholesterol levels (β = -0.0066 mmol/L, standard error = 0.0026, p = .013) and increased triglyceride levels (β=0.0307, mmol/L, standard error = 0.0049, p < .001), respectively. Compared with tooth brushing ≤1 time/day, tooth brushing ≥3 times/day was associated with increased high-density lipoprotein cholesterol levels (β = 0.0176 mmol/L, standard error = 0.0052, p = .006) and decreased triglyceride levels (β = -0.0285 mmol/L, standard error = 0.0090, p = .001).

CONCLUSIONS

Periodontitis and tooth loss may be attenuating factors for blood high-density lipoprotein cholesterol and triglyceride levels, respectively. Frequent tooth brushing may improve dyslipidaemia, particularly blood high-density lipoprotein cholesterol and triglyceride levels. Oral hygiene improvement may reduce the risk of dyslipidaemia.

Body mass index and self-care behaviors related to oral health-related quality of life in patients with oral squamous cell carcinoma within three months posttreatment

PURPOSE

Oral dysfunction is a common adverse event of treatment and may affect oral health-related quality of life (OHRQoL). This study aimed to identify factors associated with OHRQoL in patients with oral squamous cell carcinoma (OSCC) within the first three months posttreatment.

METHODS

This cross-sectional study examined OSCC patients who received treatment from the outpatient radiation department of a single cancer center in northern Taiwan. Demographic and clinical characteristics were recorded, and patients were assessed using the Self-Care Behaviors Scale (SCB), Oral Health Impact Profile (OHIP), and Karnofsky Performance Status (KPS) questionnaires.

RESULTS

Among 148 OSCC patients, 11.5% reported being underweight and 70.3% reported normal weight. The most common self-care factors associated with adverse effects were decreased appetite and fatigue. Psychological disability, functional limitation, and physical pain were the most negative OHRQoL factors. Poor OHRQoL was associated with more severe adverse effects after self-care behaviors, using feeding tubes during treatment, and having BMI less than 25, which together explained 33.5% of the variance in OHRQoL.

CONCLUSIONS

The severity of adverse effects after self-care behaviors and using feeding tubes during treatment strongly influenced overall OHRQoL and seven specific dimensions of OHRQoL.

Association of Tooth Loss with New-Onset Parkinson's Disease: A Nationwide Population-Based Cohort Study

Introduction

Tooth loss is associated with poor oral hygiene. During insufficient oral sanitation, focal infection and inflammation can occur and these reactions may induce systemic inflammation. Systemic inflammatory reaction may be related to the degeneration of dopamine neurons in the substantia nigra. We hypothesized that tooth loss is related to increased risk of new-onset Parkinson's disease.

Methods

Between 2003 and 2006, we included 153,165 participants from the national health insurance system-health screening cohort in Korea. The incidence of new-onset Parkinson's disease was defined as International Classification of Diseases-10 code “G20,” accompanying the prescription records for any anti-Parkinson's disease medication.

Results

Approximately 19.9% of the included participants had periodontal disease. After a median duration of 10.4 years, 1,227 (0.8%) cases of new-onset Parkinson's disease were noted. The number of tooth loss was positively related to an increased risk of new-onset Parkinson's disease. Contrastingly, the frequency of tooth brushings and dental clinic visits for any causes as well as competent dental care were negatively related to the development of new-onset Parkinson's disease. In multivariable analysis, the number of tooth loss (≥15) was positively related to new-onset Parkinson's disease development (hazard ratio: 1.38, 95% confidence interval (1.03–1.85), p=0.029, p for trend = 0.043) after adjusting variables.

Conclusion

Our study demonstrated that the number of tooth loss was positively correlated with a higher risk of new-onset Parkinson's disease development in a longitudinal study setting. Increased number of tooth loss may be an important risk indicator of new-onset Parkinson's disease.

Awareness of Oral Cancer Among Dental Patients in Mecca, Saudi Arabia

Background:

Oral Cancer (OC) is a serious health problem affecting the oral cavity, which may lead to death. Alcohol, tobacco, and chewing betel are the main risk factors. Early diagnosis and adequate knowledge of OC may improve the survival rate.

Objective:

This study aimed to assess the knowledge about oral cancer among dental patients in Mecca.

Methods:

A cross-sectional study was conducted in the dental clinics of Mecca. Interviewer-administered questionnaires were distributed to 416 respondents aged 18 or older, who spoke Arabic or English, had no history of OC, and participated voluntarily. The questionnaire consisted of three sections. The first regarded demographical data, the second measured knowledge about OC, and the third was concerned with education regarding OC provided by health-care providers. The interviewers also educated the participants by handing brochures with information about OC.

Results:

Knowledge about OC among dental patients in Mecca was found to be significantly low. Only 102 of the 416 participants (24.5%) had any knowledge. Only 3.4% of all participants had been educated about OC by their health-care providers.

Conclusion:

The results of this study show a considerable lack of general knowledge about OC among dental patients in Mecca. Health programs should be developed to raise the community’s awareness.

Periodontal Diseases as Putative Risk Factors for Head and Neck Cancer: Systematic Review and Meta-Analysis

Whether "periodontal disease" can be considered as an independent risk factor for head and neck cancer (HNC) remains controversial. The aim of the current meta-analysis was to quantitatively assess this relationship in order to determine whether this represents a true risk factor, with implications for cancer prevention and management. PubMed, Scopus, and Embase databases were systematically searched. Selective studies were reviewed, and meta-analysis was performed to estimate the pooled odds ratio (OR) with 95% confidence intervals (CIs) on eligible studies using a random effects model. In total, 21 eligible observational studies (4 cohorts and 17 case-controls) were identified for qualitative synthesis after a review of 1051 articles. Significant heterogeneity could be identified in measures utilized for reporting of periodontal disease. Meta-analysis performed on nine studies that employed objective measures for reporting periodontal disease demonstrated a significant association between periodontal disease and HNC [OR 3.17, 95% CI, 1.78-5.64]. A diseased periodontium represents an independent risk marker, and a putative risk factor, for HNC. Prospective studies with standardized measures of periodontal disease severity and extent, integrated with microbiological and host susceptibility facets, are needed to elucidate the mechanisms of this positive association and whether treatment of the former influences the incidence and outcomes for HNC.

Better oral hygiene is associated with lower risk of stroke

BACKGROUND

Periodontal disease or poor oral hygiene may lead to local infection, inflammation, and systemic inflammatory reactions, which are important mediators of development of stroke. We aimed to investigate the association of oral hygiene with risk of stroke in a nationwide population-based cohort.

METHODS

From Korean National Health Insurance System-Health Screening Cohort, 206,602 participants without missing data regarding demographic information, medical history, or blood/urine examination results were included. The presence of periodontal disease and indicators of oral hygiene, such as number of tooth brushings, dental visit history, dental scaling, and number of teeth loss and dental caries were evaluated. Occurrence of stroke including cerebral infarction, cerebral hemorrhage, and subarachnoid hemorrhage was defined as newly registration of International Classification of Diseases-10 codes from I60 to I64 accompanying brain CT and/or MR examination at that time of diagnosis.

RESULTS

The 7337 (3.6%) cases of stroke including 5795 (79.0%) cases of cerebral infarction, 1568 (21.4%) cases of cerebral hemorrhage, and 621 (8.5%) cases of subarachnoid hemorrhage occurred during a median 10.4 years follow-up. In multivariable analysis, frequent tooth brushing (≥3 times per day) was negatively associated with risk of stroke occurrence (hazard ratio [HR]: 0.78, 95% confidence interval [CI]: 0.73-0.84). Number of dental caries (≥4) was positively related to stroke occurrence (HR: 1.28, 95% CI: 1.13-1.44).

CONCLUSIONS

Regular oral hygiene behavior was negatively, and infrequent oral hygiene care was positively associated with risk of occurrence for stroke, respectively. Brushing one's teeth three or more times daily may be associated with lower risk of stroke.

Quality of information about oral cancer in Brazilian Portuguese available on Google, Youtube, and Instagram

Background

To evaluate the quality of oral cancer information in Brazilian Portuguese on Google, YouTube, and Instagram.

Material and Methods

The first 100 links of each platform characterized the initial sample. The websites and Instagram were evaluated using the JAMA benchmarks, the Discern instrument, and the Flesch readability index (Flesch Reading Ease). The existence of Health on the Net (HON) code was also registered on websites. The usefulness of each video on YouTube was classified as not useful, slightly useful, moderately useful, or very useful.

Results

Thirty-four websites, 39 Instagram posts, and 57 videos were evaluated, of which 18 (33.3%) websites and 19 (48.7%) Instagram posts covered only 2 of the 4 JAMA benchmarks. For the Discern instrument, 20 (37%) and 18 (33.3%) websites exhibited low and moderate reliability, respectively, while 26 (66.7%) Instagram posts were of low confidence. The level of intelligibility of both websites and Instagram was difficult. Only three websites exhibited the HONcode. Forty-one (71.9%) videos on YouTube were moderately useful.

Conclusions

Information on oral cancer on the Internet in Brazilian Portuguese is of low quality. Thus, educational and governmental institutions have a responsibility to produce and indicate reliable sources of information for the population.

Key words:Access to information, internet, oral cancer.

Improved oral hygiene is associated with decreased risk of new-onset diabetes: a nationwide population-based cohort study

AIMS/HYPOTHESIS

Inflammation plays an important role in the development of diabetes, a major global health problem. Periodontal disease is also common in the general population. Because periodontal disease and poor oral hygiene can provoke transient bacteraemia and systemic inflammation, we hypothesised that periodontal disease and oral hygiene indicators would be associated with the occurrence of new-onset diabetes.

METHODS

In this study we analysed data collected between 2003 and 2006 on 188,013 subjects from the National Health Insurance System-Health Screening Cohort (NHIS-HEALS) in Korea who had no missing data for demographics, past medical history, oral hygiene indicators or laboratory findings. The presence of periodontal disease was defined on the basis of a modified version of ICD-10 codes (Korean Classification of Disease, sixth edition), if claims for treatment for acute periodontitis (K052), chronic periodontitis (K053) and periodontosis (K054) were made more than two times by a dentist, or if, according to medical records, subjects received treatment by a dentist for periodontal disease with ICD-10 codes K052, K053 or K054. Oral hygiene behaviours (number of tooth brushings, a dental visit for any reason and professional dental cleaning) were collected as self-reported data of dental health check-ups. Number of missing teeth was ascertained by dentists during oral health examination. The incidence of new-onset diabetes was defined according to ICD-10 codes E10-E14. The criterial included at least one claim per year for both visiting an outpatient clinic and admission accompanying prescription records for any glucose-lowering agent, or was based on a fasting plasma glucose ≥7 mmol/l from NHIS-HEALS.

RESULTS

Of the included subjects, 17.5% had periodontal disease. After a median follow-up of 10.0 years, diabetes developed in 31,545 (event rate: 16.1%, 95% CI 15.9%, 16.3%) subjects. In multivariable models, after adjusting for demographics, regular exercise, alcohol consumption, smoking status, vascular risk factors, history of malignancy and laboratory findings, the presence of periodontal disease (HR 1.09, 95% CI 1.07, 1.12, p < 0.001) and number of missing teeth (≥15 teeth) remained positively associated with occurrence of new-onset diabetes (HR 1.21, 95% CI 1.09, 1.33, p < 0.001, p for trend <0.001). Frequent tooth brushing (≥3 times/day) was negatively associated with occurrence of new-onset diabetes (HR 0.92, 95% CI 0.89, 0.95, p < 0.001, p for trend <0.001).

CONCLUSIONS/INTERPRETATION

Frequent tooth brushing may be an attenuating factor and the presence of periodontal disease and an increased number of missing teeth may be augmenting factors for the occurrence of new-onset diabetes. Improving oral hygiene may be associated with a decreased risk of occurrence of new-onset diabetes.

Association of oral dysbiosis with oral cancer development

Oral squamous cell carcinoma (OSCC) is the leading cause of mortality for oral cancer. Numerous risk factors mainly related to unhealthy habits and responsible for chronic inflammation and infections have been recognized as predisposing factors for oral carcinogenesis. Recently, even microbiota alterations have been associated with the development of human cancers. In particular, some specific bacterial strains have been recognized and strongly associated with oral cancer development (Capnocytophaga gingivalis, Fusobacterium spp., Streptococcus spp., Peptostreptococcus spp., Porphyromonas gingivalis and Prevotella spp.). Several hypotheses have been proposed to explain how the oral microbiota could be involved in cancer pathogenesis by mainly paying attention to chronic inflammation, microbial synthesis of cancerogenic substances, and alteration of epithelial barrier integrity. Based on knowledge of the carcinogenic effects of dysbiosis, it was recently suggested that probiotics may have anti-tumoral activity. Nevertheless, few data exist with regard to probiotic effects on oral cancer. On this basis, the association between the development of oral cancer and oral dysbiosis is discussed focusing attention on the potential benefits of probiotics administration in cancer prevention.

Lifestyle risk factor related disparities in oral cancer examination in the U.S: a population-based cross-sectional study

Background

Oral cancers account for 3% of annual U.S. cancer diagnosis, 2 in 5 of which are diagnosed late when prognosis is poor. The purpose of this study was to report the population-level prevalence of oral cancer examination among adult smokers and alcohol drinkers and assess if these modifiable lifestyle factors are associated with receiving an oral cancer examination.

Methods

Adult participants ≥30 years (n = 9374) of the 2013–2016 cycles of the National Health and Nutrition Examination Survey were included. Oral cancer examination (yes/no), smoking (never, former, current) and alcohol use (abstainers, former, current) were self-reported. Survey-logistic regression estimated odds ratios (OR) and 95% confidence intervals (CIs) of ever and past year oral cancer examination adjusted for age, gender, race/ethnicity, education, income, and time since last dental visit.

Results

One third (33%) reported ever been examined for oral cancer, 66% of whom reported an examination in the past year. Adjusted OR (95% CI) of past year examination comparing current and former smokers to non-smokers were 0.51 (0.29, 0.88) and 0.74 (0.53, 1.04) respectively. Similarly, current and former alcohol drinkers relative to abstainers were less likely to report a past year oral cancer examination, OR (95% CI) = 0.84 (0.53, 1.30) and 0.50 (0.30, 0.83) respectively.

Conclusion

This study showed that smokers and alcohol users were less likely than abstainers to self-report a past year oral cancer examination. Access to affordable and targeted oral cancer examination within the dental care setting might ensure that these high-risk individuals get timely examinations and earlier diagnosis that might improve prognosis and survival.

Characteristics and prognosis of primary treatment-naïve oral cavity squamous cell carcinoma in Norway, a descriptive retrospective study

Objectives

Incidence of oral cavity squamous cell carcinomas is rising worldwide, and population characterization is important to follow for future trends. The aim of this retrospective study was to present a large cohort of primary oral cavity squamous cell carcinoma from all four health regions of Norway, with descriptive clinicopathological characteristics and five-year survival outcomes.

Materials and methods

Patients diagnosed with primary treatment-naïve oral cavity squamous cell carcinomas at all four university hospitals in Norway between 2005–2009 were retrospectively included in this study. Clinicopathological data from the electronic health records were compared to survival data.

Results

A total of 535 patients with primary treatment-naïve oral cavity squamous cell carcinomas were identified. The median survival follow-up time was 48 months (range 0–125 months) after treatment. The median five-year overall survival was found to be 47%. Median five-year disease-specific survival was 52%, ranging from 80% for stage I to 33% for stage IV patients. For patients given treatment with curative intent, the overall survival was found to be 56% and disease-specific survival 62%. Median age at diagnosis was 67 years (range 24–101 years), 64 years for men and 72 years for women. The male: female ratio was 1.2. No gender difference was found in neither tumor status (p = 0.180) nor node status (p = 0.266), but both factors influenced significantly on survival (p<0.001 for both).

Conclusions

We present a large cohort of primary treatment-naïve oral cavity squamous cell carcinomas in Norway. Five-year disease-specific survival was 52%, and patients eligible for curative treatment had a five-year disease-specific survival up to 62%.

Awareness on oral cancer among patients attending dental school clinics in Brazil

Background

Oral cancer is considered a public health problem worldwide. Dental schools may play an important role in educating patients about oral cancer. This study aimed at evaluating the knowledge of patients attending clinics at two dental schools in Brazil.

Material and Methods

From March 2017 to April 2017, 251 patients who were attending clinics at two dental schools in Recife, Brazil, were included in the study. Patients were contacted in the waiting rooms of the clinic. Each participant completed a self-administered questionnaire, which consists of 21 questions, including socio-demographic and specific information on the disease. Data were analyzed using descriptive statistics, and a chi-square test (with a 5% significance level) was used to assess the correlation between the variables, education and family income and other variables.

Results

Most participants were women (64.9%) with a mean age of 42.72 years. Most participants were knowledgeable about oral cancer and identified tobacco use (48.6%), alcohol consumption (25.1%), and solar radiation (12%) as the primary risk factors for the disease. Only 36.7% of the participants reported having received counselling on oral cancer, of which 18.3% received the information from a dentist. All patients with an income higher than six minimum wages were aware about oral cancer (p = 0.001).

Conclusions

These findings emphasize the importance of educational programs in dental schools as well providing integrated services for patients seeking care at school clinics, including population’s awareness on oral cancer.

Key words:Dental school, knowledge, oral cancer, oral health education, patient education.

Improved oral hygiene care is associated with decreased risk of occurrence for atrial fibrillation and heart failure: A nationwide population-based cohort study

AIMS

Poor oral hygiene can provoke transient bacteremia and systemic inflammation, a mediator of atrial fibrillation and heart failure. This study aims to investigate association of oral hygiene indicators with atrial fibrillation and heart failure risk in Korea.

METHODS

We included 161,286 subjects from the National Health Insurance System-Health Screening Cohort who had no missing data for demographics, past history, or laboratory findings. They had no history of atrial fibrillation, heart failure, or cardiac valvular diseases. For oral hygiene indicators, presence of periodontal disease, number of tooth brushings, any reasons of dental visit, professional dental cleaning, and number of missing teeth were investigated.

RESULTS

During median follow-up of 10.5 years, 4911 (3.0%) cases of atrial fibrillation and 7971 (4.9%) cases of heart failure occurred. In multivariate analysis after adjusting age, sex, socioeconomic status, regular exercise, alcohol consumption, body mass index, hypertension, diabetes, dyslipidemia, current smoking, renal disease, history of cancer, systolic blood pressure, blood and urine laboratory findings, frequent tooth brushing (≥3 times/day) was significantly associated with attenuated risk of atrial fibrillation (hazard ratio: 0.90, 95% confidence interval (0.83-0.98)) and heart failure (0.88, (0.82-0.94)). Professional dental cleaning was negatively (0.93, (0.88-0.99)), while number of missing teeth ≥22 was positively (1.32, (1.11-1.56)) associated with risk of heart failure.

CONCLUSION

Improved oral hygiene care was associated with decreased risk of atrial fibrillation and heart failure. Healthier oral hygiene by frequent tooth brushing and professional dental cleaning may reduce risk of atrial fibrillation and heart failure.

Dental disease before radiotherapy in patients with head and neck cancer: Clinical Registry of Dental Outcomes in Head and Neck Cancer Patients

BACKGROUND

No evidence-based guidelines exist for preventive dental care before radiation therapy (RT) in patients with head and neck cancer (HNC). An ongoing multicenter, prospective cohort study, Clinical Registry of Dental Outcomes in Head and Neck Cancer Patients (OraRad), is addressing this knowledge gap. The authors evaluated the level of dental disease before RT in the OraRad cohort, factors associated with dental disease, and dental treatment recommendations made before RT.

METHODS

As part of OraRad, the authors assessed caries, periodontal disease, dental recommendations, and dental interventions performed before RT.

RESULTS

Baseline measures were reported for 356 participants (77% men) with mean (standard deviation) age of 59.9 (11.0) years. Measures included mean number of teeth (22.9), participants with at least 1 tooth with caries (37.2%), and participants with at least 1 tooth with probing depth 5 millimeters or greater (47.4%). Factors associated with less extensive dental disease before RT included having at least a high school diploma, having dental insurance, history of routine dental care, and a smaller tumor size (T1 or T2). Based on the dental examination before RT, 163 (49.5%) participants had dental treatment recommended before RT, with extractions recommended most frequently.

CONCLUSION

Many patients with HCN require dental treatment before RT; more than one-third require extractions.

PRACTICAL IMPLICATIONS

Most patients have some level of dental disease at the start of RT, indicating the importance of dental evaluation before RT. By observing dental outcomes after RT, OraRad has the potential to determine the best dental treatment recommendations for patients with HCN.

Mouth Cancer Awareness in General Population: Results from Grampian Region of Scotland, United Kingdom

Objectives

The purpose of this project was to determine the level of mouth cancer awareness and to investigate the associated factors in a United Kingdom (UK) general population sample.

Material and Methods

Adult Dental Health Survey (2010) was conducted in a sample of 3,353 adult residents in the Grampian region of the UK (adjusted participation rate 58%). Participants completed a questionnaire consisting of questions on oral health, health behaviour, quality of life and cancer awareness.

Results

Overall, 81% of participants were aware of mouth cancer. This was associated with younger age, higher levels of education and better general health. Current smokers and alcohol drinkers were more aware of mouth cancer. When asked about risk factors for mouth cancer, the following were identified by the respondents: smoking (84%), poor oral hygiene (60%), drinking alcohol heavily (59%), poor diet (37%), stress (15%), being overweight (6%), drinking hot liquids (5%), eating spicy food (3%), using mouthwash (2%) and kissing someone (1%). Smokers were more likely to identify smoking as a risk factor for mouth cancer. Similarly, those who consumed alcohol almost daily were more likely to identify heavy alcohol drinking as a risk factor.

Conclusions

Awareness of mouth cancer is high in respondents from the general population, and participants were able to identify the most important risk factors. Knowledge of tobacco and alcohol as risk factors was highest amongst those exposed to them. The study proposed that the prevention strategies should focus not only on increasing knowledge, but also on changing health behaviour.

Metabolic property of acetaldehyde production from ethanol and glucose by oral Streptococcus and Neisseria

Acetaldehyde is known to be carcinogenic and produced by oral bacteria. Thus, bacterial acetaldehyde production might contribute to oral cancer. Therefore, we examined bacterial acetaldehyde production from ethanol and glucose under various conditions mimicking the oral cavity and clarified the metabolic pathways responsible for bacterial acetaldehyde production. Streptococcus mitis, S. salivarius, S. mutans, Neisseria mucosa and N. sicca were used. The bacterial metabolism was conducted at pH 5.0–8.0 under aerobic and anaerobic conditions. The production of acetaldehyde and organic acids was measured with gas chromatography and HPLC, respectively. Bacterial enzymes were also assessed. All of the bacteria except for S. mutans exhibited their greatest acetaldehyde production from ethanol at neutral to alkaline pH under aerobic conditions. S. mutans demonstrated the greatest acetaldehyde from glucose under anaerobic conditions, although the level was much lower than that from ethanol. Alcohol dehydrogenase and NADH oxidase were detected in all of the bacteria. This study revealed that oral indigenous bacteria, Streptococcus and Neisseria can produce acetaldehyde, and that such acetaldehyde production is affected by environmental conditions. It was suggested that alcohol dehydrogenase and NADH oxidase are involved in ethanol-derived acetaldehyde production and that the branched-pathway from pyruvate is involved in glucose-derived acetaldehyde production.

Knowledge and Attitudes of Primary Health Care Dentists Regarding Oral Cancer in Brazil

Objective

The aim of this study was to evaluate the knowledge and attitudes of dentists working in Primary Health Care Units from a Brazilian city, regarding oral cancer.

Materials and methods

A prospective, cross-sectional, epidemiologic survey was performed. Seventy-one dentists from Primary Health Care Units were contacted at their workplace, and participated of the study. Data were collected through a self-administered questionnaire of 31 multiple-choice questions addressing the main clinical features and risk factors for oral cancer. The questionnaire was divided into two sections: questions related to general data and self-perception of the participants regarding personal knowledge of oral cancer, and objective questions related to general information on oral cancer (clinical features, characteristics, traits, and risk factors). The data were tabulated and analyzed by descriptive statistics.

Results

Participants were mostly females (81.5%), less than 40 years of age (57.7%), who underwent training 10–20 years ago (47.9%). Most respondents (66.2%) considered their level of knowledge about oral cancer to be satisfactory. However, only 26.8% of tem felt that they were able to carry out diagnostic procedures for oral cancer. Most of them (95.8%) were interested in participating in training courses on Oral Diagnostics; 56.3% of them reported not having received any training or guidance on how to conduct an examination to detect oral cancer during undergraduate training.

Conclusions

These findings are consistent with previous reports and point to the need for new public policies to enable early diagnosis of oral cancer and a review of training in Oral Diagnostics in dental schools.