Assessing bias in the causal role of HPV in oral cancer: A systematic review and meta-analysis.

OBJECTIVE: High-risk human papillomaviruses (HPV) are an established cause of oropharyngeal cancer. Their relationship with oral cancer remains unclear with detection ranging from 0% to 100%. HPV DNA detection or evidence of exposure alone is insufficient to conclude causality. This systematic review assesses the extent of bias in studies of HPV detection in cancers of the oral cavity. METHODS: PubMed, Ovid MEDLINE, EMBASE, and PsycInfo databases were searched for observational studies reporting the effect of HPV in oral cavity specific cancers. RESULTS: All 15 included studies presented HPV DNA detection or serum HPV-antibodies, none included mRNA E6/E7 analysis. Cases with oral cancer had 5.36 times (95% CI 3.29-8.72) higher odds of having HPV detected compared to controls. The odds of HPV detection were higher in cell-based (OR 6.93; 95% CI 0.82-58.55) and tissue samples (OR 5.28; 95% CI 3.41-8.18) than blood-based samples (OR 3.36; 95% CI 1.53-7.40). CONCLUSION: When cancer site is clearly differentiated between oropharynx and oral cavity, 12 studies showed strong association between HPV and oral cancer, but the available estimates lack internal validity due to inconsistent measurements, high confounding, and lack of gold standard testing. There is not high-quality evidence to conclude a causal relationship of HPV with oral cancer.

Eosinophils in Oral Disease: A Narrative Review.

The prevalence of diseases characterised by eosinophilia is on the rise, emphasising the importance of understanding the role of eosinophils in these conditions. Eosinophils are a subset of granulocytes that contribute to the body's defence against bacterial, viral, and parasitic infections, but they are also implicated in haemostatic processes, including immunoregulation and allergic reactions. They contain cytoplasmic granules which can be selectively mobilised and secrete specific proteins, including chemokines, cytokines, enzymes, extracellular matrix, and growth factors. There are multiple biological and emerging functions of these specialised immune cells, including cancer surveillance, tissue remodelling and development. Several oral diseases, including oral cancer, are associated with either tissue or blood eosinophilia; however, their exact mechanism of action in the pathogenesis of these diseases remains unclear. This review presents a comprehensive synopsis of the most recent literature for both clinicians and scientists in relation to eosinophils and oral diseases and reveals a significant knowledge gap in this area of research.

Confocal microscopy in oral cancer and oral potentially malignant disorders: A systematic review.

OBJECTIVE: To systematically identify and summarise current research on the utility of confocal microscopy in oral squamous cell carcinoma and oral epithelial dysplasia in oral potentially malignant disorders. METHODS: Databases Medline, Embase, Evidence-Based Medicine, and Web of Science were searched with articles screened and included if their primary objective was the use of a confocal microscope in diagnosis of oral cancer or epithelial dysplasia, in vivo or ex vivo. RESULTS AND DISCUSSION: Twenty-eight relevant studies were identified of which 21 studies included oral squamous cell carcinoma specimens. Fifteen studies included in vivo use. The studies included both qualitative and fluorescence confocal microscope and reflectance confocal microscope analysis along with quantitative analysis of carcinoma and dysplasia. Thirteen studies reported the predictive value of their confocal device in the diagnosis of dysplasia and carcinoma. The quantitative software-based studies show promise in objectifying the diagnostic process for identifying abnormalities within the microstructure of the oral mucosa. CONCLUSIONS: There was heterogeneity in the criteria for diagnosis of dysplasia and oral squamous cell carcinoma with experience levels of assessors impacting method efficacy. Both qualitative and quantitative confocal assessment methodologies have been explored, the latter highlighting the potential of future machine-augmented diagnostic precision.

Potential effects of anticoagulants in preclinical mice models of oral cancer: A systematic review.

Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer. There is mounting evidence to suggest that several components of the coagulation system directly affect carcinogenesis. Our recent in vitro studies demonstrated, for the first time, that various anticoagulants have anticancer effects on OSCC. They also showed the need for the immediate translation of these experimental conditions from bench to preclinical animal models. Here, we carried out a systematic review to summarise existing evidence on murine models built around the interactions between anticoagulants and oral cancer. Only one preclinical murine study was included in our systematic review, investigating the role of heparins in tumour pathophysiology. The paucity of evidence regarding the interactions between oral squamous cell carcinoma and anticoagulants emphasises the urgency with which further preclinical research should be conducted.

Transcriptional regulation of glucose transporters in human oral squamous cell carcinoma cells.

The increased glucose uptake observed in cancer cells is mediated by glucose transporters (GLUTs), a class of transmembrane proteins that facilitate the transport of glucose and other substrates across the plasma membrane. Despite the important role of glucose in the pathophysiology of oral squamous cell carcinoma (OSCC), there is very limited data regarding the expression of GLUTs in normal or malignant cells from the oral mucosa. We analysed the messenger RNA (mRNA) expression of all 14 GLUTs in two OSCC (H357/H400) and one non-malignant oral keratinocyte (OKF6) cell line using a quantitative polymerase chain reaction. GLUT expression was evaluated at baseline and after treatment with two specific GLUT inhibitors, namely, BAY876 (GLUT1) and WZB117 (GLUT1, GLUT3 and GLUT4). Here, we show that GLUT1, GLUT3, GLUT4, GLUT5, GLUT6, GLUT8, GLUT12 and GLUT13 transcripts were measurably expressed in all cell lines while GLUT2, GLUT7, GLUT9, GLUT11 and GLUT14 were not expressed. GLUT10 was only found in H357. In the presence of BAY876 and WZB117, OSCC cells exhibited significant alterations in the transcriptional profile of GLUTs. In particular, we observed distinct proliferation-dependent changes of mRNAs to GLUT1, GLUT3, GLUT4, GLUT5 and GLUT6 in response to selective GLUT inhibitors. In summary, we documented for the first time the expression of GLUT5, GLUT6 and GLUT12 in normal and malignant oral keratinocytes. Whilst regulation of GLUT transcripts was cell line and inhibitor specific, GLUT3 was consistently upregulated in actively proliferating OSCC cell lines, but not in OKF6, regardless of the inhibitor used, suggesting that modulation of this transporter may act as one of the primary compensation mechanisms for OSCC cells upon inhibition of glucose uptake.

Fixed drug eruptions - the common and novel culprits since 2000.

A fixed drug eruption (FDE) is a common cutaneous adverse drug reaction which occurs following administration of an offending drug. The aim of this review is to provide an update on the list of drugs causing FDE, with a focus on emerging drug culprits reported since the start of the century. Across published literature, triggers for FDE are widely varied. The most frequently implicated drugs include analgesics (nonsteroidal anti-inflammatory drugs [NSAIDs] and paracetamol) and antibiotics. Co-trimoxazole is perhaps the most well described single agent. Since the start of the century there have been over 200 drugs named in case reports on FDE. Newer, novel agents of note include cyclooxygenase-2 specific inhibitors, fluconazole, and phosphodiesterase 5 inhibitors. Other implicated drugs include vaccines, such as various SARS-CoV-2 vaccines. Drugs incriminated in FDE vary based on the geographical region studied and prescribing patterns at a given time. Newer drugs continue to enter the market and are playing an increasing role in the field of FDE. Awareness of rarer culprits and emerging novel agents can help identify a trigger, allowing for prompt withdrawal of the causative agent, preventing recurrence.

Inhibition of matrix metalloproteinase-2 modulates malignant behaviour of oral squamous cell carcinoma cells.

BACKGROUND: Matrix metalloproteinases (MMPs) play a crucial role in the malignant phenotype of cancer cells. In particular, active levels of MMP2 in cancer cells have been associated with invasion and metastasis through the degradation of basement membrane extracellular matrix proteins. However, little is known about the role of this potential biomarker in oral cancer. Our aim was to investigate the effect of MMP2 inhibition on OSCC activity in vitro, as well as to assess MMP2 dysregulation in oral cancer samples. METHODS: Human OSCC cell lines H357 and H400 were tested with the selective MMP2 inhibitor ARP101 and the MMP2 neutralising monoclonal antibody MA5-13590 to assess cell proliferation in vitro using MTS assay. Cell migration at 12/24 h was assessed using a Transwell migration assay. Cell invasion was assessed at 24 h using a Corning Matrigel invasion assay. MMP2 expression was assessed in 208 tissue samples (related to 60 OSCC cases and nine normal control) using tissue microarray (TMA) and further analysed via TCGA. RESULTS: Both ARP101 and MA5-13590 monoclonal antibody reduced cell proliferation in both the cell lines tested. Treatment with 4µg/mL of MMP2 monoclonal antibody showed a significant decrease in cell migration at 24 hours. The administration of ARP101 and monoclonal antibody to H357 and H400 cell lines induced a drastic reduction in cell invasion at 24 h compared to the control. In patients, TCGA analysis demonstrated that oral cancer tissues express significantly higher levels of MMP2 mRNA compared to normal oral tissues. Further, IHC analysis on TMA showed significant difference in MMP2 protein expression between low and high histopathological grade OSCC. CONCLUSIONS: We have demonstrated, for the first time, that MMP2 inhibition affects oral cancer cells ability to survive, migrate and invade in vitro. Differences between MMP2 expression in normal and malignant tissues varied. Further research on the role of MMP2 in OSCC and novel mechanisms to inhibit MMP2-dependent pathways should be encouraged.

Intraoral human herpes viruses detectable by PCR in majority of patients.

OBJECTIVES: To identify factors which influence the intraoral prevalence of human herpes viruses (HHVs) using mucosal swabs, saliva samples and qPCR analysis. METHODOLOGY: In this cross-sectional observational study, matched saliva and oral swabs were collected from a total of 115 subjects: 70 immunocompetent subjects with no mucosal abnormalities, 22 with mucosal abnormalities and 23 therapeutically immunocompromised individuals. Extracted DNA was analysed by multiplex qPCR for detection and quantification of HHVs 1-6. RESULTS: At least one human herpes virus was detected in 77.1% of immunocompetent individuals with no mucosal abnormalities, with EBV the most commonly detected at 61.4%. HHV-6 was detected in 17.1%, HSV-1 in 4.3% and CMV in 1.1%. Detection was higher in saliva than in oral swabs. There was no detection of HSV-2 or VZV. Neither presence of oral mucosal abnormality nor therapeutic immunocompromise was related to increased detection of human herpes virus. CONCLUSION: Commensal detection rates of EBV are high, and caution in clinical correlation of positive detection is warranted. Commensal CMV rates are low, and detection is likely to be clinically relevant. This study presents a comprehensive commensal detection rate of HHVs 1-6 by qPCR in saliva and swabs.

Comparison of the EUROIMMUN Dermatology Profile ELISA to the novel BIOCHIP Mosaic 7 for the diagnosis of immunobullous skin disease.

BACKGROUND: The BIOCHIP is an indirect immunofluorescence diagnostic investigation which identifies multiple autoantibodies with a mosaic panel of target antigen-specific substrates in a single incubation field. The EUROIMMUN Dermatology Profile ELISA allows simultaneous investigation of the six most important autoantibodies in bullous autoimmune dermatoses. Evaluation of the BIOCHIP Mosaic 7, compared to that of the EUROIMMUN Dermatology Profile ELISA, when used as a diagnostic investigation in pemphigus and pemphigoid, was undertaken in an Australian cohort. METHODS: The serum of 27 patients was analysed including patients with pemphigus vulgaris (n = 10), pemphigus foliaceous (n = 4), bullous pemphigoid (n = 8), mucous membrane pemphigoid (n = 3) and negative controls (n = 2). Results of the BIOCHIP were compared with the EUROIMMUN Dermatology Profile ELISA, as well as with histology, direct immunofluorescence and indirect immunofluorescence. RESULTS: In pemphigus vulgaris, sensitivity & specificity for the BIOCHIP Mosaic 7 were 100% and 94.1%, comparable to that of the EUROIMMUN Dermatology Profile ELISA with 80% sensitivity and 100% specificity. In bullous pemphigoid, sensitivity of the BIOCHIP was 87.5% and sensitivity of the EUROIMMUN Dermatology ELISA profile was 75%, whilst specificities for both diagnostic methods were 100% in our limited cohort. There was substantial or almost perfect concordance between the BIOCHIP Mosaic 7 and EUROIMMUN Dermatology Profile ELISA for pemphigus vulgaris and bullous pemphigoid. CONCLUSION: The BIOCHIP Mosaic 7 is a rapid, reliable diagnostic investigation in pemphigus and bullous pemphigoid. Results indicate it is comparable to the EUROIMMUN Dermatology Profile ELISA, whilst also providing additional testing with salt split skin, on one field.

Group pain education is as effective as individual education in patients with chronic temporomandibular disorders.

BACKGROUND: Temporomandibular disorders (TMD) are recognised as the most common chronic orofacial pain condition, with prevalence figures ranging from 3% to 12%. Patients referred to tertiary orofacial pain clinics for the management of TMD often experience delays in receiving treatment. The objective of the present study was to assess a group treatment programme to deliver effective earlier intervention for patients with chronic TMD. METHODS: Forty-two patients with TMD seen at the Oral Medicine Clinic, Royal Dental Hospital of Melbourne, were administered baseline validated pain questionnaires: the Graded Chronic Pain Scale and Pain Catastrophising Scale. Twenty patients subsequently received education about basic neurophysiology of pain, TMD and relaxation techniques in either a group setting or in a one-on-one session and were followed longitudinally. Administration of pain questionnaires was repeated at 4-6 weeks post-intervention. RESULTS: No evidence of difference in levels of anxiety, somatic symptoms or catastrophising was found between patients who received either group or individual intervention. Both were effective at reducing pain intensity and levels of disability. Individual intervention resulted in a greater reduction in rumination. CONCLUSION: Patients with TMD can receive effective reduction of TMD-related pain and catastrophising from either group or individual education regarding neurophysiology of pain, TMD and relaxation techniques. Group education should accelerate time to commencement of care in large referral-based settings.

Molecular diagnostics in oral cancer and oral potentially malignant disorders-A clinician's guide.

Current risk stratification of individuals for the development of oral squamous cell carcinoma (OSCC), including those with oral potentially malignant disorders (OPMD), remains based on clinical detection of visibly abnormal mucosa and tissue biopsy with histological assessment for the presence of OSCC or oral epithelial dysplasia (OED). In OPMD, the presence of OED remains the only prognostic tool used in standard care for the development of future OSCC, despite its ample limitations. There is assured potential that the analysis of the genome, transcripts and proteome can provide insight into what is occurring at a cellular level preceding the appearance of clinically observable change. The landscape of the role of the genome and its transcriptome on the development of OSCC and relationships with OPMDs are immense with exploration occurring on several fronts. For clinicians involved in the diagnosis and care of patients with OSCC and OPMD, understanding of commonly used molecular diagnostic techniques is imperative to gain useful insight from the expanding literature investigating the development of OSCC and the relationship with the clinical presentations which encompass OPMDs. Here we present an introduction to molecular diagnostic methods used in the study of OSCC and OPMD.

Extracellular Vesicles in Oral Squamous Cell Carcinoma and Oral Potentially Malignant Disorders: A Systematic Review.

Extracellular vesicles (EVs) are secreted from most cell types and utilized in a complex network of near and distant cell-to-cell communication. Insight into this complex nanoscopic interaction in the development, progression and treatment of oral squamous cell carcinoma (OSCC) and precancerous oral mucosal disorders, termed oral potentially malignant disorders (OPMDs), remains of interest. In this review, we comprehensively present the current state of knowledge of EVs in OSCC and OPMDs. A systematic literature search strategy was developed and updated to December 17, 2019. Fifty-five articles were identified addressing EVs in OSCC and OPMDs with all but two articles published from 2015, highlighting the novelty of this research area. Themes included the impact of OSCC-derived EVs on phenotypic changes, lymph-angiogenesis, stromal immune response, mechanisms of therapeutic resistance as well as utility of EVs for drug delivery in OSCC and OPMD. Interest and progress of knowledge of EVs in OSCC and OPMD has been expanding on several fronts. The oral cavity presents a unique and accessible microenvironment for nanoparticle study that could present important models for other solid tumours.

The protective effects of Kava (Piper Methysticum) constituents in cancers: A systematic review.

BACKGROUND: Kava is a beverage made from the ground roots of the plant Piper Methysticum and has long-held a significant place within Pacific island communities. Active compounds were extracted from kava, and secondary metabolites include kavalactones, chalcones, cinnamic acid derivatives and flavanones. It is thought that components of kava may exert an antiproliferative effect through cell cycle arrest and promotion of apoptosis. METHODS: We conducted a systematic review to summarize available evidence of the anticancer effects of kava components and investigate their potential use for oral squamous cell carcinoma (OSCC) treatment. Eligible studies were identified through a comprehensive search of OVID EMBASE, OVID MEDLINE and Web of Science, as at April 2018. RESULTS: Of 39 papers that met the inclusion criteria, 32 included in vitro models and 13 included animal studies. A total of 26 different cancers were assessed with 32 studies solely assessing epithelial cancers, 6 mesenchymal cancers and 1 study including both. There was only one report assessing an OSCC cell line. Antiproliferative properties were demonstrated in 32 out of 39 papers. The most researched constituent of kava was flavokavain B followed by flavokavain A. Both were associated with increased expression of pro-apoptotic proteins and decreased expression of anti-apoptotic proteins. Further, they were associated with a dose-dependent reduction of angiogenesis. CONCLUSION: There was heterogeneity of study models and methods of investigation across the studies identified. Components of kava appear to present an area of interest with chemotherapeutic potential in cancer prevention and treatment, particularly for epithelial neoplasms. To date, there is a paucity of literature of the utility of kava components in the prevention and treatment of oral squamous cell carcinoma.

World Workshop on Oral Medicine VII: Clinical evidence of differential expression of lncRNAs in oral squamous cell carcinoma: A scoping review.

BACKGROUND: Long non-coding RNAs (lncRNAs) have important roles in regulating gene expression pertaining to cell proliferation, survival, migration and genomic stability. Dysregulated expression of lncRNAs is implicated in cancer initiation, progression and metastasis. OBJECTIVES: To explore, map and summarize the extent of evidence from clinical studies investigating the differential expression of lncRNAs in oral/tongue squamous cell carcinoma. METHODS: PubMed, Scopus and Web of Science were used as search engines. Clinical, full-length, English language studies were included. PRISMA-ScR protocol was used to evaluate and present results. The present scoping review summarizes relationships of the differential expression of lncRNAs with the presence of tumour and with clinicopathological features including survival. RESULTS: Almost half of the investigated transcripts have been explored in more than one study, yet not always with consistent results. The collected data were also compared to the limited studies investigating oral epithelial dysplasia. Data are not easily comparable, first because of different methods used to define what differential expression is, and second because only a limited number of studies performed multivariate analyses to identify clinicopathological features associated with the differentially expressed lncRNAs. CONCLUSIONS: Standard methods and more appropriate data analyses are needed in order to achieve reliable results from future studies.

Applying Machine Learning for Enhanced MicroRNA Analysis: A Companion Risk Tool for Oral Squamous Cell Carcinoma in Standard Care Incisional Biopsy.

Machine learning analyses within the realm of oral cancer outcomes are relatively underexplored compared to other cancer types. This study aimed to assess the performance of machine learning algorithms in identifying oral cancer patients, utilizing microRNA expression data. In this study, we implemented this approach using a panel of oral cancer-associated microRNAs sourced from standard incisional biopsy specimens to identify cases of oral squamous cell carcinomas (OSCC). For the model development process, we used a dataset comprising 30 OSCC and 30 histologically normal epithelium (HNE) cases. We initially trained a logistic regression prediction model using 70 percent of the dataset, while reserving the remaining 30 percent for testing. Subsequently, the model underwent hyperparameter tuning resulting in enhanced performance metrics. The hyperparameter-tuned model exhibited high accuracy (0.894) and ROC AUC (0.898) in predicting OSCC. Testing the model on cases of potentially malignant disorders (OPMDs) revealed that leukoplakia with mild dysplasia was predicted as having a high risk of progressing to OSCC, emphasizing machine learning's advantage over histopathology in detecting early molecular changes. These findings underscore the necessity for further refinement, incorporating a broader set of variables to enhance the model's predictive capabilities in assessing the risk of oral potentially malignant disorders.

Evaluating global research trends in special needs dentistry: A systematic bibliometrix analysis.

OBJECTIVES: Special needs dentistry (SND) is a vast and fragmented field of study. This comprehensive bibliometric analysis aimed to evaluate the scope of SND, including the existing knowledge base, distribution structure, quantitative relationships, and research trends. MATERIAL AND METHODS: A systematic search was conducted on March 10, 2022, using the Web of Science Core Collection database, covering the period from 1985 to 2021, focusing on studies reporting on special needs populations in a dentally relevant context. Records were title-screened and analyzed for key bibliometric indicators. RESULTS: Among 48,374 articles, 13,869 underwent bibliometric analysis. Peak SND research occurred during 1985-1997. United States led in productivity, trailed by Brazil and Japan. University of Sao Paulo excelled in Brazil, University of Washington and University of North Carolina in the United States. The Journal of Dental Research was the most productive source of research and also had the highest number of citations, followed by Community Dentistry and Oral Epidemiology. Keyword analysis revealed that "elderly", "caries", and "epidemiology" were the most commonly used author keywords. CONCLUSIONS: This study represents the first bibliometric analysis of SND literature. It emphasizes the need for increased collaboration between institutions and authors. Furthermore, it suggests focusing on research input from non-dental disciplines and populations with rarer intellectual or developmental conditions.

The global distribution of special needs dentistry across dental school curricula.

INTRODUCTION: Special needs dentistry (SND) is an emerging dental specialty, with ongoing developments in education and clinical practice focused towards the tailored management of individuals with special needs (SN). Patients with SN have a higher prevalence of oral diseases and unmet dental needs compared to the general population. Although inadequate training and experience in managing patients with SN has been highlighted as a significant barrier to accessing care, there is limited data about the extent of SND teaching at the entry-to-practice or higher levels. METHODS: This work is the first to map SND curricula globally, across 180 countries and 1265 dental schools. RESULTS: Although 74.62% of dental schools were found in developing economies, the distribution of programs that reported SND in their courses was highly skewed towards developed countries. In terms of advanced degrees, beyond basic entry-to-practice training, the USA delivered 60% of the SND programs, followed by Canada (15.56%), UK (13.33%), and Australia (8.89%). The term SND appeared in 33.95% of entry-to-practice level program curricula and was less commonly used in transitioning economies. Only 112 SND-specialized practitioners enter the workforce globally each year from developed economies, and all but three advanced degrees are found in G7 countries. CONCLUSION: By exploring the impact of economic status on its distribution, this paper highlighted the lack of SND representation in dental curricula, especially amongst programs in transitioning or developing economies. Education of both general dentists and specialists is critical as a collaborative effort is needed to manage the growing population of patients with SN.