Social networking website increases efficacy and engagement in a distance learning course about oral lesions.

PURPOSE: Distance learning appears to be an attractive approach to continuing education courses, but one barrier is maintaining learner engagement throughout the course. The primary aim of this research was to evaluate the operational efficacy of a private Facebook™ group (FG) in serving as a support mechanism for distance learning courses, and its impact on three fundamental dimensions: the attrition rates of participants who did not complete the course (commonly referred to as dropout rates), the rates of course completion and approval, and the overall performance of the participants. METHODS: The participants of this quasi-experimental study comprised 159 dental students and 565 dentists enrolled in an e-learning course on oral mucosal lesion diagnosis. Prior to the initiation of the course, all participants were provided with the option to join a private FG. Within this group, moderators shared motivational messages and provided reminders concerning deadlines. Moreover, participants had the opportunity to engage in interactive discussions pertaining to topics related to the course. The course itself followed a self-guided format, employing the flipped-classroom methodology, spanning a total of 50 instructional hours. In order to assess the effectiveness of the course, participants were presented with photographs illustrating 30 oral lesions and were asked to propose diagnostic hypotheses both before and after the educational intervention (pre-tests and post-tests). RESULTS: Dentists who participated in the FG exhibited a significantly lower rate of discontinuation. As for dental students, their involvement in the group was positively associated with better performance, as determined by the percentage of accurate diagnostic hypotheses (a minimum of 70% correct responses was required for their approval in the course). CONCLUSIONS: Facebook™ demonstrates promise as a supplementary pedagogical tool in distance education courses. The interactive nature of the platform has the potential to alleviate the inherent challenges of remote learning.

Periodontal disease affects oral cancer progression in a surrogate animal model for tobacco exposure.

For decades, the link between poor oral hygiene and the increased prevalence of oral cancer has been suggested. Most recently, emerging evidence has suggested that chronic inflammatory diseases from the oral cavity (e.g., periodontal disease), to some extent, play a role in the development of oral squamous cell carcinoma (OSCC). The present study aimed to explore the direct impact of biofilm­induced periodontitis in the carcinogenesis process using a tobacco surrogate animal model for oral cancer. A total of 42 Wistar rats were distributed into four experimental groups: Control group, periodontitis (Perio) group, 4­nitroquinoline 1­oxide (4­NQO) group and 4NQO/Perio group. Periodontitis was stimulated by placing a ligature subgingivally, while oral carcinogenesis was induced by systemic administration of 4NQO in the drinking water for 20 weeks. It was observed that the Perio, 4NQO and 4NQO/Perio groups presented with significantly higher alveolar bone loss compared with that in the control group. Furthermore, all groups receiving 4NQO developed lesions on the dorsal surface of the tongue; however, the 4NQO/Perio group presented larger lesions compared with the 4NQO group. There was also a modest overall increase in the number of epithelial dysplasia and OSCC lesions in the 4NQO/Perio group. Notably, abnormal focal activation of cellular differentiation (cytokeratin 10­positive cells) that extended near the basal cell layer of the mucosa was observed in rats receiving 4NQO alone, but was absent in rats receiving 4NQO and presenting with periodontal disease. Altogether, the presence of periodontitis combined with 4NQO administration augmented tumor size in the current rat model and tampered with the protective mechanisms of the cellular differentiation of epithelial cells.

BDNF/TrkB/Akt Signaling Pathway Epithelial Odontogenic Tumors and Keratocyst: An Immunohistochemical Study Comparative With Dental Germs.

Odontogenic lesions (OL) are an important group of oral and maxillofacial diseases represented by odontogenic cysts, benign, and malignant tumors. The brain-derived neurotrophic factor (BDNF)/ tropomyosin receptor kinase B (TrkB) signaling pathway has multiple biological actions and has been identified as an important pathway in the proliferation, invasion, and survival of different epithelial tumors. Its role in the development of OL, however, has so far been unexplored. Our aim was to evaluate the BDNF/TrkB/Akt/p-RPS6 signaling pathway in OL of epithelial origin. This cross-sectional study comprised 3 cases of tooth germs, 25 cases of odontogenic keratocyst (OK), 29 cases of ameloblastoma (Am), and 6 cases of ameloblastic carcinoma. Immunohistochemical staining for BDNF, TrkB, p-Akt, and p-RPS6 was performed. OLs were evaluated according to the pattern of immunohistochemical expression in epithelial cells and by semiquantitative scores that considered the intensity of staining and percentage of positive cells. BDNF stromal expression was also assessed. No significant differences were observed with respect to the percentage of positive cases for all markers. Regarding the immunoreactive scores, BDNF and p-RPS6 expressions were similar in the odontogenic epithelium of all OL. However, TrkB and p-Akt were overexpressed in OK compared with ameloblastic carcinoma. In Am, epithelial BDNF was significantly higher compared with stromal expression. In conclusion, BDNF seems to participate in the development of cystic, benign, and malignant odontogenic epithelium to similar degrees. The acquisition of the invasive or malignant phenotype in odontogenic neoplasms is not associated with alterations in the BDNF/TrkB/Akt/RPS6 axis, which could be implicated in the differentiation process.

Continuing education activities improve dentists' self-efficacy to manage oral mucosal lesions and oral cancer.

OBJECTIVES: This cross-sectional study aims to evaluate whether Continuing Education Activities (CEA) influence dentists' behaviour in relation to oral lesions. The secondary aim is to assess the association between dentists' perception of learning adequacy and self-efficacy for oral mucosal lesion management. METHODS: A self-administered online questionnaire was conducted on dentists working at the public health system of Rio Grande do Sul State, Brazil. The questionnaire included questions pertaining to perception of adequacy for oral diagnosis classes upon graduation, participation in oral cancer CEA and self-efficacy in managing oral mucosal lesions. RESULTS: 221 dentists from 91 municipalities answered the questionnaire. Most participants were female (71.5%) with a mean age of 38.3 years. Perception of learning as adequate during undergraduate coursework was associated with self-efficacy to diagnose, biopsy, and treat oral mucosal lesions (P < .05, Chi-squared test). However, 83.3% of dentists considered the time devoted to these topics prior to graduation insufficient. The frequency of oral lesion detection was related to self-efficacy to treat oral lesions and detecting oral cancer (P < .05, Chi-squared test). Among dentists who detected oral lesions frequently, 88.9% had attended CEA, whereas 11.1% of them had never attended these activities. CONCLUSIONS: CEA may improve awareness and efficacy of primary healthcare professional's detection of oral cancer.

Can propranolol act as a chemopreventive agent during oral carcinogenesis? An experimental animal study.

The multistep process of oral carcinogenesis provides a biological rationale for the use of chemoprevention in individuals at increased risk of developing oral cancer. We aimed to determine if low doses of propranolol can prevent the development of oral cancer using a tobacco-relevant and p53-associated animal model of cancer initiation. Twenty-six Wistar rats were randomly allocated into two groups, vehicle, and propranolol. All animals received 4-nitroquinoline N-oxide (4NQO) at 25 ppm diluted in the drinking water for 20 weeks. Animals from the propranolol group received propranolol (0.1 mg/kg) 5 days per week by gavage for 18 weeks. The clinical analysis was performed by measuring the area of the lesion and assessment of scores based on lesion appearance (papule; plaque; nodule or ulcerated). Histopathological analysis was performed to determine the presence of epithelial dysplasia or invasive squamous cell carcinoma (SCC). The average lesion area in 4NQO + vehicle and in 4NQO + propranolol groups were 0.20 and 0.28 mm2, respectively (P = 0.53). The percentage of cases clinically graded as papules, thick plaques, nodular areas, and ulcerated lesions was similar between groups (P = 0.94). Histopathological diagnosis also did not differ between groups (P = 0.65), with 54.5 and 70% of cases being diagnosed as SCC in 4NQO and in 4NQO + propranolol groups, respectively. In conclusion, daily doses propranolol at 0.1 mg/kg were not as effective as a chemopreventive therapy in an animal model of 4NQO-induced carcinogenesis.

Effect of red wine and its major components on periodontitis and systemic inflammation in rats.

OBJECTIVES: To evaluate the influence of red wine exposure, alcohol, grape juice and resveratrol in the occurrence of spontaneous and ligature induced periodontitis as well as CRP, TNFα and IL-6 levels in Wistar rats. METHODOLOGY: 50 male Wistar rats were randomly assigned to 5 groups (Control, Red Wine, Grape Juice, 12% Alcohol and 0.05mg/mL Resveratrol). All groups were fed with laboratory rat chow and liquid intake according to group allocation. After 8 weeks, ligatures were placed around the maxillary right second molars. The contra-lateral molars remained as intra-group controls. After 14 days, animals were killed, blood samples collected and specimens prepared for analysis. Group comparisons were performed by ANOVA. A cut-off point in the 75th percentile in the side without ligature was used for definition of spontaneous periodontitis. RESULTS: All animals completed the experiment. According to mean alveolar bone loss, no statistically significant differences were found. Animals exposed to red wine presented a lower occurrence of spontaneous periodontitis, lower levels of TNF-α (0.97 ng/mL) and CRP (0.29 mmol/µL) compared to controls (1.97 ng/mL, p = 0.008 and 0.45 mmol/ µL, p less than or equal to 0.05 respectively). CONCLUSION: Red wine exposure potentially affects the occurrence of spontaneous periodontitis, CRP and TNF-α levels in Wistar rats.

Spontaneous alveolar bone loss after 4NQO exposure in Wistar rats.

OBJECTIVE: This study evaluated the effect of an experimental carcinogenic, 4-Nitroquinoline 1-oxide (4NQO), in the spontaneous alveolar bone loss (ABL) in an animal model. DESIGN: Twenty-two male Wistar rats were included in this study. They were randomly divided into two groups: the control group (n = 10) received food and water ad libitum, and the test group (n = 12) receive the same food; however, 25 ppm of 4NQO was diluted in the drinking water. All animals were euthanized after 20 weeks, and the tongues were removed and analyzed macroscopically to determine the presence of oral mucosal lesions. All specimens were paraffin-embedded and histological sections were obtained. The microscopic analysis was based on routine procedure (haematoxylin and eosin stain). The analysis of spontaneous ABL was performed by a calibrated examiner using standardized photographs and imaging software. Differences in spontaneous ABL were assessed among the three resulting groups: control, 4NQO with oral squamous cell carcinoma (OSCC), and 4NQO without OSCC. RESULTS: In the 4NQO-treated group, nine animals developed OSCC. The animals in the 4NQO with OSCC group presented significantly more spontaneous ABL (0.65 ±â€¯0.21 mm) than the control group (0.34 ±â€¯0.05) (p < 0.001). The animals in the 4NQO without OSCC group showed a mean spontaneous ABL of 0.47 ±â€¯0.13 mm, which was not statistically significant different when compared to the control group (p = 0.096). CONCLUSIONS: It was concluded that the presence of OSCC enhanced spontaneous ABL in Wistar rats when compared to control animals. Additionally, it was shown that, solely, administration of 4NQO may not be considered responsible for alveolar bone destruction.

A clinical diagnosis of oral leukoplakia; A guide for dentists

Background: In view of the many white or predominantly white lesions of the oral mucosa it is a challenge for dentists to clinically identify a leukoplakia, being a potentially (pre)malignant lesion. Material and Methods: Based on the available literature and experience of the authors the parameters of a clinical diagnosis of oral leukoplakia have been studied. Results: A guide has been presented that should help dentists to establish a clinical diagnosis of leukoplakia as accurate as possible. Conclusions: Probably in most parts of the world dentists will need the help of a specialist for confirmation or exclusion of the clinical diagnosis of oral leukoplakia and for further management of the patient, including patient information (AU)

No disponible

Angina bullosa hemorrhagica: report of 7 cases and analysis of 199 cases from the literature.

Angina bullosa hemorrhagica (ABH) is a condition characterized by blood blisters in the oral or oropharyngeal mucosa. Typically, the first presentation of ABH is acute, and rupture of the blisters occurs after a few hours or days. Although its etiology is unclear, ABH is assumed to be associated with predisposing factors such as local trauma or chronic use of inhaled steroids. The diagnosis is defined clinically, based on the presentation and evolution of the lesions. The recommended treatment is symptomatic, but extensive lesions may present a risk of airway obstruction and may require surgical excision. This case series reports 7 cases of ABH and reviews 199 cases published in the English-language literature. The possible etiologic factors, predisposing factors, and differential diagnoses are discussed.

Hypoacetylation of acetyl-histone H3 (H3K9ac) as marker of poor prognosis in oral cancer.

AIMS: Epigenetics refers to changes in cell characteristics that occur independently of modifications to the DNA sequence. Oral carcinogenesis is influenced by modifications in epigenetic mechanisms, including changes in histones, which are proteins that support chromatin remodelling for the dynamic regulation of gene expression and silencing. The dysregulation of histone acetylation can lead to the uncontrolled activity of different genes, thereby triggering events associated with malignant transformation. The aim of this study was to analyse the expression of acetyl-histone H3 at lys9 (H3K9ac) in oral leucoplakia (OL) and oral squamous cell carcinoma (OSCC) in addition to its association with cell proliferation, epithelial-mesenchymal transition (EMT) and clinical-pathological findings. METHODS AND RESULTS: Samples of normal oral mucosa (NOM), OL and OSCC were submitted to immunohistochemical analysis using anti-H3K9ac, Ki67 and vimentin. Slides were submitted to quantitative analysis regarding the percentage of positive cells. OSCC presented less expression of H3K9ac in comparison to OL (P < 0.01), whereas Ki67 and vimentin levels increased from OL to OSCC (P < 0.001 and P = 0.03, respectively). OSCC patients with poor prognosis had less H3K9ac expression (P = 0.04). The Kaplan-Meier cumulative survival curves also revealed lower survival rates in patients with less H3K9ac expression (P < 0.01). CONCLUSIONS: The present findings suggest that changes in H3K9ac occur during the process of oral carcinogenesis along with an increase in cell proliferation and EMT. The results demonstrate that H3K9ac may be a useful novel prognostic marker for OSCC.

Immunohistochemical Study of TGF-ß1 in Oral Leukoplakia and Oral Squamous Cell Carcinoma: Correlations Between Clinicopathologic Factors and Overall Survival.

The aim of the present study was to analyze transforming growth factor ß1 (TGF-ß1) expression in cases of leukoplakia and oral squamous cell carcinoma (OSCC) and to correlate these expression profiles with proliferative labeling index, clinicopathologic factors, and clinical outcome. Clinical data for 24 cases of leukoplakia and 87 cases of OSCC were retrieved from medical records. OSCC tissues were included into tissue microarray blocks and sections of normal mucosa, leukoplakia, and OSCC tissue microarray's were prepared on slides. Immunohistochemistry was used to detect expression of TGF-ß1 and Ki67. The expression of TGF-ß1 and Ki67 were significantly increased from normal mucosa, through leukoplakia to OSCC. High expression of TGF-ß1 correlated with an increase in proliferative labeling index. No association between TGF-ß1 expression and the clinicopathologic factors examined was observed. Expression of TGF-ß1 also did not associate with clinical outcome in either of groups. Our results suggest that changes in TGF-ß1 are associated with the progression of oral carcinogenesis.

Teledentistry: A Tool to Promote Continuing Education Actions on Oral Medicine for Primary Healthcare Professionals.

BACKGROUND: Difficulties in diagnosis of oral mucosal lesions are a significant cause of delayed oral cancer diagnosis, and this difficulty may be due to gaps in knowledge. This study evaluated the diagnostic skills of primary healthcare professionals regarding oral cancer and presented them with an e-learning course. MATERIALS AND METHODS: Forty-seven primary healthcare professionals (32 dentists and 15 nondentists) enrolled in a 24-h course on oral medicine delivered through an e-learning platform. A test, based on 33 clinical images of oral lesions, was used to evaluate the diagnostic skills of participants. The participants were requested to classify each lesion as benign, potentially malignant, or malignant as well as to inform their clinical impression. Three specialists also took the test as the gold standard. RESULTS: Twenty-seven participants completed the test. Nondentists and dentists showed a comparable sensitivity of 68.8 ± 11.1 and 63.7 ± 15.8, respectively. Specialists performed somewhat better; however, the difference was not statistically significant (81.0% ± 4.1%, p = 0.16). Dentists and specialists (70.0% ± 16.6% and 95.5% ± 3.1%, respectively) showed higher specificity than nondentists (39.3 ± 20.6, p < 0.01). Nondentists had a higher number of unanswered questions (p < 0.01) for classification and clinical impression (50.0% ±45.1% and 72.0% ± 25.0%, respectively) than dentists (5.7% ±11.9% and 19.8% ± 20%, respectively). Both dentists and nondentists had low attendance in the course (44.57% ± 37.38% and 26.53% ± 26.53%, respectively, p = 0.26). To the best of our knowledge, this is the first study to assess the diagnostic skills of public health workers belonging to different professional categories. CONCLUSION: Both dentists and nondentists have a fairly good capacity for discriminating the nature of oral lesions. Early squamous cell carcinoma is the most challenging situation and remains an issue to be addressed.

Proliferative verrucous leukoplakia; a critical appraisal of the diagnostic criteria

Since its introduction in the literature in 1985, the term proliferative verrucous leukoplakia (PVL) has been the subject of an ongoing discussion with regard to its definition. Widespread or multifocal occurrence of oral leukoplakiais not just synonymous to PVL. In the present treatise the proposal is made to require the involvement of more than two oral oral subsites, a total added seize of the leukoplakic areas of at least 3 centimeters, and a well documented period of at least five years of disease evolution being characterized by spreading and the occurrence of one or more recurrences in a previously treated area (AU)

Proliferative verrucous leukoplakia; a critical appraisal of the diagnostic criteria.

Since its introduction in the literature in 1985, the term proliferative verrucous leukoplakia (PVL) has been the subject of an ongoing discussion with regard to its definition. Widespread or multifocal occurrence of oral leukoplakia is not just synonymous to PVL. In the present treatise the proposal is made to require the involvement of more than two oral oral subsites, a total added seizeof the leukoplakic areas of at least 3 centimeters, and a well documented period of at least five years of disease evolution being characterized by spreading and the occurrence of one or more recurrences in a previously treated area.

Effect of topical chamomile on immunohistochemical levels of IL-1ß and TNF-α in 5-fluorouracil-induced oral mucositis in hamsters.

PURPOSE: The aim of the present study was to evaluate the effect of topical chamomile and corticosteroid treatment on the profile of tissue cytokines (IL-1ß and TNF-α) in 5-fluorouracil-induced oral mucositis in hamsters. METHODS: Thirty-six hamsters were randomly separated into three groups (12 animals each): Group I--without treatment (control); Group II-treatment with chamomile (Ad-Muc(®)); and Group III--treatment with corticosteroid (betamethasone elixir- Celestone(®)). The animals received an intraperitoneal injection of 5--fluorouracil on Days 0 and 2. On Days 3 and 4, the buccal mucosa was scratched and therapy was initiated on Day 5. Three animals from each group were killed on Days 0, 5, 10, and 14 and the buccal mucosa was removed. The streptavidin-biotin complex method was used to delineate the in situ distribution, localization, and semiquantitative analysis of IL-1ß and TNF-α. Data from the semiquantitative analysis of immunohistochemical staining were comparatively analyzed using the Kruskal-Wallis test, followed by Dunn's multiple comparisons test. RESULTS: The distribution and localization of IL-1ß and TNF-α immunolabeling were similar. These proteins exhibited a diffuse pattern distributed throughout the connective tissue. The epithelium and adipose tissue were negative for both proteins. The semiquantitative analysis revealed that immunolabeling of IL-1ß and TNF-α increased in all groups with the development of mucositis. On Day 10 (period of peak mucositis), the group treated with chamomile had lower scores for both pro-inflammatory cytokines. CONCLUSIONS: Treatment with topical chamomile reduced the tissue levels of IL-1ß and TNF-α, thereby demonstrating anti-inflammatory action in oral mucositis in hamsters.

Exploring the mechanisms of alcohol-related damage in oral mucosa - is oxidative stress associated with the increase in cell proliferation in rat tongue epithelium?

CONTEXT: Alcohol consumption has been related to a cell proliferation increase in oral epithelium but its mechanism remains unclear. OBJECTIVE: The aim of this study was to investigate whether oxidative stress parameters are implicated in the induction of cell proliferation in rat tongue epithelium after different times of chronic alcohol consumption. MATERIALS AND METHODS: Cell proliferation was assessed in tongue epithelium using AgNOR (argyrophilic proteins related to active nucleolar organizer regions) quantification. Oxidative stress parameters [lipid peroxidation, protein carbonyls, superoxide dismutase activity and catalase (CAT) activity and immunocontent] and Nrf2 immunocontent were quantified in tongue homogenates. RESULTS AND DISCUSSION: Mean AgNOR numbers (mAgNOR) per nucleus was 2.22 ± 0.30 in ventral tongue epithelium after 120 days of alcohol consumption (vs. 1.87 ± 0.18 for control animals and 1.91 ± 0.23 for animals treated with alcohol for 60 days) indicating cell proliferation increase (p < 0.05, ANOVA followed by Tukey post hoc). Interestingly, 60 days of alcohol consumption induced changes in oxidative stress parameters, but no alteration in cell proliferation. Vitamin E co-treatment was conduced in order to evaluate its possible protective effects. The 120 day Tween + vitamin E + alcohol treatment induced an increase in mAgNORs when compared to the Tween + vitamin E treated group (respectively 2.10 ± 0.30 vs. 1.77 ± 0.11, p < 0.05, ANOVA followed by Tukey post hoc), showing that vitamin E co-treatment had no protective effects. In addition, an inverse association was observed between CAT activity and AgNORs quantity (R = -0.32; p < 0.05, Person's correlation) as well as the possible involvement of Nrf2 in alcohol-related damage. CONCLUSIONS: Our findings suggest that the increase in cell proliferation associated with alcohol-related damage has no direct relation with an imbalance in oxidative parameters. In contrast, our results indicate that hydrogen peroxide may be implicated in cellular signaling during proliferation in the oral mucosa.

Oral health status in elders from South Brazil: a population-based study.

OBJECTIVE: To assess the oral health status of community-dwelling adults aged 60 years and older from southern Brazil and to determine demographics, socioeconomic, behavioural and dental risk indicators. MATERIALS AND METHODS: This cross-sectional study used a multistage, probability sampling method to draw a representative sample of the metropolitan area of Porto Alegre, Brazil. A subsample of 217 subjects was included in this analysis. Oral mucosal lesions, dental caries, tooth loss and periodontal status (full-mouth, six sites per tooth exam) were assessed by calibrated examiners. RESULTS: Prevalence of edentulism was 39.5%, and mean tooth loss was 20.2 (SE = 0.6). Older individuals [Odds Ratio (OR) = 2.2], women (OR = 2.3), white people (OR = 5.9), individuals of lower socioeconomic status (OR = 5.6) and smokers (OR = 3.5) had higher likelihood of being edentulous. Approximately 36% of dentate individuals had caries and/or restoration affecting, in average, 5.0 teeth. Periodontitis affected 79% of subjects, and it was associated with older age (OR = 4.0), men (OR = 3.4) and large amounts of supragingival plaque (OR = 3.0). CONCLUSION: Poor oral health was observed in this elderly population from South Brazil. Sociodemographic disparities accounted for most of the burden of disease and treatment needs.