Potentially carcinogenic effects of hydrogen peroxide for tooth bleaching on the oral mucosa: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Little is known about the extent to which hydrogen peroxide as used for tooth bleaching could be carcinogenic to the oral mucosa.

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate whether hydrogen peroxide as used for tooth bleaching has carcinogenic effects on the oral mucosa.

MATERIAL AND METHODS

PubMed, Web of Science, Scopus, and Embase electronic databases were searched. Studies evaluating different outcomes potentially related to the carcinogenic effects of hydrogen peroxide for tooth bleaching on the oral mucosa were included. Risk of bias was assessed by the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE), Risk Of Bias in Non-randomized Studies of Interventions (ROBINS-I), or Risk of Bias 2 (RoB 2) tools. The strength of the evidence was assessed by using the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) protocol. The quantitative analysis was performed with means, standard deviations, and 95% confidence intervals (CIs). Heterogeneity was analyzed by using I-squared statistics.

RESULTS

Thirteen articles comprising 5 animal and 8 clinical studies met the inclusion criteria. Three of the 5 animal studies associated the bleaching agents with a carcinogen and demonstrated an enhancement of the carcinogenic effect, but probably with the bleaching agent acting only as a promoter. Five clinical studies concluded that the bleaching agents did not cause mutagenic stress on the oral mucosa by using the micronucleus test. The meta-analysis demonstrated that the frequency of micronuclei did not differ significantly between baseline and 30 days after bleaching (mean difference: 0.48; 95% CI, -1.49, 2.46; P=.63).

CONCLUSIONS

This systematic review indicated that hydrogen peroxide does not appear to have carcinogenic effects on the oral mucosa.

Oral squamous cell carcinoma cancer stem cells have different drug sensitive to pharmacological NFκB and histone deacetylation inhibition

Despite many progresses in the development of new systemic therapies for oral squamous cell carcinoma (OSCC), the five-year survival rate of OSCC is low. The traditional chemotherapies approach (cisplatin - CDDP) shows some limitations like drug toxicity, limited efficacy, and drug resistance. Promising studies suggested OSCC cancer stem cells (CSC) presented resistance to CDDP. We have previously studied many targets, and we extensively showed the efficacy of the NFκB signaling and the role of histones acetylation, on different malignant tumors, including adenoid cystic carcinoma and mucoepidermoid carcinoma, but until then the effects of the NFkB inhibitor and histone deacetylase (HDAC) inhibitor on the biology of OSCC were not evaluated. Here we assessed the pharmacological inhibitor of NFκB emetine and HDAC inhibitor SAHA on the behavior of CSC derived from OSCC. Our data suggested that CDDP administration resulted in reduced viability of bulk OSCC cells and increased CSC. A single and isolated shot of emetine and SAHA were able to disrupt CSC by inhibiting the NFκB pathway and increasing the histone acetylation levels, respectively. Further, the combined administration of emetine and SAHA presented the same CSC disruption as seen in emetine alone.

Impact of photobiomodulation for prevention of oral mucositis on the quality of life of patients with head and neck cancer: a systematic review

The aim of this study was to perform a systematic review to evaluate the impact of photobiomodulation therapy (PBMT) for the prevention of oral mucositis (OM) on the quality of life (QoL) of patients with head and neck cancer (HNC) undergoing radiation therapy. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The search strategy was performed in five electronic databases (Cochrane, Embase, PubMed, Scopus, and Web of Science). The included studies assessed the QoL of patients undergoing radiation therapy (RT) for HNC and undergoing PBMT for the management of OM. Seven articles met the eligibility criteria. Data extraction was performed in the selected studies including the PBMT parameters (active medium, application procedure, wavelength, fluence, power, irradiance, irradiation time, spot size, energy per point, schedule of irradiation, and total energy). The included studies were qualitatively analyzed, and descriptive analyses were performed. Also, summary results were evaluated for group comparison analysis. All included studies confirmed a decrease in the QoL of the patients that developed OM throughout the RT progress when compared to baseline. Of the informed cases, most of the patients who received PBMT showed grades 1 and 2 OM, while the control group showed more individuals with severe forms of OM (grades 3 and 4). In this sense, patients submitted to PBMT reported better QoL at the end of the treatment compared with the control group. PBMT used for the management of OM preserves the QoL of patients with head and neck cancer.

Virtual learning object about oral ulcerative lesions: controlled educational intervention study

The aim of this study was to develop a virtual learning object (VLO) to teach undergraduate dental students about the diagnostic and therapeutic approaches to oral ulcerative lesions. The VLO was developed with information on the diagnostic process, lesion classification, and clinical-surgical management of oral ulcerative lesions. The VLO content was initially validated by a group of specialists. Learning was evaluated in a sample of 58 undergraduate dental students, divided into control group (conventional theoretical class, n = 29) and intervention group (interaction with VLO, n = 29). All students answered a pre-test and post-test questionnaire. The VLO group also answered a specific questionnaire on the evaluation of the VLO. Both quantitative and qualitative descriptive analyses were performed. The validation showed that professors and students considered the VLO adequate. The use of the VLO was recommended by 100% of professors and 86.6% of students. In the intervention group, the results showed a significantly higher number of correct answers in the post-test (p < 0.01). In conclusion, the VLO proved to be a useful tool for teaching oral medicine, contributing significantly to the knowledge of ulcerated lesions in the mouth.

Oral and maxillofacial tuberculosis: A systematic review

OBJECTIVES

This study aimed to analyze the demographic, clinical, histopathological, diagnosis, treatment, and follow-up data on the occurrence of oral and maxillofacial tuberculosis (OMTB).

METHODS

Electronic searches without publication date restrictions were undertaken in four databases. Case reports and case series describing the occurrence of OMTB were included. Critical evaluation of studies was done using the Joanna Briggs Institute - University of Adelaide tool for case reports or case series.

RESULTS

A total of 217 studies were included in the qualitative synthesis, for a total of 301 cases of OMTB. Of these patients, 192 (63.7%) were male, with an average age of 39.6 ± 19.8 (15 months to 81 years). The tongue (n = 80/26.6%) represented the most common affected site, followed by the mandible (n = 43/14.3%). The clinical presentation consisted mainly of a painful ulcerated lesion (n = 156/56.5%). Histopathological analysis showed a granulomatous inflammation in most cases (n = 156/63.1%). The main diagnostic methods used were sputum test (n = 53/26.8%), culture (n = 49/24.7%) and purified protein derivative (PPD), or Mantoux test (n = 49/24.7%). Antituberculosis therapy was used in 244 cases (100.0%) and 5.2% of patients died.

CONCLUSIONS

This systematic review provided clinical, demographic data and information about diagnostic methods of OMTB lesions and served as an important guide to assist health professionals in the early diagnosis of these lesions.

Synchronous odontogenic tumors: A systematic review

This systematic review aimed to incorporate published information about synchronous odontogenic tumors (SOTs) with an analysis of the demographic and clinical characteristics from the cases published in the literature. Case reports and case series of SOT were searched in PubMed, Web of Science, Scopus, and EMBASE. A descriptive statistical analysis was performed. Twenty-eight studies comprising 30 cases of SOTs were included. Considering all cases published, SOTs mostly occurred simultaneously in the maxilla and mandible (n = 19/63.3%). Lesions were bifocal in 13 (43.3% of all the 30 cases) and multifocal in 17 cases (56.7% of all the 30 cases). All SOTs available in the literature presented the same type of lesion, and two of them also involved another different SOT (n = 2/6.7% of all the 30 cases). Out of all published cases, the most frequent SOTs in the literature were odontomas (n = 10/33.3% of all the 30 cases), squamous odontogenic tumors (OTs) (n = 8/26.7% of all the 30 cases), calcifying epithelial OTs (n = 8/26.7% of all the 30 cases), and adenomatoid OTs (n = 2/6.7% of all the 30 cases). Considering all SOTs cases included, the overall recurrence was 13.3%. Inside a subgroup of the lesion, synchronous calcifying epithelial OT presented the highest (25%). Five cases (16.7% of all the 30 cases) had a previously associated syndrome, with two cases of Schimmelpenning syndrome being reported. Among published SOTs, odontomas were the most common. All SOTs available in the scientific literature showed the same type of OT and mainly affected both jaws simultaneously. Only a few of these cases were associated with a syndrome.

Ewing's sarcoma of the head and neck: A systematic review

OBJECTIVE

The aim of the present study was to conduct a systematic review of head and neck Ewing sarcoma (ES) concerning patients' demographic and clinical features, histopathological findings, treatment, follow-up, and survival rate.

MATERIALS AND METHODS

An electronic search was undertaken in four databases. Articles describing case reports or case series were included. Outcomes were evaluated by the Kaplan-Meier method along with Cox regression.

RESULTS

The search yielded 186 studies describing 227 ES cases. The mean age was 22.7 years, and males were slightly more affected. Interestingly, more than half the cases were diagnosed up to 20 years. The respiratory tract was the most reported site, followed by the jawbones. Clinically, symptomatic swelling or nodules were described, with a mean duration of 4 months. Management involved multimodal treatment regimens. Local recurrence, lymph node and distant metastasis were observed in 10.7%, 12.6%, and 20.3% of cases, respectively. Statistical analysis revealed that older patients with distant metastasis had a lower overall survival rate (p < 0.05).

CONCLUSION

This study provides an overall view of head and neck ES that can assist oral and maxillofacial pathologists with the diagnosis and extend the knowledge of surgeons and oncologists about this condition.

Acinic cell carcinoma of the oral and maxillofacial region: an international multicenter study

The aim of this study was to describe the prevalence, clinicopathological, and prognostic features of acinic cell carcinoma (AciCC) of the oral and maxillofacial region. AciCC cases were retrospectively retrieved from 11 pathology centers of three different countries. Medical records were examined to extract demographic, clinical, pathologic, and follow-up information. A total of 75 cases were included. Females (65.33%) with a mean age of 45.51 years were mostly affected. The lesions usually presented as an asymptomatic (64.28%) nodule (95.66%) in the parotid gland (70.68%). The association of two histopathological patterns was the most common finding (48.93%) and the tumors presented mainly conventional histopathological grades (86.11%). Surgical treatment was performed in the majority of the cases (59.19%). Local recurrence was observed in 20% of the informed cases, regional metastasis in 30.43%, and distant metastasis in 12.50%. The statistical analysis showed that the cases with a solid histopathological pattern (p=0.01), high-grade transformation (p=0.008), recurrence (p=0.007), and regional metastasis (p=0.03) were associated with poor survival. In conclusion, high histopathological transformation, presence of nodal metastasis, and recurrence were prognostic factors for AciCC of the oral and maxillofacial region.

Impact of photobiomodulation in a patient-derived xenograft model of oral squamous cell carcinoma

BACKGROUND

Photobiomodulation therapy (PBMT) is an effective method for the prevention of oral mucositis. However, the effects of PBMT on oral squamous cell carcinoma (OSCC) have not yet been fully elucidated. This study aimed to evaluate the impact of PBMT in an OSCC-patient-derived xenograft (OSCC-PDX) model.

METHODS

BALB/c nude mice with OSCC-PDX models were divided into Control, without PBMT (n = 8); Immediate irradiation, PBMT since one week after tumor implantation (n = 6); and Late irradiation, PBMT after tumors reached 200 mm³ (n = 6). OSCC-PDX were daily irradiated (660 nm; 100 mW; 6 J/cm² ; 0,2 J/point) for 12 weeks. The tumors were collected and submitted to volumetric, histological, immunohistochemistry, and cell cycle analysis.

RESULTS

No significant differences in the volumetric measurements (p = 0.89) and in the histopathological grade (p > 0.05) were detected between the groups. The immunohistochemical analysis of Ki-67 (p = 0.9661); H3K9ac (p = 0.3794); and BMI1 (p = 0.5182), and the evaluation of the cell cycle phases (p > 0.05) by flow cytometry also did not demonstrate significant differences between the irradiated and non-irradiated groups.

CONCLUSION

In this study, PBMT did not impact the behavior of OSCC-PDX models. This is an important preclinical outcome regarding safety concerns of the use of PBMT in cancer patients.

Foreign body reactions related to orofacial esthetic fillers: A systematic review

The aim of this study was to systematically review the clinicopathological data regarding foreign body reactions (FBR) related to esthetic procedures in the orofacial region. Electronic searches were performed in six databases and in gray literature using PEO acronym for the review question. Case series and case reports describing FBR related to esthetic procedures in the orofacial region were included. The JBI Critical Appraisal Checklist-University of Adelaide tool was used for measuring the risk of bias. Eighty-six studies reporting 139 cases of FBR were identified. The mean age at diagnosis was 54.12 years (14-85 years), with most of the cases reported in America, North America (n = 42/30.70%) and Latin America (n = 33/23.60%), mainly occurring in women (n = 131/94.40%). Asymptomatic (n = 60/43.40%) nodules (n = 71/50.60%) were the main clinical characteristics. The lower lip represented the most affected anatomical location (n = 28/22.20%), followed by the upper lip (n = 27/21.60%). Surgical removal was the treatment of choice (n = 53/35.70%). Twelve different dermal fillers were reported in the study, and the microscopic characteristics of the cases varied according to the material used. The results based on case series and case reports showed that nodule and swelling were the main clinical characteristics of FBR related to orofacial esthetic fillers. The histological characteristics depended on the type of the filler material used.

Repurposing NFκB and HDAC inhibitors to individually target cancer stem cells and non-cancer stem cells from mucoepidermoid carcinomas

Drug resistance remains a major obstacle in the treatment of mucoepidermoid carcinomas (MEC) leading to tumor recurrence, disease progression, and metastasis. Emerging evidence suggests that drug resistance is mediated by the presence of a highly adaptative subpopulation of cancer cells known as cancer stem cells (CSC). We have previously reported that solid tumors use NFkB signaling as a chemotherapy-resistant mechanism. We have also shown that interfering with the epigenome of solid tumors is an effective strategy to control the population of CSC. Here, we sought to investigate the effects of the NFkB inhibitor emetine and the HDAC inhibitor SAHA on the biology of MEC CSC and assessed whether this combination therapy would favor the standard of care therapy comprised of the administration of Cisplatin (CDDP). Our findings suggested that the administration of low concentrations of emetine and SAHA is more effective in disrupting CSC in MEC, while the administration of emetine in combination with CDDP constitutes an effective therapy to target non-CSC MEC tumor cells.

Drug-based therapy for advanced adenoid cystic carcinoma: Current landscape and challenges based on an overview of registered clinical trials

Adenoid cystic carcinoma (ACC) has a significant patient-population in need of effective systemic therapy, as no drug is currently approved by the FDA for its management. We critically reviewed ACC-clinical trials (CT) registered on the ClinicalTrials.gov website using "ACC" under condition or disease. Trials specifically designed to test a drug-based therapy for ACC (n = 33) were analyzed with most being one-arm phase II trials enrolling advanced, recurrent/metastatic, incurable ACC cases. Site restriction, maximum ECOG status, and period of disease progression varied as inclusion criteria. Small-molecule inhibitors were those most commonly investigated with Apatinib, Axitinib and Lenvatinib showing the best results in association with rigid enrollment criteria. The overall median time to progression remains modest and more efforts are urgently needed in this field. CTs designed to test drugs that act on key pathways associated with ACC aggressiveness are being conducted and represent a promising pathway if efficacy is proved.

Global frequency and epidemiological profile of electronic cigarette users: a systematic review

OBJECTIVE

Electronic cigarette (e-cigarette) use is growing significantly worldwide, especially among young people. This product has been associated with renormalizing smoking and hindering quit attempts in smokers. Moreover, among nonsmokers, it can lead to subsequent cigarette smoking and nicotine dependence. The present study aimed to assess the epidemiological profile of e-cigarette users worldwide.

STUDY DESIGN

A systematic review was performed using 3 main electronic databases (Medline/PubMed, SCOPUS, and EMBASE). Studies were independently assessed by 2 reviewers based on established eligibility criteria. The risk of bias was assessed using the MAStARI critical appraisal instrument.

RESULTS

From 4,496 records, 43 were included. Among the 1,238,392 participants, 132,786 (10.72%) were e-cigarette users. The age range with the highest percentage of e-cigarette users was 18-24 years old, with 40,989 (30.86%) males, 34,875 (26.26%) females, and 33.6% being current cigarette smokers. The highest prevalence of users was 52.88% in Croatia and 49.62% in New Zealand. Other possible correlations were observed with e-cigarette use, such as a high level of education.

CONCLUSION

Overall, e-cigarette users tended to be male young adults with a higher level of education. The highest prevalence of use was found in Croatia. This systematic review provides valuable information to improve the development of appropriate intervention strategies targeting e-cigarette users for more accurate anti-smoking actions.

Association between perceived self-confidence and abilities to distinguish oral mucosal lesions amongst dental students

INTRODUCTION

Dentists usually refer to difficulties in performing the diagnosis of oral mucosal lesions. This may be attributed to limited access to theoretical lectures and practical training on this subject along the graduation course. The primary aim of this cross-sectional study was to verify if there is an association between the perception of time dedicated to lectures/training and oral diagnosis abilities in oral medicine. The secondary aim was to evaluate the association between self--confidence to perform oral mucosal lesions diagnosis and performance in a diagnostic abilities test.

MATERIALS AND METHODS

The sample comprised 36 final-year dental students of a South-Brazilian dental school. The participants answered a questionnaire on their perception of time dedicated to lectures on oral medicine along the course (sufficient or insufficient) and their self-confidence to diagnose oral mucosal lesions or oral cancer (yes or not). The students were also submitted to a diagnostic abilities test based on 30 clinical photos of oral lesions, which should be classified as benign, potentially malignant or malignant. Moreover, the participants had to inform their clinical impression for each case. Finally, the participants informed their decision making for the case (refer the patient to a specialist or not).

RESULTS

Students with higher self-confidence showed a higher percentage of correct answers on classification of the nature of lesions (81.1% vs. 68.5%, p = .03, teste t de Student) and on their clinical impression (66.3% vs. 41.7%, p < .01, Student's t-test). The perception of time dedicated to theoretical lectures on oral medicine as sufficient did not influence the students' diagnostic abilities (p > .05, Student's t-test) CONCLUSION: It may be concluded that self-confidence to diagnose oral lesions is associated with dental students' diagnostic abilities.

Distance learning course improves primary care dentists' diagnosis and self-efficacy in the management of oral lesions

Oral cancer represents a public health issue because of its high mortality rate, resulting mainly from diagnostic delays. Insufficient training in oral diagnosis is usually perceived by dentists. Distance learning could be used as an auxiliary tool to bridge that gap. This study evaluated the impact of a distance learning course on oral mucosal lesion diagnosis offered to public healthcare dentists. Participants of an online course answered a pretest/posttest comprising clinical images of 30 clinical cases. Participants were questioned about the diagnosis and informed their decision on the cases (referring the cases to a specialist or managing them themselves), as a parameter of perceived self-efficacy. A total of 442 dentists enrolled in the course. Their pass rate was 97%. Classification of the nature of the lesions, diagnostic hypotheses, sensitivity, and specificity improved by 13.4%, 10.0%, 13.4%, and 6.6%, respectively (p<0.01, Wilcoxon test). Regarding management, there was a 16.6% reduction in the intention to refer cases, while confidence in the diagnosis of benign lesions increased by 40%. A distance learning course may be useful in continuing education actions for primary care dentists, improving their diagnostic abilities and encouraging them in the management of oral lesions. Moreover, this strategy could contribute to disseminating knowledge to remote regions, particularly among primary health care professionals.

4-nitroquinoline-1-oxide (4NQO) induced oral carcinogenesis: A systematic literature review

OBJECTIVE

Based on a critical review of published studies, we aimed to develop a good practice guide for using 4-nitroquinoline-1-oxide (4NQO) as an inducer of oral carcinogenesis in Wistar rats.

DESIGN

A systematic search was performed on Medline Ovid, PubMed, Embase, Web of Science, and Scopus databases. The SYRCLE's risk of bias tool was used to assess the quality of the studies.

RESULTS

Thirty-five articles met the selection criteria; 22 (62.9%) of them administered 4NQO systemically in drinking water, with a mean concentration of 30.2 ppm (SD±15.9) and during a mean period of 20.8 (SD±7.8) weeks. The other 13 (37.1%) studies performed topical applications of 4NQO painting the oral mucosa of the animals three times a week (100%) with a mean period of administration of 16.8 (SD±7.0) weeks. Different 4NQO concentrations used for other periods achieved significant tumor development. Most studies didn't perform quantitative clinical analysis, and the histopathological diagnosis/grading criteria varied considerably.

CONCLUSIONS

A poor description of solution care, adverse effects, and the number of losses were observed, and the reporting of these features needs to be improved. Suggestions to guide the development of future research are provided.

Expression of DNMTs and H3K9ac in Ameloblastoma and Ameloblastic Carcinoma

Objectives: DNA methyltransferases (DNMTs) and the histone modification H3K9ac are epigenetic markers. This study aimed to describe the immunohistochemical expression of DNMT1, DNMT3A, DNMT3B, and H3K9ac in the dental follicle (DF), ameloblastoma (AME), and ameloblastic carcinoma (AC), correlating these expressions with the recurrence and aggressive behavior in ameloblastoma.

Study Design: Immunohistochemical reactions were performed in 10 human DFs, 38 ameloblastomas, and 6 AC samples. Another 59 ameloblastomas assembled in a tissue microarray were used to compare the immunoexpression with the clinical, radiographic, and histopathological characteristics and the presence of BRAFv600e mutation. Each slide was digitized as a high-resolution image and quantified by Aperio ScanScope Nuclear V9 software. All statistical analyzes were performed using GraphPad Prism statistical software.

Results: DNMT3B expression was higher in ameloblastomas than in the DFs, while the AC overexpressed all proteins. The ameloblastomas with BRAFv600e mutation, vestibular/lingual, or vestibular/palatine bone cortical disruption and maxilla involvement showed DNMT1 overexpression, while recurrent cases had high DNMT3B levels.

Conclusions: DNA methylation and histone modification might play a role in the development, clinical aggressiveness, and recurrence rates of ameloblastoma, such as the progression to AC. Further investigation about gene methylations in ameloblastomas is needed to better understand its relationship with aggressiveness and recurrence.

Oral and Maxillofacial Neuroendocrine Carcinoma: A Systematic Review

The aim of the present study was to integrate the available data published in the literature on oral and maxillofacial neuroendocrine carcinomas concerning the demographic, clinical and histopathological features of this condition. An electronic search with no publication date restriction was undertaken in April 2021 in four databases. Eligibility criteria included reports published in English having enough data to confirm a definite diagnosis, always showing a neuroendocrine marker. Cases originating in the oropharynx, including base of the tongue and tonsils, were excluded. Outcomes were evaluated by the Kaplan-Meier method along with Cox regression. Twenty-five articles (29 cases) from nine different countries were detected. Mean patient age was 56.3 (± 17.5) years, with a slight male predilection. Symptomatology was present in 72.2% of informed cases. Regarding clinical presentation, a non-ulcerated nodule located in the gingiva with a mean size of 3.4 (± 2.0) cm was most frequently reported. Concomitant metastasis was identified in seven individuals. Histopathologically, most neoplasms were of the small cell type, and immunohistochemistry for both epithelial and neuroendocrine differentiation was used in 65.5% cases. Radical surgery was the treatment of choice in almost all cases, with or without adjuvant therapy. Mean follow-up was 20.5 (± 21.2) months, and only four patients developed recurrences. Eleven (44.0%) individuals died due to the disease. Ulcerated lesions were a prognostic factor. This study provides knowledge that can assist surgeons, oncologists, and oral and maxillofacial pathologists with the diagnosis and management of neuroendocrine carcinomas. Our findings demonstrated that the long-term prognosis of this lesion continues to be poor.

Cephaeline is an inductor of histone H3 acetylation and inhibitor of mucoepidermoid carcinoma cancer stem cells

AIM

To evaluate the potential use of Cephaeline as a therapeutic strategy to manage mucoepidermoid carcinomas (MEC) of the salivary glands.

MATERIAL AND METHODS

UM-HMC-1, UM-HMC-2, and UM-HMC-3A MEC cell lines were used to establish the effects of Cephaeline over tumor viability determined by MTT assay. In vitro wound healing scratch assays were performed to address cellular migration while immunofluorescence staining for histone H3 lysine 9 (H3k9ac) was used to identify the acetylation status of tumor cells upon Cephaeline administration. The presence of cancer stem cells was evaluated by the identification of ALDH enzymatic activity by flow cytometry and through functional assays using in vitro tumorsphere formation.

RESULTS

A single administration of Cephaeline resulted in reduced viability of MEC cells along with the halt on tumor growth and cellular migration potential. Administration of Cephaeline resulted in chromatin histone acetylation as judged by the increased levels of H3K9ac and disruption of tumorspheres formation. Interestingly, ALDH levels were increased in UM-HMC-1 and UM-HMC-3A cell lines, while UM-HMC-2 showed a reduced enzymatic activity.

CONCLUSION

Cephaeline has shown anti-cancer properties in all MEC cell lines tested by regulating tumor cells' viability, migration, proliferation, and disrupting the ability of cancer cells to generate tumorspheres.

Defocused high-power diode laser accelerates skin repair in a murine model through REDOX state modulation and reepithelization and collagen deposition stimulation

Skin wounds represent a burden in healthcare. Our aim was to investigate for the first time the effects of defocused high-power diode laser (DHPL) on skin healing in an animal experimental model and compare it with gold standard low-level laser therapy. Male Wistar rats were divided into 5 groups: Negative control; Sham; 0.1 W laser (L0.1 W); DHPL Dual 1 W (DHPLD1 W); and DHPL Dual 2 W (DHPLD2 W). Rats were euthanized on days 3, 5, 10, 14 and 21. Clinical, morphological, PicroSirus, oxidative stress (MDA, SOD and GSH) and cytokines (IL-1β, IL-10 and TNF-α) analyses were performed. A faster clinical repair was observed in all laser groups at D10 and D14. DHPLD1 W exhibited lower inflammation and better reepithelization compared to other groups at D10. DHPL protocols modulated oxidative stress by decreasing MDA and increasing SOD and GSH. Collagen maturation was triggered by all protocols tested and L0.1 W modulated cytokines release (IL-1β and TNF-α) at D3. In conclusion, DHPL, especially DHPL1 W protocol, accelerated skin healing by triggering reepithelization and collagen maturation and modulating inflammation and oxidative stress.

Malignant peripheral nerve sheath tumour of the oral and maxillofacial region-A systematic review

To integrate the available data published on malignant peripheral nerve sheath tumours (MPNST) of the oral and maxillofacial region. Searches in Embase, PubMed, Web of Science and Scopus were conducted for the identification of case reports/case series in English language. The risk of bias was assessed using the Joanna Briggs Institute tool. Outcomes were evaluated by Cox regression and Kaplan-Meier methods. A total of 306 articles were retrieved, 50 of which reporting 57 MPNST were included. The lesion showed a predilection for the mandible (n = 18/31.57%) of middle-aged adults (~40.5 years) with a male/female ratio of 1.1:1. The individuals were mostly symptomatic with a mean evolution time of 9.6 months. Surgical removal plus adjuvant therapy (especially radiotherapy) was the main approach (51.86%). Recurrence was reported in 39.62% of cases. Nodal and distant metastases were identified in 28.26% and 26.66% of cases, respectively. The 2-year cumulative survival rate was 55%. Independent predictors of poor survival were the presence of neurofibromatosis type 1 (p = 0.04) and distant metastases (p = 0.004). The diagnosis of MPNST is challenging due to the variety of its clinical and histopathological presentations. Local aggressiveness and the potential for metastases are common outcomes of this neoplasm.

Mantle cell lymphoma, malt lymphoma, small lymphocytic lymphoma, and follicular lymphoma of the oral cavity: An update

BACKGROUND

Although uncommon, mature small B-cell lymphomas may arise in the oral/maxillofacial area and oral pathologists must be aware of the key characteristics of these neoplasms to perform an accurate diagnosis. In this manuscript, we attempted to integrate the currently available data on the clinicopathological features of follicular lymphoma (FL), mantle cell lymphoma (MCL), extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT-L), and chronic lymphocytic leukemia/ small lymphocytic lymphoma (CLL/SLL) affecting these anatomical regions.

METHODS

An updated descriptive literature review was carried out and a detailed electronic search was done in multiple databases to gather all cases affecting the oral/maxillofacial region and palatine tonsils.

RESULTS

We observed that MALT-L was the most frequently reported subtype, followed by FL, MCL, and CLL/SLL. The palate was affected in a high proportion of cases and the most usual clinical presentation was an asymptomatic swelling. MALT-L and CLL/SLL neoplastic cells were strongly associated with small salivary glands. FL showed no gender preference, while MCL and CLL/SLL were more prevalent in males and MALT-L in females. Overall, cases were more common in elderly individuals. Patients' treatment and outcome varied, with MCL being the most aggressive neoplasm with a dismal prognosis in comparison to FL and MALT-L.

CONCLUSION

Despite the poor documentation in many of the cases available, especially regarding the microscopic and molecular features of tumors, this review demonstrated that the oral mature small B-cell lymphomas investigated share similar clinical presentation, but carry different prognostic significance, demanding an accurate diagnosis.

Epigenetic modulation of the tumor microenvironment in head and neck cancer: Challenges and opportunities

Head and neck cancer is globally challenging due to the resistance to therapy and aggressive behavior leading to high rates of mortality. Recent findings show that the tumor microenvironment plays a role in the maintenance and progression of many solid tumors, including head and neck cancer. The mechanisms involved in the modulation and regulation of the tumor microenvironment remain poorly understood. Increasing evidence suggests that epigenetic events can modulate the crosstalk between neoplastic and non-neoplastic cells during tumor progression. In this review, we explore the current understanding of the involvement of epigenetic events in the modulation of the tumor microenvironment and its impact on head and neck cancer behavior. We also explore the latest therapeutic strategies that use epigenetic-modulating drugs to manage tumor growth and progression.

Risk factors associated with the development of oral mucositis in pediatric oncology patients: Systematic review and meta-analysis

OBJECTIVES

Oral mucositis (OM) is an acute toxicity related to cancer treatment. This systematic review aimed to identify potential risk factors associated with the development of OM in pediatric cancer patients.

METHODS

A search was performed in four electronic databases to identify studies that analyzed risk factors for OM in pediatric cancer patients.

RESULTS

Nineteen articles were included. The incidence of OM ranged from 20% to 80.4%. Chemotherapeutic agents were potential risk factors for OM in eight (42%) studies. Hematological, hepatic, and renal parameters were also considered in eight (42%) studies, while specific individual factors were reported in five (26.3%) studies. Baseline disease, oral microbiota, genetic profile, and biomarkers were reported in four (21.5%) studies each. Meta-analysis showed that groups submitted to high-risk chemotherapy for OM had a 2.79-fold increased risk of OM.

CONCLUSIONS

Identifying risk factors for OM is essential in order to allow individualized and early prevention treatment.

Clinicopathological analysis of oral and maxillofacial acinic cell carcinoma: A systematic review

BACKGROUND

The aim of the present systematic review was to analyze the available data regarding acinic cell carcinoma of the oral and maxillofacial region.

METHODS

A search strategy was performed using PubMed, Web of Science, Scopus, and Embase electronic databases.

RESULTS

Available data revealed a slight female preference (54.73%) and a mean age at diagnosis of 47.51 ± 19.85 years. The parotid glands (67.72%) were most frequently affected, and most cases were asymptomatic (69.54%). A microcystic histopathological pattern was reported in 21.56% of the cases, and the Periodic acid-Schiff was the staining method most frequently used, after the hematoxylin and eosin staining, in the tumors analyzed. The lesions were mainly treated by surgical removal (72.32%). Recurrence was reported in 81 cases (27.83%) and metastasis in 100 (42.91%). Statistical data analysis revealed that tumors located in major salivary glands and exhibiting high-grade histology were associated with local recurrence (P = .01). In addition, the patients older than 57 years, lesions with bone involvement, the high-grade tumors and the cases with a history of recurrence and metastasis were associated with a lower overall survival (P < .05).

CONCLUSION

By assembling all eligible cases in the literature, the present systematic review determined the most common clinicopathological profile of acinic cell carcinoma and the most relevant prognostic factors in a distinctly representative sample. The survey demonstrated the importance of considering the histopathological grading in order to better define the treatment for each case.

Prevalence and distribution of dental anomalies in a paediatric population based on panoramic radiographs analysis

AIM

To evaluate the frequency and distribution of dental anomalies (DA) in a paediatric population.

MATERIALS AND METHODS

Panoramic digital radiographs of children between 6 and 12 years old performed at a reference centre for radiographic exams were accessed. Two calibrated examiners evaluated the radiographs. The association between variables and outcomes was assessed using non-parametric tests. The significance level was set at 5%.

RESULTS

Five hundred and twelve individuals were included and 61.3% presented at least one DA. The mean age of patients with DA (9.35±1.60) was significantly higher compared to patients with no anomalies (7.90±1.58). Patients with supernumerary tooth, however, were significantly younger. The most frequent DA were permanent tooth radicular dilacerations (38.1%), permanent tooth agenesis (29.3%), supernumerary tooth (6.4%) and impacted tooth (6.4%). Anterior teeth and female patients were more affected by radicular dilacerations. Dental agenesis was more frequent in the third molars followed by the upper lateral incisor.

CONCLUSION

DA are quite frequent in the paediatric population and the most common DA observed herein could only be identified through imaging exams. The most appropriate timing to perform an investigation for the detection of dental anomalies appears to be between 9 and 10 years old.

Central odontogenic fibroma: an international multicentric study of 62 cases

OBJECTIVE

The aim of this study was to report the clinicopathologic features of 62 cases of central odontogenic fibroma (COdF).

STUDY DESIGN

Clinical and radiographic data were collected from the records of 13 oral pathology laboratories. All cases were microscopically reviewed, considering the current World Health Organization classification of tumors and were classified according to histopathologic features.

RESULTS

There were 43 females and 19 males (average age 33.9 years; range 8-63 years). Clinically, COdF lesions appeared as asymptomatic swellings, occurring similarly in the maxilla (n = 33) and the mandible (n = 29); 9 cases exhibited palatal depression. Imaging revealed well-defined, interradicular unilocular (n = 27), and multilocular (n = 12) radiolucencies, with displacement of contiguous teeth (55%) and root resorption (46.4%). Microscopically, classic features of epithelial-rich (n = 33), amyloid (n = 10), associated giant cell lesion (n = 7), ossifying (n = 6), epithelial-poor (n = 3), and granular cell (n = 3) variants were seen. Langerhans cells were highlighted by CD1a staining in 17 cases. Most patients underwent conservative surgical treatments, with 1 patient experiencing recurrence.

CONCLUSIONS

To the best of our knowledge, this study represents the largest clinicopathologic study of COdF. Most cases appeared as locally aggressive lesions located in tooth-bearing areas in middle-aged women. Inactive-appearing odontogenic epithelium is usually observed within a fibrous/fibromyxoid stroma, occasionally exhibiting amyloid deposits, multinucleated giant cells, or granular cells.

An audit of cytopathology in the oral and maxillofacial region: 18 years of experience

INTRODUCTION

The aim of this study was to perform an audit of oral and maxillofacial specimens submitted for cytological diagnosis to verify the importance of this complementary examination.

METHODS

A retrospective analysis of our institutional cytopathology database was performed over an 18-year period. Clinical information and cytological data were collected. Associations between independent variables and outcomes were assessed using the Pearson χ² test or Fisher's test, with a 5% significance level. When available, the histological diagnosis was compared with cytological diagnosis to identify the percentage of agreement and the specificity, sensitivity and accuracy of cytology in identifying malignant neoplasms.

RESULTS

A total of 1082 cases were identified, which included 65 different cytological diagnoses. Exfoliative cytology (EC) was performed in 312 cases (29.1%) and fine needle aspiration cytology (FNAC) in 770 cases (70.9%). EC was mainly employed to diagnose oral infectious diseases (P < 0.001) and FNAC to diagnose neoplasms, cystic, reactive and miscellaneous lesions (P < 0.001). Cell-block was performed in 555 FNAC cases (51.3%). Panoptic, Papanicolaou and haematoxylin-eosin staining were performed in FNAC and periodic acid-Schiff in EC (P < 0.001). In 211 cases (19.5%), the histological diagnosis was available and the percentage agreement with the cytological diagnosis was 41.2%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy to identify malignant neoplasms were 84.6%, 100%, 100%, 77.8% and 90.0%, respectively.

CONCLUSIONS

EC was mainly performed for diagnosis of infectious diseases and FNAC for diagnosis of salivary gland tumours, odontogenic lesions, reactive lesions and cervical metastasis.

The impact of photobiomodulation therapy on the biology and behavior of head and neck squamous cell carcinomas cell lines

Photobiomodulation therapy (PBMT) is an emerging therapeutic modality designed to prevent and treat chemotherapy-driven oral mucositis (OM). However, the response of tumor cells to the effects of PBMT remains poorly understood. Our study explores the effects of PBMT in head and neck squamous cell carcinoma (HNSCC) based on cellular proliferation, migration, and survival of tumor cells and its population of cancer stem cells (CSC). We explored the behavior of two HNSCC cell lines (HN6 and HN13) under two distinct conditions, a physiological growing condition (10% FBS), and under stress growing condition (2% FBS) prior to irradiation using diode laser (InGaAlP; MM Optics, São Carlos, SP, Brazil). Diode laser (660 nm) was applied with a power of 100 mW delivering a total energy per point of 0.24 J. MTT and wound healing test (scratch assay) were performed to evaluate, respectively, proliferation and migration of tumor cells. Clonogenic and spheres formation assays were also performed to evaluate the survival and percentage of CSC upon irradiation. Overall, we observed that PBMT does not exacerbate the behavior of HNSCC. We could only observe a decrease in cellular proliferation of one cell line (HN6) when cultured under nutritional stress conditions (p < .05). There were no significant differences between the control and the PBMT groups regarding cell migration, survival and the percentage of CSC. Collectively, our results suggest that in vitro administration of PBMT to HNSCC does not modify the behavior of tumor cells.

Factors associated with incomplete surgical margins in basal cell carcinoma of the head and neck

Introduction

Cutaneous basal cell carcinoma recurrence is associated with inadequate surgical margins. The frequency of and the factors associated with compromised or inadequate surgical margins in head and neck basal cell carcinoma varies.

Objective

The purpose of this study was to evaluate the clinical and pathological factors associated with inadequate surgical margins in head and neck basal cell carcinoma.

Methods

We developed a cross-sectional study comprising all patients who had undergone resection of head and neck basal cell carcinoma from January 2017 to December 2019. Data on age, sex, head and neck topography, histopathological findings, and staging were retrieved and compared. Each tumor was considered an individual case. Compromised and close margins were termed “inadequate” or “incomplete”. Variables that were significantly associated with the presence of incomplete margins were further assessed by logistic regression.

Results

In total, 605 tumors from 389 patients were included. Overall, sixteen cases (2.6%) were classified as compromised, 52 (8.5%) as close, and 537 (88.7%) as free margins. Presence of scleroderma (p = 0.005), higher Clark level (p < 0.001), aggressive variants (p < 0.001), invasion beyond the adipose tissue (p < 0.001), higher T stage (p < 0.001), perineural invasion (p = 0.002), primary site (p = 0.04), multifocality (p = 0.01), and tumor diameter (p = 0.02) showed association with inadequate margins. After Logist regression, multifocality, Clark level and depth of invasion were found to be independent risk factors for inadequate margins.

Conclusion

Gross clinical examination may be sufficient for determining low prevalence of inadequate surgical margins when treating head and neck basal cell carcinoma in highly experienced oncologic centers. Multifocality, Clark level and depth of invasion were found to be independent risk factors for incomplete margins.

Better outcome for parotid versus neck metastasis of head and neck cutaneous squamous cell carcinoma: a new report on reemerging data

INTRODUCTION

Regional metastases of cutaneous head and neck squamous cell carcinoma occur in approximately 5 % of cases, being the most important prognostic factor in survival, currently with no distinction between parotid and neck metastasis.

OBJECTIVE

The purpose of this study was to evaluate the prognostic features among patients with head and neck cutaneous squamous cell carcinoma exhibiting regional metastasis.

METHODS

A retrospective analysis of patients with cutaneous squamous cell carcinoma who underwent parotidectomy and/or neck dissection from 2011 to 2018 at a single institution tertiary center was performed. Patient demographics, clinical, surgical and pathological information, adjuvant treatments, and outcome at last follow-up were collected. Outcomes included disease recurrence and death due to the disease. Prognostic value of clinic pathological features associated with disease-specific survival was obtained.

RESULTS

Thirty-eight cases of head and neck cutaneous squamous cell carcinoma with parotid and/or neck metastasis were identified. Overall, 18 (47.3 %) patients showed parotid metastasis alone, 12 (31.5 %) exhibited neck metastasis alone and 8 (21.0 %) had both. A primary tumor in the parotid zone (Hazard Ratio ‒ HR = 5.53; p = 0.02) was associated with improved disease-specific survival. Poorer disease-specific survival was observed in patients with higher primary tumor diameter (HR = 1.54; p = 0.002), higher depth of invasion (HR = 2.89; p = 0.02), invasion beyond the subcutaneous fat (HR = 5.05; p = 0.002), neck metastasis at first presentation (HR = 8.74; p < 0.001), number of positive lymph nodes (HR = 1.25; p = 0.004), and higher TNM stages (HR = 7.13; p = 0.009). Patients presenting with isolated parotid metastasis during all follow-ups had better disease-specific survival than those with neck metastasis or both (HR = 3.12; p = 0.02).

CONCLUSION

Head and neck cutaneous squamous cell carcinoma with parotid lymph node metastasis demonstrated better outcomes than cases with neck metastasis.

Histones Acetylation and Cancer Stem Cells (CSCs)

Chromatin decondensation is a key mechanism that guarantees gene transcription and repair of the genome, regulated mainly by the acetylation of histones. Emerging evidence has pointed out to histones as a new controlling mechanism of stem cell maintenance and fate. In this chapter, we will focus on the methods used to enrich tumor cell lines for cancer stem cells, and in the methods to identify the status of the histone acetylation in cancer cells and stem cells using immunofluorescence, invasion, and adhesion assays and identification of nuclear size.

Uncovering the role of brain-derived neurotrophic factor/tyrosine kinase receptor B signaling in head and neck malignancies

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family of growth factors that was first known as responsible for sustain the growth, function, and plasticity of neural cells. BDNF exerts its effects by binding to the tyrosine kinase receptor B (TrkB). The BDNF/TrkB axis has been reported to be overexpressed in several neurogenic and non-neurogenic tumors. Its higher expression was associated with a poor prognosis to patients affected by different human malignancies, tumor growth, invasion, and metastasis; epithelial-mesenchymal transition and resistance to chemotherapy. BDNF/TrkB represent promising targets to the development of novel anticancer therapies. Some clinical trials are currently evaluating the efficacy of Trk protein-target drugs in different types of solid tumors. To date, few groups have evaluated the DNF/TrkB pathway in head and neck malignancies. The aims of this study were to review the literature concerning the role of BDNF/TrkB activation in head and neck squamous cell carcinoma and malignant salivary gland tumors and to discuss future perspectives of BDNF/TrkB-target therapy.

Bryne's grading system predicts poor disease-specific survival of oral squamous cell carcinoma: a comparative study among different histologic grading systems

OBJECTIVES

The aim of this study was to access the prognostic value of 4 histopathologic grading systems of oral squamous cell carcinoma (OSCC): The World Health Organization (WHO), Anneroth, Bryne (1989), and Bryne (1992).

STUDY DESIGN

Eighty-five cases of OSCC diagnosed between 1996 and 2010 at the Clinics Hospital of Porto Alegre (Porto Alegre, Brazil) were included. Slides stained with hematoxylin and eosin were obtained, and a histologic grade was assigned on the basis of the consensus of 3 expert oral pathologists, who were blinded to the clinicopathologic factors. Each system was correlated with proliferative labeling index, accessed through Ki67 immunostaining, clinicopathologic factors, patient outcome (alive or deceased), and survival time.

RESULTS

The increase in Bryne (1992) histologic grades was accompanied by an increase in proliferative labeling index. Moreover, this system was the only one associated with patient outcome (P = .01) and survival. Bryne (1992) grading system grade III tumors were associated with poor disease-specific survival according to univariate and multivariate cox regression analyses and the log-rank test (P < .05). The other systems evaluated presented no association with patients' outcome or survival.

CONCLUSIONS

The Bryne (1992) grading system is more effective in predicting survival in OSCC compared with the systems proposed by the WHO, Anneroth, or Bryne (1989).