Can SARS-CoV-2 screening in oral biopsies aid epidemiological surveillance?

BACKGROUND: Three years after the first confirmed COVID-19 case in Brazil, the outcomes of Federal government omissions in managing the crisis and anti-science stance heading into the pandemic have become even more evident. With over 36 million confirmed cases and nearly 700 000 deaths up to January 2023, the country is one of the hardest-hit places in the world. The lack of mass-testing programs was a critical broken pillar responsible for the quick and uncontrolled SARS-CoV-2 spread throughout the Brazilian population. Faced with this situation, we aimed to perform the routine SARS-CoV-2 screening through RT-qPCR of oral biopsies samples to aid in the asymptomatic epidemiological surveillance during the principal outbreak periods. METHODS: We analyzed 649 formalin-fixed paraffin-embedded oral tissue samples from five important oral and maxillofacial pathology laboratories from the north, northeast, and southeast geographic regions of Brazil. We also sequenced the whole viral genome of positive cases to investigate SARS-CoV-2 variants. RESULTS: The virus was detected in 9/649 analyzed samples, of which three harbored the Variant of Concern Alpha (B.1.1.7). CONCLUSION: Although our approach did not value aiding asymptomatic epidemiological surveillance, we could successfully identify a using FFPE tissue samples. Therefore, we suggest using FFPE tissue samples from patients who have confirmed diagnosis of SARS-CoV-2 infection for phylogenetic reconstruction and contraindicate the routine laboratory screening of these samples as a tool for asymptomatic epidemiological surveillance.

Tobacco Use, Attitudes, Knowledge, and Perception About Smoking Cessation Counseling Among Brazilian Dental Students: a Cross-Sectional Study.

The aim of this study was to evaluate the prevalence of tobacco use, exposure to secondhand smoke, and knowledge and perception about smoking cessation counseling among dental students in Brazil. A cross-sectional study was performed at the School of Dentistry, Universidade Federal de Pernambuco, Brazil. The Global Health Professions Student Survey (GHPSS) research instrument was used. In the second half of 2017, students from the 5th to the 10th semester were recruited to answer the anonymous and self-administered survey in classrooms. The data were tabulated and analyzed, and information about the variables was presented using descriptive statistics. The association between the variables was determined through the Chi-square test and binary logistic regression. Two hundred and twenty-four students answered the survey. More than 40% of the students had tried cigarettes at least once and 8.9% were current smokers. About 28% of the participants reported having been exposed to secondhand smoke in their home and 57.1% in other environments. Most students recognized that they are role models for society and believed they should receive training in smoking cessation counseling. However, only 12.5% of the students reported having received some formal training in this subject. In conclusion, although dental students are aware of the harmful effects of tobacco, there is still a lack of training in smoking prevention and control among these future professionals.

A multicenter study of oral sarcomas in Brazil.

OBJECTIVES: The aim of this study was to investigate the prevalence of oral sarcomas from geographic regions of Brazil. MATERIALS AND METHODS: A cross-sectional study was conducted on biopsies obtained from January 2007 to December 2016 at twelve Brazilian oral and maxillofacial pathology centres. Gender, age, evolution time, clinical aspects, tumour location, tumour size at diagnosis, radiographic aspects and histopathological diagnosis were evaluated. Data were analysed using descriptive statistical methods. RESULTS: From 176,537, a total of 200 (0.11%) oral sarcomas were reported, and the most prevalent were osteosarcomas (74 cases; 37%) and Kaposi's sarcomas (52 cases; 26%). Males were more affected than females at a mean age of 32.2 years old (range of 3-87 years). The most common symptoms were swelling¸ localised pain and bleeding at a mean evolution time of 5.14 months (range <1-156 months). The lesions were mostly observed in the mandible (90 cases; 45%), with a mean tumour size of 3.4 cm (range of 0.3-15 cm). Radiographically, the lesions presented a radiolucent aspect showing cortical bone destruction and ill-defined limits. CONCLUSIONS: Oral sarcomas are rare lesions with more than 50 described subtypes. Osteosarcomas and Kaposi's sarcomas were the main sarcomas of the oral cavity in Brazil.

KRAS mutations drive adenomatoid odontogenic tumor and are independent of clinicopathological features.

Adenomatoid odontogenic tumor is a benign encapsulated epithelial odontogenic tumor that shows an indolent clinical behavior. We have reported in a few adenomatoid odontogenic tumors mutations in KRAS, which is a proto-oncogene frequently mutated in cancer such as lung, pancreas, and colorectal adenocarcinomas. We aimed to assess KRAS mutations in the hotspot codons 12, 13, and 61 in a large cohort of adenomatoid odontogenic tumors and to test the association of these mutations with clinical (age, site, tumor size, follicular/extrafollicular subtypes) and histopathological parameters. Thirty eight central cases were studied. KRAS codon 12 mutations were assessed by TaqMan allele-specific qPCR (p.G12V/R) and/or Sanger sequencing, and codon 13 and 61 mutations were screened by Sanger. Histological tumor capsule thickness was evaluated by morphometric analysis. Additionally, the phosphorylated form of the MAPK downstream effector ERK1/2 was investigated. Statistical analysis was carried out to test the association of KRAS mutations with clinicopathological parameters. KRAS c.35 G >T mutation, leading to p.G12V, was detected in 15 cases. A novel mutation in adenomatoid odontogenic tumor, c.34 G >C, leading to p.G12R, was detected in 12 cases and the other 11 were wild-type. Codon 12 mutations were not associated with the clinicopathological parameters tested. RAS mutations are known to activate the MAPK pathway, and we show that adenomatoid odontogenic tumors express phosphorylated ERK1/2. In conclusion, a high proportion of adenomatoid odontogenic tumors (27/38, 71%) have KRAS codon 12 mutations, which occur independently of the clinicopathological features evaluated. Collectively, these findings indicate that KRAS mutations and MAPK pathway activation are the common features of this tumor and some cancer types. Although it is unclear why different codon 12 alleles occur in different disease contexts and the complex interactions between tumor genotype and phenotype need clarification, on the basis of our results the presence of KRAS p.G12V/R favors the adenomatoid odontogenic tumor diagnosis in challenging oral neoplasm cases.

Effects of chronic treatment with botulinum toxin type A in salivary glands of rats: Histological and immunohistochemical analyses.

BACKGROUND: The intraglandular application of botulinum neurotoxin type A (BoNT-A) is used in patients with neuromotor disorders to control the escape of saliva. The aim of this study was to analyze the impact of repeated treatment with BoNT-A on the submandibular-sublingual complex of rats. METHODS: A total of 35 Wistar rats were divided into three groups: control group (C), in which animals were not treated; group B, treated with 2.5 U intraglandular injections of BoNT-A (Prosigne® ) and group G, that received bovine gelatine (Prosigne stabilizer). Three applications were performed in intervals of 35 days. Twelve and 35 days after ending the treatment, submandibular-sublingual complex was collected for histological analysis. Immunohistochemical reactions for calponin and specific muscle actin were also performed, besides detection of apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. RESULTS: A decrease in mucosal and serous acini diameter was observed, with increased interstitial space after 12 days of treatment with BoNT-A, which was observed in a lesser degree on the 35th day. At 12 days, immunohistochemical analysis revealed a decrease in myoepithelial cells of serous acini in group B. TUNEL methods evidenced apoptosis in animals from group B. CONCLUSIONS: BoNT-A caused histological and cellular changes in submandibular-sublingual complex, followed by a tendency toward reversal after 35 days. The reversal characteristic of cellular changes in the submandibular-sublingual complex suggests that this BoNT-A formulation may be safely used for sialorrhea treatment.

Pesticides as risk factors for head and neck cancer: A review.

Humans may be exposed to pesticides such as fungicides, herbicides, and insecticides, during occupational and non-occupational activities. Pesticides could be related to cancer development mainly because of their effects on the endocrine and immune systems and their cumulative effect. The present review evaluated in current literature evidence of an association between exposure to pesticides and the occurrence of head and neck cancer (HNC). A literature search for cohort studies was conducted in the PubMed, Web of science, and Cochrane databases. Methodological quality of each study was rated with the Scottish Intercollegiate Guidelines Network (SIGN) checklist. One thousand one hundred and thirty-two studies were identified. Thirty-two were included. Most of the studies found addressed occupational exposure to pesticides and were conducted in Europe and North America. Eleven high-quality studies were found. Most of them found no association between exposure to pesticides and increased risk of HNC. Two studies found some evidence of a positive association between pesticide (malathion and atrazine) exposure and thyroid cancer. The literature review does not support a clear evidence for association between pesticides exposure and HNC. Only limited evidence points to a positive association between exposure to some pesticides and thyroid cancer. Further standardized studies based on appropriate designs are required to clarify the effect of pesticides on the genesis of HNC, considering dose, length of exposure, and type of pesticide.

Knowledge and attitudes of Brazilian dental students and dentists regarding bisphosphonate-related osteonecrosis of the jaw.

PURPOSE: The aim of this study was to evaluate the knowledge of Brazilian dentists (DEN) and dental students (DS) about bisphosphonates (BP) and bisphosphonate-related osteonecrosis of the jaw (BRONJ). METHODS: A convenience sample of 104 DEN and 100 DS was randomly selected and invited to answer a questionnaire. The questionnaire was structured on the basis of the main information about BP and the risk factors associated with the development of BRONJ. The data obtained were analyzed by the chi-square and Fisher's exact tests, considering significance of 5%. RESULTS: Seventy-five (72.1%) DEN and 75 (75%) DS did not know the BP cited in the questionnaire (p < 0.0001), and their commercial brand names were not recognized by 88 (84.6%) DEN and 86 (86%) DS (p < 0.0001). In the same way, 62 (59.6%) DEN (p = 0.04) and 58 (58%) DS (p < 0.0001) did not recognize BRONJ as an oral side effect of BP or point out oral conditions that were not associated with the use of BP. CONCLUSIONS: Practical initiatives, such as free lectures and workshops, must be taken to broaden the knowledge of DEN and DS about BP and thus contribute to the prevention of BRONJ.

Ionizing radiation effects on the secretory-stage ameloblasts and enamel organic extracellular matrix.

This study assessed the effects of high doses of ionizing radiation on eruption rate, odontogenic region morphology, secretory-stage ameloblasts, and enamel organic extracellular matrix (EOECM) of rat maxillary incisors. For the study, 30 male rats were divided into three experimental groups: control (non-irradiated), irradiated by 15 Gy, and irradiated by 25 Gy. Irradiated groups received a single dose of 15 or 25 Gy of X-rays in the head and neck region. The maxillary incisor eruption rate was measured. Sections of 5-µm thickness of the maxillary incisor odontogenic regions were evaluated using bright field light microscopy. Ultrathin sections of secretory ameloblasts and their EOECM were analyzed by transmission electron microscopy (TEM). Irradiated groups showed significantly diminished eruption rate values at the 4th and at the 6th day after irradiation. Reduced optical retardation values were observed in the irradiated groups. The odontogenic region of maxillary incisors from irradiated rats exhibited altered and poorly organized preameloblasts. TEM showed degeneration areas in the secretory-stage EOECM and several autophagosomes in the secretory ameloblasts from irradiated animals. In conclusion, high radiation doses delay eruption and induce disturbances in secretory ameloblasts and EOECM of rat maxillary incisors. These findings may be associated with structural defects of mature enamel.

Central Myoepithelioma of the Maxilla.

Myoepithelioma is a benign salivary gland tumor. Central myoepitheliomas are very rare. The aim of this report was to describe a case of maxillary myoepithelioma. A 14-year-old female patient presented with an multilocular lesion in the anterior maxilla, with nearly 8 months of duration. The lesion was asymptomatic, and the patient's dental history was unremarkable. The diagnostic hypothesis was an odontogenic tumor. Biopsy specimen consisted of nests of plasmacytoid cells in a myxoid stroma without duct formation. No cellular atypia or bone and cartilage formation were noted. The neoplastic cells were positive for Pan-cytokeratin, S100, CK7, and CK8. The final diagnosis was myoepithelioma. The patient was treated by surgical excision followed by bone curettage, and no signs of recurrence were found after 8 years of treatment.

Effects of the serjania erecta and zeyheria montana ethanol extracts in experimental pulpitis in rats: a histological study.

OBJECTIVES: The aim of this study was to evaluate, by the semi-quantitative histological analysis, the anti-inflammatory activity of the ethanolic extracts of Serjania erecta e Zeyheria Montana, in experimental pulpits in rats. STUDY DESIGN: In order to induce pulp inflammation, cavities were performed on the occlusal surface of the mandibular first molars of 45 male rats, without pulp exposure. The animals were distributed into 4 groups: GI, teeth without cavities; GII, single dose of saline solution via intraperitoneal (IP); GIII, single dose (IP) of 300 mg/Kg of ethanolic extract of Zeyheria montana; GIV, single dose (IP) of 300 mg/Kg of ethanolic extract of Serjania erecta. After 6, 12 and 24 hours, 5 animals of each group were killed by anesthetic overdose. The histological analyses of the pulp tissue were performed and the data analyzed by Dunn's multiple test, at significance of 5%. RESULTS: After 12 h, the GIII presented score statistically lower (p<0.05) than positive control group. After 24 h, GIII presented inflammatory index statistically lower than the positive control (p<0.01) and Serjania erecta (p<0.05) groups. CONCLUSION: The Zeyheria montana extract presented better anti-inflammatory activity than positive control group and Serjania erecta extract, which did not show anti-inflammatory effect in the analyzed periods.

Clinicopathological study and survival outcomes of sialoblastoma: A systematic review.

Sialoblastoma is a rare malignant salivary gland tumor. The aim of this study was to review the available published data on sialoblastoma in a comprehensive analysis of its clinicopathologic characteristics, treatment, and outcomes. An unrestricted electronic search was performed in the following databases: MEDLINE/PubMed, EMBASE, Scopus, Web of science, and gray literature databases. Eligibility criteria included publications with sufficient clinical, imaging, and histopathological information to confirm the diagnosis of sialoblastoma. Data were evaluated descriptively and analytically. A total of 52 studies met the eligibility criteria. In total, 62 patients were evaluated. There was no gender predilection, with the parotid being the most affected primary site (n = 28; 45.2%). In the log-rank test, there was a significant increase in disease-associated survival in patients younger than 1 year of age (82.8% vs. 44.4%; p = 0.003), individuals with lesions in major salivary glands (79.4% vs. 38.5%; p = 0.005), patients without metastases (77.8% vs. 14.3%; p = 0.011), encapsulated lesions (85.7% vs. 0%; p < 0.0001), congenital lesions (83.3% vs. 25.0%; p < 0.0001), and lesions that do not show perineural invasion (89.5% vs. 40%; p = 0.035). Kaplan-Meier curves estimated overall survival and disease-free survival at 5 years of 95.5% and 68.1%, respectively. In the multivariate Cox regression model, only the presence of metastasis was identified as an independent prognostic factor (hazard ratio [HR] = 9.81; p = 0.010). Although sialoblastoma presents good prognosis, the tumor has a high recurrence rate.

Crystal-storing histiocytosis: a rare lesion in periapical pathology.

Crystal-storing histiocytosis is a rare manifestation of plasma cell dyscrasia/monoclonal gammopathies and lymphoproliferative disorders, characterized by cytoplasmic accumulation of crystallized immunoglobulins in histiocytes. Nevertheless, some reported cases of crystal-storing histiocytosis raise the possibility that this lesion may also be reactive. Crystal-storing histiocytosis in the oral cavity is extremely rare; only one case affecting the tongue has been reported in the English-language literature. In this report, we discuss the case of a 38-year-old man who presented a persistent periapical lesion affecting the maxillary left lateral incisor. Histopathological analysis showed numerous crystal-laden histiocytes associated with a mild plasma cell infiltrate within a fibrous stroma. The plasma cells failed to show clonal light-chain restriction, and the patient had no associated hematologic disorder or systemic disease. Thus, this lesion was probably the result of hypersecretion of immunoglobulins by polyclonal plasma cells found in the periapical lesion. Crystal-storing histiocytosis should be considered in the differential diagnosis of periapical lesions.

Epiphany root canal sealer prepared with resinous solvent is irritating to rat subcutaneous tissues.

OBJECTIVE: This study assessed the biocompatibility of the Epiphany endodontic sealer prepared with resinous solvent of Epiphany system (Thinning resin) in rat subcutaneous tissues. STUDY DESIGN: Polyethylene tubes were filled with the sealer and 4 groups were established: GI, Epiphany prepared with 1 drop of resinous solvent (RS); GII, Epiphany prepared with 1 drop of RS and photoactivated; GIII, Epiphany associated with self-etch primer and prepared with 1 drop of RS; GIV, Epiphany associated with self-etch primer, prepared with 1 drop of RS and photoactivated. The filled tubes were implanted into 4 different regions of the dorsum of 20 adult male rats. RESULTS: After 7, 14 and 21 days, all groups presented a moderate to severe chronic inflammation, necrosis and foreign-body giant cells. At 42 days, although the intensity of chronic inflammatory reaction decreased, the other features still were observed. CONCLUSION: The Epiphany sealer prepared with the RS was irritating to rat subcutaneous tissues.

Oral localized amyloidosis.

This report describes two cases of oral localized amyloidosis (LA). In case 1, a 52-year-old man appeared with painful slightly, yellowish multiple nodules located on the dorsum of the tongue, of unknown duration. Incisional biopsy was performed, and the histopathologic analysis revealed a homogeneous, eosinophilic, and extracellular material. Congo red stain showed salmon pink coloration at light microscopy and apple-green birefringence at polarized light. In case 2, a 74-year-old man presented asymptomatic nodular lesions on the labial commissures with duration of several months. An excisional biopsy was performed in both lesions, and microscopically the specimen demonstrated the same histopathologic features of the case 1. Furthermore, amyloidosis with systemic involvement was excluded after investigations for both patients. Thus, the final diagnosis for both cases was LA. The patient 1 refused the surgical excision of the residual lesion, and in both cases, no signs of clinical and systemic progression were observed after 24 and 84 months of follow up. Although it is rare, LA should be considered in the differential diagnosis of multiple or single yellowish nodules on the oral cavity.

Oral Adult Rhabdomyoma.

This report describes a case of an adult rhabdomyoma (ARM) occurring in the oral cavity. A 47-year-old man was referred for the diagnosis of a painless, well-circumscribed, submucous nodule located on the floor of the mouth, measuring approximately 6.0 cm in length. Computed tomography revealed a well-defined, solid, and hypodense mass. A benign salivary gland or mesenchymal tumor were the main diagnostic hypotheses. Under local anesthesia, the patient underwent surgical excision. Microscopically, the tumor comprised large polygonal well-defined cells with abundant, eosinophilic granular cytoplasm with cross striations. No atypia or mitosis was observed. The cells were positive for muscle-specific actin, desmin, and sarcomeric alpha-actin. Based on these features, a diagnosis of ARM was established. No recurrence was observed after 48 months. Although rare, ARM should be considered in the differential diagnosis of oral submucosal nodules, especially those located on the floor of the mouth.

Chitosan/PCL nanoparticles can improve anti-neoplastic activity of 5-fluorouracil in head and neck cancer through autophagy activation.

Head and neck squamous cell carcinoma (HNSCC), a prevalent cancer worldwide, has a high incidence of loco-regional dissemination, frequent recurrence, and lower 5-year survival rates. Current gold standard treatments for advanced HNSCC rely primarily on radiotherapy and chemotherapy but with limited efficacy and significant side effects. In this study, we characterized a novel 5-fluorouracil (5-FU) carrier composed of chitosan solution (CS) and polycaprolactone (PCL) microparticles (MPs) in HNSCC preclinical models. The designed MPs were evaluated for their size, morphology, drug entrapment efficiency (EE%) and in vitro drug release profile. The anti-cancer activity of 5-FU-loaded particles was assessed in HNSCC human cell lines (CAL27 and HSC3) and in a preclinical mouse model (AT84) utilizing cell proliferation and survival, cell motility, and autophagy endpoints. The results demonstrated a 38.57 % in 5-FU entrapment efficiency associated with reduced 5-FU in vitro release up to 96 h post-exposure. Furthermore, CS-decorated PCL MPs were able to promote a significant inhibition of cancer cell proliferation based on the metabolic and colony formation assays, in comparison to controls. In contrast, CS-decorated PCL MPs did not influence the pharmacological efficacy of 5-FU to inhibit in vitro cancer cell migration. Last, cell protein analysis revealed a significant increase of autophagy and cell death evaluated by LC3-II expression and PARP1 cleavage, respectively. In summary, these results support the potential utility of CS-decorated PCL MPs as an effective 5-FU-delivery carrier to improve HNSCC therapeutic management.