Investigating the health disparities in the association between lifestyle behaviors and the risk of head and neck cancer.

Many studies have reported a positive association between lower socioeconomic status (SES) and higher head and neck cancer (HNC) risk. Fewer studies have examined the impact of SES on the association between alcohol or cigarette use and HNC risk. The current case-control study (1104 HNC cases and 1363 controls) investigated the influence of education, a SES indicator, on the association between HNC and the use of alcohol, cigarettes, or betel quids in Taiwan, a country with universal health care. Our results showed a larger increase in HNC risk associated with alcohol among those with lower educational level (odds ratio [OR] = 2.07; 95% confidence interval [CI], 1.53-2.80) than those with higher educational level (OR = 1.38; 95% CI, 1.04-1.85) (heterogeneity-P = .03). Educational level had an influence on the association between alcohol use and HNC risk among those with genetic susceptibility (ALDH2-deficient) to the carcinogenic effect of alcohol. The association between cigarette or betel quid use and HNC risk was similar between the high and low educational groups. National policies and social interventions have led to the decline in the prevalence of cigarette and betel quid users in Taiwan. In contrast, due to the lack of adequate alcohol control policies, alcohol consumption in Taiwan has continued to rise. A higher impact of alcohol on HNC risk among lower SES individuals even with universal health care could be the result of insufficient alcohol control policies in Taiwan.

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.

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.

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.

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.

Outcome Analysis and Unexpected-Scenario Prediction in 2-Stage Orthodontic Lower Third Molar Extraction.

PURPOSE: We propose a 2-stage orthodontic lower third molar extraction procedure to reduce iatrogenic inferior alveolar nerve injury. We tested our hypothesis that there are factors that can predict both dislodgement of the root portion and limited traction distances. PATIENTS AND METHODS: Fifteen patients (mean age, 25.7 years; age range, 17 to 65 years) with 20 lower third molars were enrolled. Panoramic films and cone beam computed tomography were analyzed. Dislodgement of the root portion, traction distance, duration of the orthodontic phase, and postoperative complications were documented. The predictive factors were analyzed and discussed. RESULTS: Three teeth had dislodgements of the root portion. The mean traction duration was 59.2 days (range, 33 to 77 days), and the mean traction distance was 2.60 mm (range, 0.27 to 5.20 mm). Root apex cortical bone indentation and root curvature were significantly associated with traction distance. Pulpitis symptoms were documented in 1 tooth, and no postoperative nerve disturbances occurred. CONCLUSIONS: Our proposed 2-stage orthodontic lower third molar extraction procedure reduced iatrogenic inferior alveolar nerve injury. Cortical bone indentation and root curvature predicted dislodgement of the root portion and limited traction distances.

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.

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.

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.

High-level ß1-integrin expression in a subpopulation of highly tumorigenic oral cancer cells.

OBJECTIVES: The ß1 integrin (CD29) is a putative marker for cancerous epithelial stem cells. Cancer stem cells are essential to drive tumor growth, recurrence, and metastasis. We investigated the role of ß1-integrin expression in the development of malignant phenotypes of oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Immunostaining was used to analyze the expression levels of ß1 integrins in different types of cell colonies and tumor spheres. The results of cell viability and migration assays with and without siRNA knockdown of ß1-integrin expression were compared. Cells expressing ß1 integrins were evaluated for their tumorigenicity in mice. The expression of ß1 integrins in human specimens of oral cancers at different clinical stages was semiquantified based on immunohistochemical staining of the ß1-integrin protein. RESULTS: The expression level of ß1 integrins in Meng-1 oral epidermoid carcinoma cells (OECM-1) cells was significantly higher in holoclonal colonies and tumor spheres compared to control cells. The knockdown of ß1-integrin expression in OECM-1 cells reduced cell proliferation, migration, and tumor sphere formation. Beta-1 integrin (+) cells were more tumorigenic in the mouse xenograft model than ß1 integrin (-) cells. In the human specimens, the expression level of the ß1-integrin protein positively correlated with the clinical stage. CONCLUSION: The expression of ß1 integrin in OECM-1 cells is involved in the development of malignant phenotypes of OSCC. CLINICAL RELEVANCE: Inhibitors for ß1-integrin signaling may be suitable to become target-specific therapies for OSCC.

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.

Investigating the association between serum human papillomavirus type 16 E7 antibodies and risk of head and neck cancer.

Human papillomavirus (HPV) is recognized as a major cause of oropharyngeal cancer (OPC) in Western countries. Less is known regarding its contribution to the OPC occurring in Asia. The current study aimed to investigate the association between antibody responses to HPV16 E7 and head and neck cancer (HNC) risk in a hospital-based case-control study conducted in Taiwan with 693 HNC cases and 1,035 controls. A positive association was observed between seropositivity to HPV16 E7 and OPC risk, whereas no significant association was found in the non-OPC cases. The increased OPC risk associated with seropositivity to HPV16 E7 was more significant among nonbetel quid or noncigarette users. Seropositivity to HPV16 E7 showed moderate agreement with P16 expression in OPC. OPC patients that were seropositive to HPV16 E7 or p16 positive were more highly educated and less likely to use alcohol, betel quids, and cigarettes compared to HPV16 E7 seronegative or p16 negative OPC patients. Furthermore, patients with p16 positive OPC were more likely to be women compared to patients with p16 negative OPC, likely owing to the low prevalence of alcohol, betel quid, and cigarette users among women. Overall, this study suggested that similar to Western countries, HPV may also be an important risk factor of OPC in Taiwan. With the declining consumption of betel quids and cigarettes in Taiwan, a higher percentage of OPC cases in Taiwan will be attributed to HPV in the future. Public health measures, including HPV vaccination, need to be implemented to prevent the occurrence of HPV-positive OPC.

Amyotrophic lateral sclerosis presenting as the temporomandibular disorder: A case report and literature review.

BACKGROUND: Spasticity and pain in the masticatory muscles or mouth opening limitation have been reported as early signs and symptoms of amyotrophic lateral sclerosis (ALS). These signs and symptoms are also frequently seen in, and thus mistaken for, temporomandibular disorders (TMD). CLINICAL PRESENTATION: The authors report a case of ALS initially presenting with signs and symptoms of TMD. The TMD was followed by dysarthria of insidious onset, leading to the diagnosis of ALS. This case highlights the importance of considering TMD as a potential early form of presentation of ALS, requiring multidisciplinary treatment, especially by dental professionals. CONCLUSION: A review of the literature was conducted to elucidate the oral and facial signs and symptoms of ALS and to identify ways of improving the quality of life of patients through a multidisciplinary approach.

Effects of Restorative Materials on Dental Pulp Stem Cell Properties.

INTRODUCTION: Dental pulp stem cells (DPSCs) are multipotent progenitors for biotechnological practices, but the influences of existing restorations on their viability and differentiation are not well-known. This study was aimed to investigate in vivo and in vitro responses of DPSCs to restorative materials. METHODS: Class I cavities were prepared on molars scheduled to be extracted and then restored with a resin-based composite (RBC), a glass ionomer cement, or zinc oxide eugenol. Intact teeth were used as controls. Twelve molars in each group were extracted on day 7 or day 30 after restorations to assess the early or intermediate pulp responses and were then cut in half. One half was processed for histopathological analysis, and the other was used to isolate DPSCs for a colony-forming unit assay and real-time polymerase chain reaction for NANOG, OCT4, and CD44 expression. RESULTS: All restored teeth showed pulp damage at various levels, whereas mild to moderate inflammation persisted in the RBC group until day 30. The existence of DPSCs in the pulp cores of all groups was revealed based on CD44 immunoreactivity. Glass ionomer cement and zinc oxide eugenol did not affect the relative percentages of DPSCs in either early or intermediate stages, whereas RBCs reduced the percentage. The colony-forming units in all restoration groups were comparable with those in the control. Nevertheless, the restorations significantly enhanced OCT4 expression, especially in RBC/day 30. CONCLUSIONS: Dental restorations cause mild pulp damage but do not affect DPSC viability. RBC decreases DPSC densities but might increase the stemness of surviving DPSCs through an inflammation-stimulation process.

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.

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.

Tumor-associated Hypercalcemia in a patient with Paget's disease.

Paget's disease of the bone, which is characterized by a focal region of highly exaggerated bone remodeling, is very rare in Asia. Most patients with Paget's disease are asymptomatic; they are normocalcemic and show elevated alkaline phosphatase levels. Hypercalcemia in patients with Paget's disease has rarely been reported. We report one Chinese patient with Paget's disease involving the maxilla bone with an initial presentation of facial cellulitis. Asymptomatic hypercalcemia with a low-normal intact parathyroid hormone level developed 9 years later. After clodronate treatment, the level of alkaline phosphatase normalized, but the hypercalcemia did not respond adequately. After analysis of tumor markers and imaging studies, a clinical diagnosis of pancreatic adenocarcinoma with multiple hepatic and lung metastases with pleural effusion was made. We suggest that malignancy-associated hypercalcemia should be considered as one of the causes of hypercalcemia in patients with Paget's disease.

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.

The outcome expectancy model for areca-quid chewing behavior.

Outcome expectancies as regards areca-quid chewing played an important role in areca-quid addiction. In this study, areca-quid user expectancies will be explored. A total of 179 adolescents selected from high school completed the areca-quid chewing expectancy questionnaire and related chewing-behavior scale. Three factors (physical/emotional reward, negative consequences and social benefit) relating to areca-quid chewing behavior were explored by factor analysis and the two-dimensional model of chewing expectancy (positive-negative effect of chewing and physical-social reaction to chewing) was found using non-metric multi-dimensional scaling. The structure of the areca-quid chewing expectancy was determined for an adolescent group and the social factors involved in areca-quid chewing clearly warrant further investigation.

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.