Enhancing surgical outcomes of posterior iliac bone harvesting through a pivotal modification.

Traditionally, patients are positioned in the prone position to access the donor site during the posterior iliac bone graft harvesting procedure. However, this well-established method is associated with complications such as pressure injuries, displacement of the endotracheal tube and intravenous catheter, and blindness. Moreover, the process of turning patients 180° between the supine and prone positions is both laborious and time consuming. However, no updates have been made in the approaches published in the literature to counteract these problems. Therefore, to overcome these challenges and improve patient outcomes, we proposed a pivotal modification: change prone position to the lateral decubitus position. This approach allowed us to effectively avoid the aforementioned complications. In addition, this modification offered significant advantages, including ease of implementation and timesaving benefits. The article presented results of the modification and a comprehensive evaluation of clinical and anesthetic considerations comparing the two methods.

Validation of Alcohol Flushing Questionnaire to Identify ALDH2 Status in a Case-Control Study of Head and Neck Cancer.

BACKGROUND: Carriers of the ALDH2*2 allele have impaired alcohol metabolism and are more susceptible to the development of alcohol-related cancers, including head and neck cancer (HNC). Screening for ALDH2*2 allele may identify high-risk individuals for alcohol health education. Although genotyping of ALDH2 is the most accurate way to identify ALDH2 deficiency, it may not be practical due to the cost and requirement for genotyping service. METHODS: This study evaluated the accuracy of the alcohol flushing questionnaire to identify ALDH2 deficiency in a case-control study of HNC conducted in Taiwan using data collected from 904 patients with HNC and 1,078 controls. RESULTS: Overall, alcohol flushing questionnaire had a high sensitivity (89%) of identifying ALDH2*2 carriers among the control subjects and a good sensitivity (79%) among the patients with HNC. The sensitivity of the alcohol flushing questionnaire in identifying ALDH2*2 carriers was affected by alcohol use, with a lower sensitivity among individuals who consumed alcohol, particularly among current regular (drinking alcohol once per week or more) alcohol drinkers. CONCLUSIONS: The current validation study showed that the alcohol flushing questionnaire may be a reasonable method to identify ALDH2-deficient individuals. However, current regular users of alcohol who reported no alcohol flushing may need to undergo genotyping of ALDH2 for a more accurate assessment of the ALDH2 status.

Oral hygiene and the overall survival of head and neck cancer patients.

Poor oral hygiene is an established risk factor of head and neck cancer (HNC); however, its role in the survival of HNC patients is unclear. This study evaluated the association between oral hygiene habits, including regular dental visits, frequency of tooth brushing, and use of dental floss, and the overall survival (OS) of HNC patients using interview data collected from 740 HNC patients. In addition, the interactions between oral hygiene and the polymorphisms of TLR2 and TLR4 on the OS of HNC patients were assessed. The analysis indicated that poor oral hygiene was significantly associated with poorer OS of HNC patients (hazard ratio (HR) = 1.38, 95% confidence interval (CI): 1.03-1.86). This association was modified by a single nucleotide polymorphism, rs11536889, of TLR4. A significant association between poor oral hygiene and worse survival of HNC was observed among those with the CG or CC genotype (HR = 2.32, 95% CI: 1.41-3.82) but not among those with the GG genotype (HR = 0.95, 95% CI: 0.65-1.40). Our results suggested that poor oral hygiene is not only a risk factor but may also be a prognostic factor of HNC.

Unusual Supernumerary Teeth and Treatment Outcomes Analyzed for Developing Improved Diagnosis and Management Plans.

PURPOSE: Supernumerary teeth (SNTs) are teeth or tooth-like structures that have erupted or might erupt in addition to the 20 primary or 32 permanent teeth. The simultaneous presentation of multiple SNTs, syndrome-related multiple SNTs, SNTs inside the maxillary sinus and treatment outcomes were analyzed to develop improved diagnosis and management plans. PATIENTS AND METHODS: This retrospective study reviewed the medical records of National Cheng Kung University Hospital patients who had undergone surgical intervention with general anesthesia between February 2014 and September 2018; analyzed panoramic radiographs and cone beam computed tomography scans of their multiple SNTs; and used descriptive statistics to discuss treatments and relative complications, especially of unusual SNTs. RESULTS: The records of 165 patients (127 male and 38 female patients; mean age, 12.4 years) with 241 SNTs (120 patients had 1 SNT, 35 had 2 SNTs, 3 had 3 SNTs, 2 had 4 SNTs, 2 had 5 SNTs, 2 had 6 SNTs, and 1 had 12 SNTs) were reviewed. There were 185 SNTs in the maxilla and 56 in the mandible; 153 were mesiodens and 115 were inverted; 142 were asymptomatic and 137 were conical; and 228 were fully impacted and 210 were partial roots. Two patients had SNTs inside the maxillary sinus, and one had 5 SNTs and Marfan syndrome. Two patients had postoperative lip or chin paresthesia, and two had postoperative sinusitis. CONCLUSIONS: Patient demographic variables provided useful epidemiologic information. We recommend panoramic radiographs or cone beam computed tomography for managing patients with possible multiple SNTs and for extracting SNTs.

Dental cement's biological and mechanical properties improved by ZnO nanospheres.

Metal oxide nanoparticles are a new class of important materials used in a wide variety of biomedical applications. Bulk zinc oxide (ZnO) particles have been used for temporal or permanent luting cement because of their excellent mechanical strength and biocompatibility. ZnO nanoparticles have distinct optical and antibacterial properties and a high surface-to-volume ratio. We investigated the mechanical and antibacterial properties of luting cement with different ratios of ZnO nanospheres. We showed that luting cement with 5% and 10% ZnO nanospheres was less soluble in low-pH (pH 3) artificial saliva. Antibacterial activity was 40% higher for Streptococcus mutans and 90% higher for Porphyromonas gingivalis when >10% (w/v) of the bulk particles were replaced with ZnO nanospheres in ZnO polycarboxylate cement. ZnO nanospheres were also biocompatible with mammalian cells. Additionally, the compressive strength was 1.2 times greater and the diametral tensile strength was 1.5 times greater for cements with 10% ZnO nanospheres than for conventional ZnO polycarboxylate cement. We propose a new method for improving dental luting cement by integrating it with ZnO nanospheres. This method simultaneously adds their greater antibacterial, mechanical, and acid resistance properties and retains an outstanding degree of biocompatibility.

The Influence of Prediagnosis Alcohol Consumption and the Polymorphisms of Ethanol-Metabolizing Genes on the Survival of Head and Neck Cancer Patients.

BACKGROUND: Although alcohol drinking is an established risk factor of head and neck cancer (HNC), less is known about its role in the prognosis of HNC. The current study investigated the association between pretreatment alcohol consumption and the overall survival (OS) of HNC patients. METHODS: Cox proportional hazards models were performed to evaluate the association between prediagnosis alcohol drinking and the OS of HNC patients. In addition, the influence of the polymorphisms of two ethanol-metabolizing genes, ADH1B and ALDH2, on this relationship was also evaluated. RESULTS: The results showed a significant positive dose-response relationship between prediagnosis alcohol use and worse OS of HNC patients. This association was more significant for oropharyngeal cancer, hypopharyngeal cancer, and laryngeal cancer than for oral cancer. The association between alcohol use and the poorer OS of HNC patients was mainly through its association with a higher stage of HNC at diagnosis. The worst OS associated with alcohol use was observed among HNC patients with the fast ADH1B and the slow/nonfunctional ALDH2 genotype combination. CONCLUSIONS: Our analysis showed a significant positive dose-response relationship between prediagnosis alcohol use and a worse OS of HNC. This association was mainly due to the higher stage of HNC among alcohol drinkers. In addition, the polymorphisms of the ethanol-metabolizing genes, ADH1B and ALDH2, modified the relationship between prediagnosis alcohol use and the OS of HNC patients. IMPACT: Prediagnosis alcohol use may be a prognostic indicator of HNC.

Two-channel autofluorescence analysis for oral cancer.

We created a two-channel autofluorescence test to detect oral cancer. The wavelengths 375 and 460 nm, with filters of 479 and 525 nm, were designed to excite and detect reduced-form nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) autofluorescence. Patients with oral cancer or with precancerous lesions, and a control group with healthy oral mucosae, were enrolled. The lesion in the autofluorescent image was the region of interest. The average intensity and heterogeneity of the NADH and FAD were calculated. The redox ratio [(NADH)/(NADH + FAD)] was also computed. A quadratic discriminant analysis (QDA) was used to compute boundaries based on sensitivity and specificity. We analyzed 49 oral cancer lesions, 34 precancerous lesions, and 77 healthy oral mucosae. A boundary (sensitivity: 0.974 and specificity: 0.898) between the oral cancer lesions and healthy oral mucosae was validated. Oral cancer and precancerous lesions were also differentiated from healthy oral mucosae (sensitivity: 0.919 and specificity: 0.755). The two-channel autofluorescence detection device and analyses of the intensity and heterogeneity of NADH, and of FAD, and the redox ratio combined with a QDA classifier can differentiate oral cancer and precancerous lesions from healthy oral mucosae.

Growth-regulated oncogene-α from oral submucous fibrosis fibroblasts promotes malignant transformation of oral precancerous cells.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a common human malignancy and is usually preceded by the oral precancerous lesions. Oral submucous fibrosis (OSF) is one of the oral precancerous lesions with high incidence of malignant transformation. In addition to cancer cells, cancer-associated fibroblasts in the tumor microenvironment are correlated with cancer progression, but the role of fibroblasts from OSF in tumorigenesis and progression is still unknown. Growth-regulated oncogene-α (GRO-α), a member of CXC chemokine family, is related to tumorigenesis in several cancers. In this study, we would like to explore the role of GRO-α from OSF-associated fibroblasts in oral cancer progression. METHODS: We isolated primary culture fibroblasts of normal, precancerous, and tumor tissues from patients with OSCC accompanied with OSF. A cytokine array was used to screen cytokine secretions in the conditioned media of the fibroblasts. A wound healing migration assay, WST-1 cell proliferation assay, rhodamine-phalloidin staining, and soft agar colony formation assay were used to investigate the effects of GRO-α on a dysplastic oral keratinocyte cell line (DOK) cell migration, growth, and anchorage-independent growth. RESULTS: GRO-α was identified to be increased in conditioned media of OSF-associated fibroblasts. GRO-α promotes DOK cells proliferation, migration, and anchorage-independent growth through enhancing the EGFR/ERK signaling pathway, F-actin rearrangement, and stemness properties, respectively. Moreover, GRO-α neutralizing antibodies downregulated the conditioned medium-induced cell proliferation and migration of DOK. CONCLUSION: GRO-α from OSF-associated fibroblasts paracrinally promotes oral malignant transformation and significantly contributes to OSCC development.

The interplay between oral microbiome, lifestyle factors and genetic polymorphisms in the risk of oral squamous cell carcinoma.

Poor oral hygiene may lead to overgrowth of pathogenic oral bacteria, which may induce chronic inflammation to promote the oncogenesis of oral squamous cell carcinoma (OSCC). This study investigated the association between oral bacterial profile and OSCC risk in a case-control study of 138 OSCC cases and 151 controls (88 cases and 90 controls for the discovery group and 50 cases and 61 controls for the validation group). Oral bacterial profiles were characterized by targeted sequencing of the 16S rRNA gene. Three species of periodontopathogenic bacteria, Prevotella tannerae, Fusobacterium nucleatum, and Prevotella intermedia, were associated with an increased OSCC risk. This association was modified by the genetic polymorphisms of TLR2 and TLR4. Use of alcohol, betel quids and cigarettes and poor oral hygiene were associated with a higher percentage of oral periodontopathogenic bacteria. The association between alcohol and periodontopathogenic bacteria was modified by the genetic polymorphism of ALDH2, with a stronger positive association observed among the ALDH2-deficient individuals. The percentage of periodontopathogenic bacteria was positively correlated with the level of salivary IL1ß, an inflammatory cytokine. Overall, our results showed a positive association between periodontopathogenic bacteria and OSCC risk and this relationship may be influenced by lifestyle and genetic factors. Our results provided further biological support for the established association between poor oral hygiene and OSCC risk. This suggested that improving oral hygiene may reduce OSCC risk and should be part of a public health campaign to prevent the occurrence of OSCC.

Plane-to-plane analysis of mandibular misalignment in patients with facial asymmetry.

INTRODUCTION: Little is known regarding how the mandible rotates in facial asymmetry. The purpose of this study was to study mandibular misalignment with a new plane-to-plane analysis method in patients with facial asymmetry. METHODS: Optimal symmetry planes (OSPs) were generated by computing the greatest count of paired voxels on opposing sides of the computerized tomography image of the structure. The mandibular OSP was measured against the midfacial OSP for its alignment. The deviation angle formed by the 2 OSPs was broken down into a y-axis component (frontal deviation angle) and a z-axis component (horizontal deviation angle). Fifty-nine patients who sought correction for facial asymmetry were included for study. RESULTS: The new analysis method was feasible. Fifty patients (83%) had significant mandibular misalignment (deviation, ≥4° or 4 mm). The locations of the rotational axes exhibited significant variations that could explain the varied features of the asymmetry. The frontal deviation angle (mean, 3.80° ± 3.89°) was significantly larger than the horizontal deviation angle (mean, 2.77° ± 1.71°). There was no significant correlation between the horizontal deviation angle and the anterior deviation distance or the posterior deviation distance. CONCLUSIONS: Proper mandibular realignment was suggested to be the primary aim in surgical correction of most jawbone asymmetries. Because of the greatly varied rotational axes and the obscure z-axis rotation, realignment could be difficult with the traditional approach. The OSP-based analysis is advocated to guide planning.

Investigating the association between diet and risk of head and neck cancer in Taiwan.

Most studies reporting an inverse association between the consumption of vegetables and fruits and head and neck cancer (HNC) risk were conducted in Western populations and only a few included East Asians. The current case-control study investigated the association between diet and HNC risk using data of 838 HNC cases and 998 controls from a case-control study of HNC conducted in Taiwan. Each participant was asked about their consumption of fresh vegetables, pickled vegetables, fresh fruits, citrus fruits, meat, processed meat, fish, egg, and dairy products. Unconditional logistic regression was performed to estimate the odds ratio (OR) and 95% confidence interval (CI) of HNC risk associated with each food category, adjusted for sex, age, education, and use of alcohol, betel quid and cigarette. An inverse association was observed between HNC risk and daily intake of fresh vegetables (OR = 0.44, 95% CI: 0.20-0.95, p-trend = 0.002) or fruits (OR = 0.55, 95% CI: 0.43-0.72, p-trend = 0.00001). Individuals who did not consume fresh fruits and vegetables daily had more than double the risk of HNC compared to those with daily intake of vegetables and fruits (OR= 2.24, 95% CI: 1.54-3.25). The results of the current study supported an inverse association between the consumption of fresh vegetables and fruits and HNC risk. In addition to cessation of cigarette smoking and betel quid chewing and reduction of alcohol drinking, a public health campaign for preventing the occurrence of HNC should promote a healthy diet that contains plenty of fresh vegetables and fruits.

Investigating the Association between Alcohol and Risk of Head and Neck Cancer in Taiwan.

Although alcohol is an established risk factor of head and neck cancer (HNC), insufficiencies exist in the literature in several aspects. We analyzed detailed alcohol consumption data (amount and type of alcoholic beverage) of 811 HNC patients and 940 controls to evaluate the association between alcohol and HNC by HNC sites and by genotypes of ADH1B and ALDH2. Alcohol was associated with an increased HNC risk in a dose-response relationship, with the highest risk observed for hypopharyngeal cancer, followed by oropharyngeal and laryngeal cancers. Liquor showed a stronger positive association with HNC than beer and wine. The highest HNC risk occurred in individuals with the slow ADH1B and slow/non-functional ALDH2 genotype combination. In our study population, 21.8% of HNCs, 55.7% of oropharyngeal cancers, and 89.1% of hypopharyngeal cancers could be attributed to alcohol. Alcohol accounted for 47.3% of HNCs among individuals with the slow ADH1B and slow/non-functional ALDH2 genotype combination. The HNC risk associated with alcohol became comparable to that of never/occasional drinkers after ten or more years of cessation from regular alcohol drinking. In conclusion, alcohol use is associated with an increased HNC risk, particularly for individuals with slow ethanol metabolism. HNC incidence may be reduced by alcohol cessation.

Novel quantitative analysis of autofluorescence images for oral cancer screening.

OBJECTIVES: VELscope® was developed to inspect oral mucosa autofluorescence. However, its accuracy is heavily dependent on the examining physician's experience. This study was aimed toward the development of a novel quantitative analysis of autofluorescence images for oral cancer screening. MATERIALS AND METHODS: Patients with either oral cancer or precancerous lesions and a control group with normal oral mucosa were enrolled in this study. White light images and VELscope® autofluorescence images of the lesions were taken with a digital camera. The lesion in the image was chosen as the region of interest (ROI). The average intensity and heterogeneity of the ROI were calculated. A quadratic discriminant analysis (QDA) was utilized to compute boundaries based on sensitivity and specificity. RESULTS: 47 oral cancer lesions, 54 precancerous lesions, and 39 normal oral mucosae controls were analyzed. A boundary of specificity of 0.923 and a sensitivity of 0.979 between the oral cancer lesions and normal oral mucosae were validated. The oral cancer and precancerous lesions could also be differentiated from normal oral mucosae with a specificity of 0.923 and a sensitivity of 0.970. CONCLUSION: The novel quantitative analysis of the intensity and heterogeneity of VELscope® autofluorescence images used in this study in combination with a QDA classifier can be used to differentiate oral cancer and precancerous lesions from normal oral mucosae.

Regular recreational physical activity and risk of head and neck cancer.

BACKGROUND: Although substantial evidence supports a 20-30% risk reduction of colon cancer, breast cancer, and endometrial cancer by physical activity (PA), the evidence for head and neck cancer (HNC) is limited. Three published studies on the association between PA and HNC have generated inconsistent results. The current study examined the association between recreational PA (RPA) and HNC risk with a more detailed assessment on the intensity, frequency, duration, and total years of RPA. METHODS: Data on RPA were collected from 623 HNC cases and 731 controls by in-person interview using a standardized questionnaire. The association between RPA and HNC risk was assessed using unconditional logistic regression, adjusted for sex, age, educational level, use of alcohol, betel quid, and cigarette, and consumption of vegetables and fruits. RESULTS: A significant inverse association between RPA and HNC risk was observed in a logistic regression model that adjusted for sex, age, and education (odds ratio (OR) = 0.65, 95% confidence interval (CI): 0.51-0.82). However, after further adjustment for the use of alcohol, betel quid, and cigarette, and consumption of vegetables and fruits, RPA was no longer associated with HNC risk (OR =0.97, 95% CI: 0.73-1.28). No significant inverse association between RPA and HNC risk was observed in the analysis stratified by HNC sites or by the use of alcohol, betel quid, or cigarette. CONCLUSION: Results from our study did not support an inverse association between RPA and HNC risk. The major focus of HNC prevention should be on cessation of cigarette smoking and betel chewing, reduction of alcohol drinking, and promotion of healthy diet that contains plenty of fruits and vegetables.

A Comprehensive Analysis on the Association between Tobacco-Free Betel Quid and Risk of Head and Neck Cancer in Taiwanese Men.

OBJECTIVES: Although betel quid (BQ) is an established risk factor of head and neck cancer (HNC), insufficiencies exist in the literature regarding the dose-response, BQ types, HNC sites, and BQ cessation. The current study was conducted to fill these insufficiencies. MATERIALS AND METHODS: A hospital-based case-control study was conducted to evaluate the association between BQ and HNC. In-person interview was conducted to collect data on BQ chewing. The current analysis included 487 men newly diagnosed with HNC and 617 male controls who were frequency-matched to the cases by age. The association between BQ and HNC was assessed using multivariable unconditional logistic regression. RESULTS: Ever BQ chewing was associated with an increased HNC risk regardless of the BQ types. A non-linear positive association between BQ and HNC was observed, with a steep rise in HNC risk for the first 5 pack-years or 200,000 minutes of BQ consumption. Every year of BQ cessation was associated with a 2.9% reduction in HNC risk; however, the risk did not reduce to the level of non-BQ chewers even after 20 years of BQ cessation. Eliminating BQ chewing may prevent 51.6% of HNCs, 62.6% of oral cancers, and 41.3% of pharyngeal cancers in Taiwan. CONCLUSION: Our results supported the positive association between BQ and HNC. BQ cessation is effective in reducing HNC risk and should be encouraged. Because BQ cessation may not reduce the HNC risk to the level of non-BQ chewers, it is important to prevent the initiation of BQ chewing.

Allergy symptoms, serum total immunoglobulin E, and risk of head and neck cancer.

PURPOSE: Allergy symptoms have been associated with a reduced head and neck cancer (HNC) risk, while elevated blood immunoglobulin E (IgE) levels have been associated with an increased HNC risk. According to the "prophylaxis hypothesis," allergic reaction is the body's way of expelling carcinogens. IgE level may be increased by exposure to environmental carcinogens, including alcohol and cigarette smoke. We hypothesized that individuals with elevated serum IgE without allergy symptoms (i.e., asymptomatic atopic) would have the highest HNC risk. METHODS: A case-control study of HNC (576 cases and 740 controls) was conducted to evaluate the association between allergy symptoms or serum total IgE and HNC risk and the effect modification of allergy symptoms on the association between serum total IgE and HNC risk. RESULTS: Elevated serum total IgE was associated with a significantly increased HNC risk [odds ratio (OR) 1.71, 95 % confidence interval (CI) 1.21-2.42]. Having allergy symptoms was associated with a significantly reduced HNC risk (OR 0.56, 95 % CI 0.43-0.73). Compared to subjects with normal serum total IgE and no allergy symptoms, asymptomatic atopic individuals had a significantly increased HNC risk (OR 2.12, 95 % CI 1.33-3.35). CONCLUSIONS: Our results provided further evidence to support the "prophylaxis hypothesis." Further investigations regarding the immune profiles of asymptomatic atopic individuals may provide additional clues for the biological mechanisms underlying the association between allergy symptoms, IgE, and HNC risk.

Alcohol Drinking Obliterates the Inverse Association Between Serum Retinol and Risk of Head and Neck Cancer.

This analysis evaluated the association between serum retinol levels and risk of head and neck cancer (HNC) and whether the association is modulated by the use of alcohol, betel quid, or cigarette. In addition, we also examined the association between HNC risk and 2 single nucleotide polymorphisms, TTR rs1667255 and RBP4 rs10882272, that have been associated with serum retinol levels. Unconditional logistic regression was performed to evaluate the association between serum retinol levels and HNC risk among 160 HNC cases and 198 controls. The associations between TTR rs1667255 and RBP4 rs10882272 and serum retinol levels or HNC risk were evaluated by linear regression and unconditional logistic regression, respectively, for 418 HNC cases and 497 controls. The results showed that HNC cases had a lower mean serum retinol level compared with controls (845.3 µg/L vs 914.8 µg/L, P = 0.03). An inverse association between serum retinol levels and HNC risk occurred among never/occasional alcohol drinkers but not among regular drinkers. TTR rs1667255 was associated with serum retinol levels; however, neither TTR rs1667255 nor RBP4 rs10882272 was associated with HNC risk. In summary, this study showed an inverse association between serum retinol levels and HNC risk, specifically among never/occasional alcohol drinkers. More studies are needed to establish the underlying biologic mechanisms for the inverse association between serum retinol levels and HNC risk and the modulation of this relationship by alcohol drinking.

Downregulated miR329 and miR410 promote the proliferation and invasion of oral squamous cell carcinoma by targeting Wnt-7b.

microRNA (miRNA) dysregulation contributes widely to human cancer but has not been fully assessed in oral cancers. In this study, we conducted a global microarray analysis of miRNA expression in 40 pairs of betel quid-associated oral squamous cell carcinoma (OSCC) specimens and their matched nontumorous epithelial counterparts. Eighty-four miRNAs were differentially expressed in the OSCC specimens compared with the matched tissue. Among these downregulated miRNAs, 19 miRNAs were found and mapped to the chromosome 14q32.2 miRNA cluster region, which resides within a parentally imprinted region designated as Dlk-Dio3 and known to be important in development and growth. Bioinformatic analysis predicted two miRNAs from the cluster region, miR329 and miR410, which could potentially target Wnt-7b, an activator of the Wnt-ß-catenin pathway, thereby attenuating the Wnt-ß-catenin signaling pathway in OSCC. Stable ectopic expression of Wnt-7b in OSCC cells overexpressing miR329 or miR410 restored proliferation and invasion capabilities abolished by these miRNA. Combining a demethylation agent and a histone deacetylase inhibitor was sufficient to reexpress miR329, miR410, and Meg3, consistent with epigenetic regulation of these miRNA in human OSCC. Specifically, arecoline, a major betel nut alkaloid, reduced miR329, miR410, and Meg3 gene expression. Overall, our results provide novel molecular insights into how betel quid contributes to oral carcinogenesis through epigenetic silencing of tumor-suppressor miRNA that targets Wnt-ß-catenin signaling.

Tea consumption and risk of head and neck cancer.

BACKGROUND: The current study evaluated the association between tea consumption and head and neck cancer (HNC) in Taiwan, where tea is a major agricultural product and a popular beverage. METHODS: Interviews regarding tea consumption (frequency, duration, and types) were conducted with 396 HNC cases and 413 controls. Unconditional logistic regression was performed to estimate the odds ratio (OR) and 95% confidence interval (CI) of HNC risk associated with tea drinking, adjusted for sex, age, education, cigarette smoking, betel quid chewing, and alcohol drinking. RESULTS: A reduced HNC risk associated with tea drinking (OR for every cup per day = 0.96, 95% CI: 0.93-0.99; OR for ≧5 cups per day = 0.60, 95% CI: 0.39-0.94) was observed. The association was especially significant for pharyngeal cancer (OR for every cup per day = 0.93, 95% CI: 0.88-0.98; OR for ≧5 cups per day = 0.32, 95% CI: 0.16-0.66). A significant inverse association between HNC and tea consumption was observed particularly for green tea. CONCLUSIONS: This study suggests that tea drinking may reduce the risk of HNC. The anticancer property of tea, if proven, may offer a natural chemopreventive measure to reduce the occurrence of HNC.

The interplay between alcohol consumption, oral hygiene, ALDH2 and ADH1B in the risk of head and neck cancer.

Alcohol consumption is an established risk factor for head and neck cancer (HNC). The major carcinogen from alcohol is acetaldehyde, which may be produced by humans or by oral microorganisms through the metabolism of ethanol. To account for the different sources of acetaldehyde production, the current study examined the interplay between alcohol consumption, oral hygiene (as a proxy measure for the growth of oral microorganisms), and alcohol-metabolizing genes (ADH1B and ALDH2) in the risk of HNC. We found that both the fast (*2/*2) and the slow (*1/*1+ *1/*2) ADH1B genotypes increased the risk of HNC due to alcohol consumption, and this association differed according to the slow/non-functional ALDH2 genotypes (*1/*2+ *2/*2) or poor oral hygiene. In persons with the fast ADH1B genotype, the HNC risk associated with alcohol drinking was increased for those with the slow/non-functional ALDH2 genotypes. For those with the slow ADH1B genotypes, oral hygiene appeared to play an important role; the highest magnitude of an increased HNC risk in alcohol drinkers occurred among those with the worst oral hygiene. This is the first study to show that the association between alcohol drinking and HNC risk may be modified by the interplay between genetic polymorphisms of ADH1B and ALDH2 and oral hygiene. Although it is important to promote abstinence from or reduction of alcohol drinking to decrease the occurrence of HNC, improving oral hygiene practices may provide additional benefit.