Advances in optical adjunctive AIDS for visualisation and detection of oral malignant and potentially malignant lesions

AI-Assisted Screening of Oral Potentially Malignant Disorders Using Smartphone-Based Photographic Images

The prevalence of oral potentially malignant disorders (OPMDs) and oral cancer is surging in low- and middle-income countries. A lack of resources for population screening in remote locations delays the detection of these lesions in the early stages and contributes to higher mortality and a poor quality of life. Digital imaging and artificial intelligence (AI) are promising tools for cancer screening. This study aimed to evaluate the utility of AI-based techniques for detecting OPMDs in the Indian population using photographic images of oral cavities captured using a smartphone. A dataset comprising 1120 suspicious and 1058 non-suspicious oral cavity photographic images taken by trained front-line healthcare workers (FHWs) was used for evaluating the performance of different deep learning models based on convolution (DenseNets) and Transformer (Swin) architectures. The best-performing model was also tested on an additional independent test set comprising 440 photographic images taken by untrained FHWs (set I). DenseNet201 and Swin Transformer (base) models show high classification performance with an F1-score of 0.84 (CI 0.79-0.89) and 0.83 (CI 0.78-0.88) on the internal test set, respectively. However, the performance of models decreases on test set I, which has considerable variation in the image quality, with the best F1-score of 0.73 (CI 0.67-0.78) obtained using DenseNet201. The proposed AI model has the potential to identify suspicious and non-suspicious oral lesions using photographic images. This simplified image-based AI solution can assist in screening, early detection, and prompt referral for OPMDs.

Characteristics of Clinically Classified Oral Lichen Planus in Optical Coherence Tomography: A Descriptive Case-Series Study

Malignant transformation of oral lichen planus (OLP) into oral squamous cell carcinoma is considered as one of the most serious complications of OLP. For the early detection of oral cancer in OLP follow-up, accurate localization of the OLP center is still difficult but often required for confirmatory biopsy with histopathological examination. Optical coherence tomography (OCT) offers the potential for more reliable biopsy sampling in the oral cavity as it is capable of non-invasively imaging the degenerated oral layer structure. In this case-series study with 15 patients, features of clinically classified forms of OLP in OCT cross-sections were registered and correlated with available histologic sections. Besides patients with reticular, atrophic, erosive and plaque-like OLP, two patients with leukoplakia were included for differentiation. The results show that OCT yields information about the epithelial surface, thickness and reflectivity, as well as the identifiability of the basement membrane and the vessel network, which could be used to complement the visual clinical appearance of OLP variants and allow a more accurate localization of the OLP center. This forms the basis for further studies on OCT-assisted non-invasive clinical classification of OLP, with the aim of enabling decision support for biopsy sampling in the future.

Identification of Healthy Tissue from Malignant Tissue in Surgical Margin Using Raman Spectroscopy in Oral Cancer Surgeries

Accurate identification of tissue types in surgical margins is essential for ensuring the complete removal of cancerous cells and minimizing the risk of recurrence. The objective of this study was to explore the clinical utility of Raman spectroscopy for the detection of oral squamous cell carcinoma (OSCC) in both tumor and healthy tissues obtained from surgical resection specimens during surgery. This study enrolled a total of 64 patients diagnosed with OSCC. Among the participants, approximately 50% of the cases were classified as the most advanced stage, referred to as T4. Raman experiments were conducted on cryopreserved tissue samples collected from patients diagnosed with OSCC. Prominent spectral regions containing key oral biomarkers were analyzed using the partial least squares-support vector machine (PLS-SVM) method, which is a powerful multivariate analysis technique for discriminant analysis. This approach effectively differentiated OSCC tissue from non-OSCC tissue, achieving a sensitivity of 95.7% and a specificity of 93.3% with 94.7% accuracy. In the current study, Raman analysis of fresh tissue samples showed that OSCC tissues contained significantly higher levels of nucleic acids, proteins, and several amino acids compared to the adjacent healthy tissues. In addition to differentiating between OSCC and non-OSCC tissues, we have also explored the potential of Raman spectroscopy in classifying different stages of OSCC. Specifically, we have investigated the classification of T1, T2, T3, and T4 stages based on their Raman spectra. These findings emphasize the importance of considering both stage and subsite factors in the application of Raman spectroscopy for OSCC analysis. Future work will focus on expanding our tissue sample collection to better comprehend how different subsites influence the Raman spectra of OSCC at various stages, aiming to improve diagnostic accuracy and aid in identifying tumor-free margins during surgical interventions.

Knowledge, Opinions, and Practices of Oral Cancer Prevention among Palestinian Practicing Dentists: An Online Cross-Sectional Questionnaire

Oral-health professionals play a critical role in the early recognition and prevention of oral cancer; however, most patients are diagnosed in the advanced stages that demonstrate poor prognosis. Therefore, this study aimed to investigate the knowledge, opinions, and clinical practices of practicing dentists related to oral cancer prevention and oral mucosal screening in Palestine. This research used an online cross-sectional questionnaire design. Practicing dentists in Palestine completed the 44-item questionnaire encompassing the following four sections: (a) personal data (6 items); (b) oral cancer knowledge (21 items); (c) opinions and beliefs related to oral cancer (10 items); and (d) clinical practices related to oral cancer (7 items). The questionnaire was sent to all eligible participants (N = 650) between July and September of 2022. The response rate was 39.1% (N = 254). About 70.1% of the respondents had poor knowledge of oral cancer and its risk factors, and almost 84.3% had positive opinions related to oral cancer prevention and oral mucosal screening. Concerning the clinical practices, only 29.9% routinely examined their patients every time their patients visited. More experienced dentists showed significantly more positive opinions and better clinical practices related to oral cancer prevention and screening; however, they had significantly lower knowledge scores compared with the younger dentists (p < 0.05). Inadequate training was the most reported perceived boundary against routine oral cancer screening. Palestinian dentists appeared to have positive opinions related to oral cancer prevention and oral mucosal screening. However, the assessment of the knowledge and clinical practices revealed deficiencies in this regard.

LncRNA DS Cell Adhesion Molecule Antisense RNA 1 Facilitates Oral Squamous Cell Carcinoma Progression through The microRNA-138-5p/ Enhancer of Zeste 2 Polycomb Repressive Complex 2 Subunit Axis

Objective

A lot of lncRNAs are implicated in oral squamous cell carcinoma (OSCC) progression. The study aimed at investigating lncRNA DS cell adhesion molecule antisense RNA 1 (DSCAM-AS1)'s functional role and molecular mechanism in OSCC.

Materials and Methods

In this experimental study, a total of 46 pairs of OSCC samples and para-cancerous tissues were collected during surgery. In OSCC tissues and cell lines, quantitative real time polymerase chain reaction (qRTPCR) was performed for detecting DSCAM-AS1 and microRNA-138-5p (miR-138-5p) expression levels. Western blot was conducted to examine the enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) expression level. Then, DSCAM-AS1 was knocked down with siRNA in OSCC cells and MTT and EdU assays were conducted to evaluate OSCC cell proliferation. Transwell assay was utilized for detecting OSCC cell migration and invasion capacities. Besides, the relationships among DSCAM-AS1, miR-138-5p, and EZH2 were explored through RNA immunoprecipitation, dual-luciferase reporter assay, qRT-PCR, and Western blot.

Results

DSCAM-AS1 expression was remarkably increased in OSCC tissues and cell lines, and DSCAM-AS1 knockdown could significantly restrain OSCC cell proliferation, migration, and invasion. MiR-138-5p was identified as a target of DSCAM-AS1, and its inhibitor could reverse the suppressive effects of DSCAM-AS1 knockdown on OSCC progression. EZH2 was verified as a target of miR-138-5p, and EZH2 knockdown could counteract the promotional impact of miR-138-5p inhibitor on OSCC progression. Additionally, DSCAM-AS1, as a ceRNA, could regulate EZH2 expression via miR-138-5p.

Conclusion

DSCAM-AS1 can play a tumor-promoting role in OSCC via miR-138-5p/EZH2 axis.

Role of Fluorescence Imaging Device in Screening of Oral Cancer: A Cross-Sectional Study in Chhattisgarh Population

Background:

Oral squamous cell carcinoma is a major health issue worldwide. Screening and early diagnosis are the key elements for the better prognosis of potentially malignant oral disorders.

Objectives:

This study establishes the effectiveness of fluorescence imaging device in the early detection and precise examination of the normal-appearing oral mucosa of tobacco chewer patients in white light and fluorescence light.

Materials and Methods:

The study consists of a total of 150 patients equally categorized into frequent tobacco chewers with normal mucosa, precancerous lesion, and cancerous lesion. Out of which 10 cases were excluded due to technical errors and consent-related issues. The correlation between examined oral mucosa under white light and fluorescence light was evaluated through a 2 × 3 contingency table Chi-square test.

Results:

Out of 140 participants with a positive cancer diagnosis, there are 43 and 53 patients were sensitive to white light andfluorescence light, respectively. The estimated values for sensitivity and specificity were 0.83 (95% confidence interval: 0.736–0.906) for biopsy report diagnosis.

Conclusions:

Although autofluorescence device plays a critical role in the diagnosis of precancerous oral mucosal lesions in the early stages, the histopathological evaluation remains the gold standard diagnostic approach for this life-threatening disease. Due to the high sensitivity of autofluorescence examination, it has a vital role in determining high-risk oral lesions (precancerous) and oral cancer in mass screening programs for the cancer-prone population.

LINC01355 Contributes to Malignant Phenotype of Oral Squamous Cell Carcinoma and Cytotoxic T Cell Infiltration via Activating Notch Signaling Pathway

LINC01355 has been demonstrated to be dysregulated in several cancers. However, the exact molecular function of LINC01355 in the pathogenesis of OSCC remains unstudied. Here, we reported the effect of LINC01355 in OSCC and investigated the mechanisms. Firstly, we found that the results indicated LINC01355 was increased in OSCC cells. Knockdown of LINC01355 repressed OSCC cell proliferation, migration, and invasion. Recently, immunotherapy is a significant method for the treatment of cancers, in which CD8+ T cells exhibit a significant role. The influence of LINC01355 on the antitumor activity of CD8+ T cells was also focused in this study. As shown, the silence of LINC01355 could repress OSCC tumor growth via inducing CD8+ T cell immune responses. In addition, we found that downregulation of LINC01355 significantly restrained CD8+ T cell apoptosis, induced CD8+ T cell percentage, and enhanced the cytolysis activity when cocultured with OSCC cells. It has been reported that the Notch pathway represses CD8+ T cell activity in cancer patients. In our present study, we displayed that lack of LINC01355 suppressed OSCC malignant behaviors and enhanced the antitumor activity of CD8+ T cells via inactivating Notch signaling. We showed that decreased LINC01355 significantly restrained the Notch signal via a decrease of Notch-1, JAG-1, and HES-1. Repression of Notch1 reversed the effect of LINC01355 in OSCC cells. In conclusion, it was implied that LINC01355 might induce the development of OSCC via modulating the Notch signal pathway, which could provide a candidate therapeutic target for OSCC.

Recent Advances in Nano-Bio-Sensing Fabrication Technology for the Detection of Oral Cancer

Nanotechnology-based miniaturized devices have been a breakthrough in the pre-clinical and clinical research areas, e.g. drug delivery, personalized medicine. They have revolutionized the discovery and development of biomarker-based diagnostic devices for detection of various diseases such as tuberculosis, malaria and cancer. Nanomaterials (NMs) hold tremendous diagnostic potential due to their high surface-to-volume ratio and quantum confinement phenomenon, improving the detection limit of clinically relevant biomolecules in bio-fluids. Thus, they are helpful in the translation of bench-on platform to point-of-care (POC) screening device. The nanomaterial-based biosensor fabrication technology has also simplified and improved oral cancer (OC) or oral squamous cell carcinomas (OSCC) diagnosis. The fabrication of nano-bio sensors involves application specific modifications of NMs. The unique properties functionalized NMs have augmented their application on the nano-biosensing platform for the detection of clinically relevant biomolecules in bio-fluids. Therefore, this article summarizes the recent advancements in the process of fabrication of nano-biosensors for detection of OC.

Silencing of LINC00284 inhibits cell proliferation and migration in oral squamous cell carcinoma by the miR-211-3p/MAFG axis and FUS/KAZN axis

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies worldwide. Emerging evidence has suggested that long noncoding RNAs (lncRNAs) play vital roles in various biological processes of cancers, such as cell proliferation, migration, invasion, and apoptosis. As reported previously, long intergenic non-protein coding RNA 284 (LINC00284) is an important regulator in multiple cancers. However, the biological role, as well as regulatory mechanism of LINC00284 in OSCC, has not been investigated. In our study, RT-qPCR results indicated that LINC00284 was significantly upregulated in OSCC tissues and cells. Moreover, loss-of-function experiments demonstrated that LINC00284 downregulation suppressed cell proliferation and migration and facilitated cell apoptosis. Mechanistically, we found that LINC00284 sponged microRNA 211-3p (miR-211-3p) to upregulate MAF bZIP transcription factor G (MAFG) expression in OSCC cells. Additionally, LINC00284 interacted with FUS protein to increase KAZN mRNA stability. Functional assays showed that either MAFG or KAZN overexpression promoted the malignant behaviors of OSCC cells. Through a series of rescue assays, we found that the inhibitory effect of silencing LINC00284 on OSCC cells can be reversed by upregulated MAFG and KAZN. Overall, silencing LINC00284 inhibits the malignant characteristics of OSCC cells by downregulating MAFG and inhibiting the binding of FUS to KAZN mRNA.

[Autofluorescence visualization of the oral malignant lesions]

OBJECTIVE

The aim of the present paper was to observe the main features of the autofluorescence emission of the oral epithelial carcinomas.

MATERIAL AND METHODS

The study included four patients aged 38-61 years with the oral epithelial carcinomas located at a cheek, a floor of the mouth, a bottom lip. All the diagnoses were later confirmed histologically. The oral cavity was inspected traditionally and then using autofluorescence visualization. For autofluorescence emission excitation we used the home-made LED-based device emitting near 400 nm.

RESULTS

The tissue autofluorescence was visualized in the broad and narrow spectral bands. In comparison with the healthy mucosa the pathological lesions showed the large losses of the green autofluorescence emissions ("dark sport effect") which have been visualized at both spectral bands. The visualization in the broad spectral band allowed to reveal that three lesions had the local sites of red fluorescence of the endogenous porphyrins traditionally connected with the local inflammation.

CONCLUSION

Autofluorescence stomatoscopy is not only important but also mandatory for oncological screening and should be widely used as the additional method of oral mucosa examination in the common dental practice.

Novel Quantitative Analysis Using Optical Imaging (VELscope) and Spectroscopy (Raman) Techniques for Oral Cancer Detection

Simple Summary

Our study aims to develop a novel quantitative analysis method that can increase the oral cancer detection rate for screening oral cancer. We used two different optical techniques, a light-based detection technique (VELScope) and a vibrational spectroscopic technique (Raman spectroscopy). First, we analyzed and evaluated the performance of these two techniques individually using PCA–LDA, and PCA–QDA classifiers. The PCA–LDA of Raman spectroscopy had 82.9% accuracy, 80% sensitivity, and 85.7% specificity, while the region of interests on the autofluorescence images were differentiated with 90% accuracy, 100% sensitivity, and 80% specificity. Afterward, we combined both techniques and evaluated their performance. The combination of two optical techniques can differentiate the cancer and normal groups with 97.14% accuracy, 100% sensitivity, and 94.3% specificity. The main advantage of our study is that we can confirm our results by using two different techniques that are completely independent of each other. That is the reason that the combination of two techniques can increase the sensitivity and specificity.

Abstract

In this study, we developed a novel quantitative analysis method to enhance the detection capability for oral cancer screening. We combined two different optical techniques, a light-based detection technique (visually enhanced lesion scope) and a vibrational spectroscopic technique (Raman spectroscopy). Materials and methods: Thirty-five oral cancer patients who went through surgery were enrolled. Thirty-five cancer lesions and thirty-five control samples with normal oral mucosa (adjacent to the cancer lesion) were analyzed. Thirty-five autofluorescence images and 70 Raman spectra were taken from 35 cancer and 35 control group cryopreserved samples. The normalized intensity and heterogeneity of the 70 regions of interest (ROIs) were calculated along with 70 averaged Raman spectra. Linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA) were used with principal component analysis (PCA) to differentiate the cancer and control groups (normal). The classifications rates were validated using two different validation methods, leave-one-out cross-validation (LOOCV) and k-fold cross-validation. Results: The cryopreserved normal and tumor tissues were differentiated using the PCA–LDA and PCA–QDA models. The PCA–LDA of Raman spectroscopy (RS) had 82.9% accuracy, 80% sensitivity, and 85.7% specificity, while ROIs on the autofluorescence images were differentiated with 90% accuracy, 100% sensitivity, and 80% specificity. The combination of two optical techniques differentiated cancer and normal group with 97.14% accuracy, 100% sensitivity, and 94.3% specificity. Conclusion: In this study, we combined the data of two different optical techniques. Furthermore, PCA–LDA and PCA–QDA quantitative analysis models were used to differentiate tumor and normal groups, creating a complementary pathway for efficient tumor diagnosis. The error rates of RS and VELcope analysis were 17.10% and 10%, respectively, which was reduced to 3% when the two optical techniques were combined.

In Vivo Endoscopic Optical Coherence Tomography of the Healthy Human Oral Mucosa: Qualitative and Quantitative Image Analysis

To date, there is still a lack of reliable imaging modalities to improve the quality of consultation, diagnostic and medical examinations of the oral mucosa in dentistry. Even though, optical technologies have become an important element for the detection and treatment of different diseases of soft tissue, for the case of oral screenings the evidence of the benefit in comparison to conventional histopathology is mostly still pending. One promising optical technology for oral diagnostics is optical coherence tomography (OCT). To prove the potential of OCT, even the amount of freely accessible OCT data is not sufficient to describe the variance of healthy human oral soft tissue in vivo. In order to remedy this deficiency, the present study provides in vivo OCT cross sections of the human oral mucosa of the anterior and posterior oral cavity as well as the oropharynx of 47 adult volunteers. A collection of representative OCT cross sections forms the basis for a randomized blinded image analysis by means of seven criteria to assess the main features of the superficial layers of the human oral mucosa and to determine its correlation to regional features known from hematoxylin and eosin (HE) stained histology.

Healthcare Professional in the Loop (HPIL): Classification of Standard and Oral Cancer-Causing Anomalous Regions of Oral Cavity Using Textural Analysis Technique in Autofluorescence Imaging

Oral mucosal lesions (OML) and oral potentially malignant disorders (OPMDs) have been identified as having the potential to transform into oral squamous cell carcinoma (OSCC). This research focuses on the human-in-the-loop-system named Healthcare Professionals in the Loop (HPIL) to support diagnosis through an advanced machine learning procedure. HPIL is a novel system approach based on the textural pattern of OML and OPMDs (anomalous regions) to differentiate them from standard regions of the oral cavity by using autofluorescence imaging. An innovative method based on pre-processing, e.g., the Deriche-Canny edge detector and circular Hough transform (CHT); a post-processing textural analysis approach using the gray-level co-occurrence matrix (GLCM); and a feature selection algorithm (linear discriminant analysis (LDA)), followed by k-nearest neighbor (KNN) to classify OPMDs and the standard region, is proposed in this paper. The accuracy, sensitivity, and specificity in differentiating between standard and anomalous regions of the oral cavity are 83%, 85%, and 84%, respectively. The performance evaluation was plotted through the receiver operating characteristics of periodontist diagnosis with the HPIL system and without the system. This method of classifying OML and OPMD areas may help the dental specialist to identify anomalous regions for performing their biopsies more efficiently to predict the histological diagnosis of epithelial dysplasia.

Clinico-pathological correlation of optical fluorescence imaging in oral mucosal lesions

OBJECTIVES

This study aimed to identify clinical and pathological characteristics of oral mucosal lesions that may be predictive of optical autofluorescence imaging patterns.

METHODS

Clinical data and archival histopathological material were collected from patients who presented with at least one oral mucosal lesion and underwent assessment via conventional oral examination, optical autofluorescence imaging and histopathological analysis. An open-source digital pathology image analysis software was used to perform histomorphometric measurements. Classification and regression trees were used to determine histopathological characteristics most predictive of a clinical autofluorescence outcome.

RESULTS

Histomorphometric features associated with tissue architecture, epithelial changes, inflammation and vasculature were found to be significantly associated with autofluorescence patterns. Diascopic fluorescence was found to be significantly predicted by lichenoid inflammation and was significantly associated with a diagnosis of oral lichen planus. Loss of autofluorescence with partial blanching was significantly associated with histopathological features noted in dysplastic and malignant lesions.

CONCLUSIONS

This study provides evidence for the use of diascopic fluorescence as a technique to aid in clinical differentiation of benign inflammatory lesions from potentially malignant pathology. Based on the findings of this study, optical fluorescence imaging is a technique of added value in discernment of oral mucosal lesions, and our results support its clinical use.

Gene expression analysis of autofluorescence margins in leukoplakia and oral carcinoma: A pilot study

OBJECTIVES

Autofluorescence is considered a useful technique in the early detection of oral mucosal alterations. However, its efficacy to discriminate tumor margins is still under debate. The purpose of this pilot study was to confirm the existence of molecular divergence from the center of a lesion compared to white light and autofluorescence (VELscope^TM ) visualized margins in leukoplakia and oral carcinoma.

MATERIALS AND METHODS

Molecular divergence from the center of the lesion to white light and VELscope^TM defined margins was compared in patients with leukoplakia (n = 3) and oral carcinoma (n = 4). Expression profiling of 45 selected genes was performed through custom-made TaqMan arrays. Gene Ontology was used for biological pathway analysis.

RESULTS

Irrespective of pathology, the greatest molecular divergence existed between the center of the lesion and both white light and VELscope^TM margins. VELscope^TM and white light margins were also molecularly distinct in oral carcinoma samples. Indeed, the white light margin retained molecular abnormalities observed in the center of the lesion thus suggesting the existence of a "partially transformed" cell population.

CONCLUSION

Despite the limited low number of patients, our data confirm the benefit of combining autofluorescence with conventional oral examination in identifying surgical margins during biopsy procedures for leukoplakia and oral carcinoma.

Long Noncoding RNA RC3H2 Facilitates Cell Proliferation and Invasion by Targeting MicroRNA-101-3p/EZH2 Axis in OSCC

In our previous studies, enhancer of zeste homolog 2 (EZH2) has been proven to be a key oncogenic driver in oral squamous cell carcinoma (OSCC). However, the regulatory mechanisms on EZH2 remain poorly understood in OSCC. Here, through multi-transcriptomics, bioinformatics analysis, and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), the co-expression network of long noncoding RNA RC3H2 (RC3H2), microRNA-101-3p (miR-101-3p), and EZH2 were screened and validated as a competing endogenous RNA (ceRNA) mechanism in OSCC. Silencing of RC3H2 inhibited OSCC cell proliferation, colony formation, migration, and invasion in vitro and reduced the expression of EZH2 and H3K27Me3, whereas RC3H2 overexpression significantly promoted OSCC cell growth, colony formation, migration, invasion, and xenograft tumor growth in vivo and increased the expression of EZH2 and H3K27Me3. A fluorescence in situ hybridization (FISH) assay verified that RC3H2 was predominately localized to the cytoplasm. RNA pull-down and luciferase activity assays showed that miR-101-3p was physically bound to RC3H2 as well as EZH2, and its inhibitor reversed the inhibitory effect of RC3H2 knockdown on progression of OSCC. Taken together, our findings demonstrate that RC3H2 as completive endogenous RNA sponging miR-101-3p targets EZH2 and facilitates OSCC cells' malignant behavior.

Multiclass classification of autofluorescence images of oral cavity lesions based on quantitative analysis

Background

Oral cancer is one of the most common diseases globally. Conventional oral examination and histopathological examination are the two main clinical methods for diagnosing oral cancer early. VELscope is an oral cancer-screening device that exploited autofluorescence. It yields inconsistent results when used to differentiate between normal, premalignant and malignant lesions. We develop a new method to increase the accuracy of differentiation.

Materials and methods

Five samples (images) of each of 21 normal mucosae, as well as 31 premalignant and 16 malignant lesions of the tongue and buccal mucosa were collected under both white light and autofluorescence (VELscope, 400-460 nm wavelength). The images were developed using an iPod (Apple, Atlanta Georgia, USA).

Results

The normalized intensity and standard deviation of intensity were calculated to classify image pixels from the region of interest (ROI). Linear discriminant analysis (LDA) and quadratic discriminant analysis (QDA) classifiers were used. The performance of both of the classifiers was evaluated with respect to accuracy, precision, and recall. These parameters were used for multiclass classification. The accuracy rate of LDA with un-normalized data was increased by 2% and 14% and that of QDA was increased by 16% and 25% for the tongue and buccal mucosa, respectively.

Conclusion

The QDA algorithm outperforms the LDA classifier in the analysis of autofluorescence images with respect to all of the standard evaluation parameters.

A Meta-analysis on efficacy of auto fluorescence in detecting the early dysplastic changes of oral cavity

Background

Light-based detection agents using autofluorescence may be helpful in the detection of early dysplasia, which would otherwise be misdiagnosed as nondysplastic by conventional oral examination (COE) with white light. Visually-enhanced lesion scope (VELscope) is one of such an aid used for the purpose. A meta-analysis was carried out on the sensitivity and specificity of VELscope that would enable in providing evidence of its usage in oral dysplasia.

Materials and Methods

MeSH terms such as auto florescence in oral dysplasia, VELscope, Oral ID, Identifi, in a different medical database such as PubMed, Cochrane, EBSCO, and Google scholar was carried out by four research associates. The total articles available were 242, of which, 230 were excluded based on strict criteria of randomized control trials and proper design. Finally, only 12 studies were chosen for the present analysis. Of 1643 patients from 12 studies, 1264 patients had undergone the autofluorescence examination after the COE. Only 774 patients have shown the loss of fluorescence with VELScope examination and 487 had retained the fluorescence. Biopsy was performed on 1176 patients after the autofluorescence examination in the areas where there was the loss of fluorescence. The available data were subjected to software Review Manager for analysis.

Results and Discussion

Of the 11 studies analyzed, majority of them showed that the autofluorescence device were sensitive enough > 0.70; however, the values of sensitivity and specificities varied significantly. With the VELscope the diagnostic performance of the inexpert examiner was not improved, obtaining a sensitivity of 0.40 (95% of confidence interval [CI]: 0.406-0.773) and a specificity of 0.80 (95% CI: 0.614-0.923).

Conclusion

The new technique may help as an adjunct to histopathology in detecting the dysplasia initially and stop further progression to the carcinoma.

Oral epithelial dysplasia: Causes, quantification, prognosis, and management challenges

Oral epithelial dysplasia is a spectrum of architectural and cytological epithelial changes caused by accumulation of genetic changes, and is associated with an increased risk of progression to squamous cell carcinoma. It is a microscopic diagnosis of immense clinical importance. The initial reports of oral potentially malignant disorders with oral epithelial dysplasia transforming to oral cancer helped in understanding the nature of oral malignancies. Since then, clinical studies on oral potentially malignant disorders have combined microscopic findings of oral epithelial dysplasia to assess the malignant transformation potential of different grades of epithelial dysplasia. A significant amount of scientific literature has amassed on oral epithelial dysplasia relating to aspects of its diagnosis and management. However, the evidence base is weak as a result of the significant variability of published research. Poorly described study methods, variability in different oral epithelial dysplasia grading systems, inter- and intra-examiner variability causing issues of reliability, inadequate sample size, and inconsistent durations of follow-up are some of the methodological issues contributing to the failure to provide dependable information. Randomized clinical trials on the malignant transformation potential of oral epithelial dysplasia and its treatment outcomes are limited. This comprehensive literature review on oral epithelial dysplasia summarizes the scientific knowledge published in the scientific literature in English since its first description. The historical development, etiological factors, grading systems, diagnostic criteria, assessment of risk factors and prevention of malignant transformation, management principles of different grades of oral epithelial dysplasia (surgical and nonsurgical), recommendations on follow-up, and prognostic indicators are discussed in detail.

Interobserver and intraobserver variability affecting the assessment of loss of autofluorescence of oral mucosal lesions

OBJECTIVES

The assessment of loss of tissue autofluorescence (LAF) has been proposed as an adjunct to comprehensive oral examination to enhance the detection of mucosal lesions harbouring dysplasia or carcinoma. The assessment of LAF is not based on completely objectified parameters therefore intraobserver and interobserver variability cannot be neglected alongside the issue of correct interpretation of LAF. The present study evaluated intraobserver and interobserver variability in the clinical assessment of LAF as performed by oral medicine practitioners (OMPs) or general dental practitioners (GDPs).

MATERIALS AND METHODS

Couples of clinical pictures, acquired under white incandescent dental operatory light and during the assessment of LAF performed by VELscope were retrieved. Four OMPs and eight GDPs were asked to assess the pictures and to score the LAF. Kappa statistics allowed the assessment of intra- and inter-observer related variability.

RESULTS

Pictures of 109 lesions representative of all oral mucosal sites and clinical appearances were selected. OMPs had a better intraobserver agreement than GDPs (substantial versus moderate). The moderate (k = 0.506) interobserver agreement observed among both OMPs and GDPs in a 2-score model (positive versus negative), lowered down to poor values only among GDPs when a 3-score or 4-score model (including uncertain judgements) was applied.

CONCLUSIONS

A good agreement (k>0.8) was never observed and the present results are similar to previously reported data about conventional oral examination. Irrespective of the diagnostic accuracy, the assessment of AF seems not to be able to improve observer-related variability in the clinical assessment of oral mucosal lesions.

Potential role of autofluorescence imaging in determining biopsy of oral potentially malignant disorders: A large prospective diagnostic study

Autofluorescence examination of oral tissues using the VELscope has been suggested as an adjunctive tool for cancer detection and diagnosis. This study aimed to determine the diagnostic value of VELscope in a large prospective study of 517 patients with oral potentially malignant disorders (OPMD). For the outcome assessments of discrimination of carcinoma form general OPMD and distinguishing high-risk lesions (moderate/severe dysplasia and carcinoma) from low-risk lesions (no/mild dysplasia), high sensitivity (100% and 95.9% respectively) and negative predictive value (100% and 98.2% respectively) were observed. All the carcinoma and showed loss of autofluorescence (LAF) and only 3 (0.6%) moderate/severe dysplasia were observed without LAF. These data indicate that the cases without LAF using VELscope substantially rule out the presence of high-risk lesions including cancer. This may prove to be useful specially to alleviate patient anxiety regarding a clinically suspicious oral lesion without the LAF, and to avoid a unnecessary biopsy for these cases. Collectively, a perspective to highlight was that a no biopsy strategy may be appropriate for OPMD without LAF using VELscope after conventional oral examination.

Method for diagnosing neoplastic lesions by quantitative fluorescence value

Fluorescence visualization devices (FVs) are useful for detecting malignant lesions because of their simple and noninvasive application. However, their quantitative application has been challenging. This study aimed to quantitatively and statistically evaluate the change in fluorescence intensity (FI) during the progression from normal epithelium to squamous cell carcinoma using a reproducible animal tongue carcinogenesis model. To establish this model, rats were treated with 50 ppm 4-Nitroquinoline 1-oxide (4NQO) in their drinking water for 10, 15, and 20 weeks. After 4NQO administration, each rat tongue was evaluated by gross observation, histology, and FI measurements. Fluorescence images were captured by FV, and ImageJ was used to measure FI, which was analyzed quantitatively and statistically. The establishment of a reproducible tumor progression model was confirmed, showing precancerous lesions (low-grade dysplasia [LGD]), early cancers (high-grade dysplasia/carcinoma in situ [HGD/CIS]), and advanced cancers (Cancer). This carcinogenesis model was quantitatively evaluated by FI. The FI of LGD stage was 54.6, which was highest intensity of all groups. Subsequently, the HGD/CIS and Cancer stages showed decreased FI (HGD/CIS: 46.1, Cancer: 49.1) and manifested as dark spots. This result indicates that FI had more variation and a wider range with increasing tumor progression. We demonstrated that FI migration and an uneven distribution are consistent with tumor progression. Since each step of tumor progression occurs reproducibly in this animal model, statistical evaluation was possible. In addition, tumor progression can be monitored by this new FI analysis method in humans.

Optical fluorescence imaging in oral cancer and potentially malignant disorders: A systematic review

OBJECTIVES

This study aimed to systematically review the efficacy of direct optical fluorescence imaging as an adjunct to comprehensive oral examination in the clinical evaluation, risk assessment and surgical management of oral cancer and potentially malignant disorders.

METHODS

Studies adopting autofluorescence devices, evaluating the efficacy of comprehensive oral examination and optical fluorescence imaging in detection, visualisation or management of oral squamous cell carcinoma or oral potentially malignant disorders, as well as discriminating oral epithelial dysplasia from other mucosal lesions, were included in the literature search across bibliographic databases until October 2018.

RESULTS

Twenty-seven studies were found to be eligible for inclusion in qualitative analysis. Of these, only six studies demonstrated a low risk of bias across all domains of the methodological assessment tool (QUADAS-2). Optical fluorescence imaging demonstrated positive results, with higher sensitivity scores, increased lesion detection and visualisation than comprehensive oral examination alone in the clinical evaluation of oral squamous cell carcinoma and oral potentially malignant disorders.

CONCLUSIONS

This review provides promising evidence for the utilisation of optical fluorescence imaging as an adjunct to comprehensive oral examination in varying clinical settings. It is important that devices utilising optical fluorescence imaging are viewed strictly as clinical adjuncts and not specifically as diagnostic devices.

Role of modern imaging techniques for the in vivo diagnosis of lichen planus

Lichen planus (LP) is a chronic inflammatory skin disease that can sometimes affect mucosal surfaces, with unknown pathogenesis, even though it appears to be an autoimmune disease. The diagnosis of lichen planus is usually based on histopathological examination of the lesions. Nowadays, the classical invasive diagnostic methods are replaced by modern non-invasive techniques. In this review, we present the main non-invasive imaging methods (dermoscopy, reflectance confocal microscopy, optical coherence tomography, ultrasound and diffuse reflection spectrophotometry) used in the diagnosis and therapeutic monitoring of lichen planus. Dermoscopy is a non-invasive method initially used for diagnosis of pigmented tumors but now is used also for inflammatory and infectious skin diseases. In lichen planus, the dermoscopy increases the accuracy of diagnosis, avoids skin biopsies commonly used and can be useful in the therapeutic monitoring by repeated investigation at different stages of treatment. Reflectance confocal microscopy (RCM) is a novel non-invasive imaging technique that is prevalently used for the diagnosis of skin tumors and inflammatory skin diseases. This technology has been mostly employed for bedside, real-time microscopic evaluation of psoriasis, lichen planus, contact dermatitis, revealing specific confocal features to support clinical diagnosis and assist with patient management. Optical coherence tomography (OCT) is an emergent imaging technique, developed over the last decade, based on the interaction of the infrared radiation (900–1,500 nm) and the living tissues. A limited information exists on the benefits of OCT technology for the in vivo diagnosis of LP but could be a useful auxiliary tool in the in vivo differential diagnosis, especially in clinical equivocal settings like mucosal lesions, and in monitoring the response to treatment. Our review shows the possibility of using modern imaging techniques for the in vivo diagnosis and also for evaluation of the treatment response.

An Overview on Current Non-invasive Diagnostic Devices in Oral Oncology

Oral squamous cell carcinoma (OSCC) is the most common head and neck malignancy, and despite advances in cancer therapies, the overall 5-year survival rate has remained below 50% over the past decades. OSCC is typically preceded by potentially malignant disorders (PMD), but distinguishing high-risk from low-risk PMD is challenging. In the last years, several diagnostic methods as light-based detection systems (LBDS) have been proposed to facilitate the detection of OSCC and PMD. Furthermore, the recent evolution of nanotechnology may provide new opportunities to detect PMD and OSCC at an early stage. Indeed, several preclinical studies showed the potential of nanotechnology to enhance diagnostic accuracy. For these reasons, it is fundamental to conduct studies to evaluate the efficacy of nanotechnology implementation in LBDS. The aim of this article is to review the current literature on LBDS and to provide a summary of the sensitivity and specificity of each technique, and possible future applications of nanotechnologies. The LBDS showed great potential for screening and monitoring oral lesions, but there are several factors that hinder an extensive use of these devices. These devices seem to be useful in assessing lesion margins that must be biopsied. However, to date, conventional oral examination, and tissue biopsy remain the gold standard for OSCC diagnosis. The use of nanotechnologies could be the next step in the evolution of LBDS, thus providing devices that can help clinicians to detect and better monitor oral lesions.

Comparative evaluation of autofluorescence imaging and histopathological investigation for oral potentially malignant disorders in Taiwan

OBJECTIVES

Autofluorescence imaging is gaining popularity as an adjunctive test for oral potentially malignant disorders (OPMD). This study evaluated the efficacy of autofluorescence imaging based on the current standard oral mucosal disorder checklist in Taiwan.

MATERIALS AND METHODS

In total, 126 patients suspected to have mucosal disorders at the Division of Oral and Maxillofacial Surgery, Tri-Service General Hospital, Taipei, Taiwan, were enrolled. Following a conventional oral examination by using the oral mucosal disorder checklist and an autofluorescence imaging examination, all participants underwent histopathological examination to access epithelial dysplasia.

RESULTS

Among 126 patients, 68 patients were diagnosis as having an OPMD and 63 having epithelial dysplasia. Autofluorescence imaging exhibited a sensitivity, specificity, positivity predictive value (PPV), negative predictive value (NPV), and accuracy of 77.94%, 35.42%, 63.10%, 53.13%, and 60.34%, respectively, for OPMD and of 88.89%, 43.86%, 63.64%, 78.13%, and 67.50%, respectively, for epithelial dysplasia. After the exclusion of 48 non-OPMD cases according to the checklist, the sensitivity, specificity, PPV, NPV, and accuracy of autofluorescence imaging became 87.50%, 72.73%, 94.23%, 53.33%, and 85.07%, respectively, for epithelial dysplasia.

CONCLUSION

The efficacy of epithelial dysplasia identification and OPMD risk assessment can be increased after the exclusion of the non-OPMD cases through autofluorescence imaging.

CLINICAL RELEVANCE

Autofluorescence imaging is a useful adjunct that can assist specialists in assessing OPMD patients prone to dysplasia without compromising patient care.

Narrow Band Imaging-guided resection of oral cavity cancer decreases local recurrence and increases survival

PURPOSE

Overall local recurrence of oral squamous cell carcinoma (OSCC) is estimated at 20%. Incomplete primary tumour excision contributes to localised postsurgical recurrence of OSCC. The purpose of this study was to report on patient outcomes following resection of OSCC using Narrow Band Imaging (NBI).

MATERIALS AND METHODS

Patients with OSCC requiring resection were visualised under conventional white light (WL) then NBI using an Olympus NBI ENF-VQ nasendoscope with CLV-180 light source and processor (Olympus Medical Systems, Tokyo, Japan). OSCC tissue was resected to the NBI-defined surgical margins, and patients followed for a minimum of 5 years postsurgery to assess local recurrence rate (LRR) and disease-free survival (DFS).

RESULTS

Of the 20 patients recruited for this study, one patient (5%) declined follow-up. At the latest follow-up period (up to 7 years postsurgery), 14 of 19 patients (73.68%) were alive with no recurrence. Two patients (10.53%) had died from metastatic disease with no local recurrence, one patient (5.26%) had died from disease with local recurrence, and two patients (10.53%) had died disease-free from other causes. In total, 16 of 19 patients (84.21%) who were followed for a minimum of 5 years were still alive and had not developed local recurrence. Only one patient developed local recurrence. Five-year DFS was 84.21% and LRR was 5.26%.

CONCLUSION

Resection to NBI-defined margins improves survival rates and decreases recurrence rates of OSCC compared to traditional methods and should be adopted as the new gold standard for determining mucosal surgical margins for treatment of oral cavity cancer. These promising results have set the scene for a multicentred randomised controlled trial comparing NBI to WL currently underway.

In-vivo optical imaging in head and neck oncology: basic principles, clinical applications and future directions

Head and neck cancers become a severe threat to human's health nowadays and represent the sixth most common cancer worldwide. Surgery remains the first-line choice for head and neck cancer patients. Limited resectable tissue mass and complicated anatomy structures in the head and neck region put the surgeons in a dilemma between the extensive resection and a better quality of life for the patients. Early diagnosis and treatment of the pre-malignancies, as well as real-time in vivo detection of surgical margins during en bloc resection, could be leveraged to minimize the resection of normal tissues. With the understanding of the head and neck oncology, recent advances in optical hardware and reagents have provided unique opportunities for real-time pre-malignancies and cancer imaging in the clinic or operating room. Optical imaging in the head and neck has been reported using autofluorescence imaging, targeted fluorescence imaging, high-resolution microendoscopy, narrow band imaging and the Raman spectroscopy. In this study, we reviewed the basic theories and clinical applications of optical imaging for the diagnosis and treatment in the field of head and neck oncology with the goal of identifying limitations and facilitating future advancements in the field.

Oral cancer screening practices of oral health professionals in Australia

Background

To evaluate oral cancer-related screening practices of Oral Health Professionals (OHPs - dentists, dental hygienists, dental therapists, and oral health therapists) practising in Victoria, Australia.

Methods

A 36-item survey was distributed to 3343 OHPs. Items included socio-demographic and work-related characteristics; self-assessed knowledge of oral cancer; perceived level of confidence in discussing oral health behaviors with patients; oral cancer screening practices; and self-evaluated need for additional training on screening procedures for oral cancer.

Results

A total of 380 OHPs responded this survey, achieving an overall response rate of 9.4%. Forty-five were excluded from further analysis. Of these 335 OHP, 72% were dentists; (n = 241); either GDP or Dental Specialists; 13.7% (n = 46) were dental hygienists; 12.2% (n = 41) were oral health therapists, and the remaining 2.1% (n = 7) were dental therapists. While the majority (95.2%) agreed that oral cancer screening should be routinely performed, in actual practice around half (51.4%) screened all their patients. Another 12.8% “Very rarely” conducted screening examinations. The probability of routinely conducting an oral cancer screening was explored utilising Logistic Regression Analysis. Four variables remained statistically significant (p < 0.0001). Results indicate that the likelihood of conducting an oral cancer screening rose with increasing levels of OHPs’ confidence in oral cancer-related knowledge (OR = 1.35; 95% CI: 1.09–1.67) and with higher levels of confidence in discussing oral hygiene practices with patients (OR = 1.25; 95% CI: 1.03–1.52). Results also showed that dental specialists were less likely to perform oral cancer screening examinations compared with other OHPs (OR = 0.18; 95% CI: 0.07–0.52) and the likelihood of performing an oral cancer screening decreased when the “patient complained of a problem” (OR = 0.21; 95% CI: 0.10–0.44).

Conclusion

Only half the study sample performed oral cancer screening examinations for all of their patients. This study provides evidence of the need for further oral cancer-related education and screening training for OHPs, which is vital to enhance oral cancer prevention and early detection.

Detection accuracy for epithelial dysplasia using an objective autofluorescence visualization method based on the luminance ratio

The autofluorescence visualization method (AVM) uses blue excitation light to assist in the diagnosis of epithelial dysplasia. It detects epithelial dysplasia as a black area, which is known as fluorescence visualization loss (FVL). In this study, we evaluated the detection accuracy for epithelial dysplasia of the tongue using the objective AVM and assessed its possible clinical utility. Seventy-nine tongue specimens clinically suspected to have leukoplakia or squamous cell carcinoma (SCC) were analyzed. First, the AVM was subjectively performed using the Visually Enhanced Lesion scope (VELscope), and the iodine-staining method was then performed. After biopsy, the histopathological results and the luminance ratio between the lesion and healthy tissue were compared, and a receiver operating characteristic curve was created. The cutoff value for the objective AVM was determined; the lesion was considered FVL-positive or -negative when the luminance ratio was higher or lower than the cutoff value, respectively. The histopathological diagnoses among the 79 specimens were SCC (n=30), leukoplakia with dysplasia (n=34), and leukoplakia without dysplasia (n=15). The cutoff value of the luminance ratio was 1.62, resulting in 66 FVL-positive and 13 FVL-negative specimens. The luminance ratio was significantly higher in the epithelial dysplasia-positive than -negative group (P<0.000 1). The objective AVM showed much higher consistency between histopathological results than did the two methods (kappa statistic=0.656). In conclusion, objective autofluorescence visualization has a potential as an auxiliary method for diagnosis of epithelial dysplasia.

The diagnostic value of the native fluorescence visualization device for early detection of premalignant/malignant lesions of the oral cavity

PURPOSE

The present study aimed to determine the diagnostic value of a native fluorescence visualization device in the identification of oral malignant/dysplastic lesions.

METHODS

This study involved 45 patients who had oral lesions that were suspected to be malignant, potentially malignant, or benign. The patients visited the Oral Medicine Department of the Mashhad Dental School. The sensitivity, specificity, positive and negative predictive values, and likelihood ratio of this device were determined.

RESULTS

The histopathological assessment of samples showed 9 cases of oral squamous cell carcinoma and 12 lesions with dysplasia. Ten samples of dysplastic lesions and all malignant lesions appeared dark or red/orange when examined with the native fluorescence visualization device. In 90% of the dysplastic/malignant lesions, the label-free fluorescence results were positive. The sensitivity, specificity, and positive and negative predictive values of this device were 90%, 15%, 40%, and 71%, respectively.

CONCLUSIONS

The native fluorescence visualization device can be used in specialized centers as an adjunctive device to increase the sensitivity of a clinical examination, but is not capable of distinguishing benign lesions from malignant and dysplastic ones due to its low specificity.

Development of a multimodal foveated endomicroscope for the detection of oral cancer

A multimodal endomicroscope was developed for cancer detection that combines hyperspectral and confocal imaging through a single foveated objective and a vibrating optical fiber bundle. Standard clinical examination has a limited ability to identify early stage oral cancer. Optical detection methods are typically restricted by either achievable resolution or a small field-of-view. By combining high resolution and widefield spectral imaging into a single probe, a device was developed that provides spectral and spatial information over a 5 mm field to locate suspicious lesions that can then be inspected in high resolution mode. The device was evaluated on ex vivo biopsies of human oral tumors.

Diagnostic accuracy of Narrow Band Imaging for the detection of oral potentially malignant disorders

OBJECTIVE

To determine the clinical diagnostic accuracy of Narrow Band Imaging(™) for the detection of oral potentially malignant disorders in a prospective series of patients.

MATERIALS AND METHODS

New and existing patients referred to an oral medicine and pathology specialist clinic for assessment of at least one white, red or red-white oral mucosal lesion underwent conventional oral examination, followed by examination with the white light mode and then narrow band imaging mode of a Narrow Band Imaging(™) system. The clinical presentation, microvascular architecture and relevant histopathology of all lesions were recorded.

RESULTS

A total of 272 lesions from 95 patients were observed. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for the detection of oral potentially malignant disorders or worse by Narrow Band Imaging(™) were 100%, 74.63%, 92.38%, 100% and 93.77%, respectively, when compared with conventional oral examination. Narrow Band Imaging(™) aided the detection of 24 lesions undetected by conventional oral examination and 13 lesions undetected by white light endoscopy.

CONCLUSION

Narrow Band Imaging(™) demonstrates great utility as a visualisation adjunct for detecting and monitoring oral potentially malignant diseases, particularly lesions not identified by conventional oral examination or white light examination alone.

Assessment of oral mucosal lesions with autofluorescence imaging and reflectance spectroscopy

BACKGROUND

The aim of this prospective study was to evaluate the efficacy of a new form of autofluorescence imaging and tissue reflectance spectroscopy (Identafi, DentalEZ) in examining patients with oral mucosal lesions.

METHODS

The authors examined 88 patients with 231 oral mucosal lesions by conventional oral examination (COE) using white-light illumination and ×2.5 magnification loupes, followed by examination using Identafi. The authors noted fluorescence visualization loss, the presence of blanching, and diffuseness of vasculature. They performed incisional biopsies to provide definitive histopathologic diagnosis.

RESULTS

Identafi's white light produced lesion visibility and border distinctness equivalent to COE. Identafi's violet light displayed a sensitivity of 12.5% and specificity of 85.4% for detection of oral epithelial dysplasia (OED). The authors noted visible vasculature using the green-amber light in 40.9% of lesions.

CONCLUSIONS

Identafi's intraoral white light provided detailed visualization of oral mucosal lesions comparable with examination using an extraoral white-light source with magnification. A high level of clinical experience is required to interpret the results of autofluorescence examination as the violet light displayed low sensitivity for detection of OED. The green-amber light provided additional clinical information in relation to underlying vasculature and inflammation of lesions.

PRACTICAL IMPLICATIONS

Examination using Identafi can provide clinicians with more clinical data than a standard COE with yellow incandescent light, but the clinical and optical findings should be interpreted as a whole and not in isolation. Clinicians should use the light features of Identafi in a sequential and differential manner.

Screening and referral of oral mucosal pathology: a check-up of Australian dentists

BACKGROUND

Oral squamous cell carcinomas and potentially malignant oral disorders can be detected early by visually inspecting the oral soft tissues. This study aimed to determine Australian dentists' opinions and practices regarding oral mucosal screening, referral and oral cancer prevention.

METHODS

Nine hundred and ninety-nine randomly selected general dentists were mailed a questionnaire. The questionnaire queried practitioners' opinions and perceptions of oral mucosal screening, their referral practices and their beliefs regarding detection and prevention of oral cancer.

RESULTS

A total of n=640 individuals responded, yielding a response rate of 70.2%. Most Australian dentists reported to routinely perform oral mucosal screening. Lack of training, confidence, time and financial incentives were seen as barriers to performing mucosal screening to at least some degree by participants in this study. Most dentists manage referrals for oral mucosal pathology appropriately; however, only about half believe in following up with referred patients. Only half of dentists surveyed believed that they could influence a patient to quit smoking.

CONCLUSIONS

Australian dentists place importance on oral mucosal screening. Some changes to dental education and training could be made to further improve confidence and ability of dentists in detecting and referring oral mucosal pathology.

Techniques for early diagnosis of oral squamous cell carcinoma: Systematic review

Background and objectives

The diagnosis of early oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC) is of paramount clinical importance given the mortality rate of late stage disease. The aim of this study is to review the literature to assess the current situation and progress in this area.

Material and Methods

A search in Cochrane and PubMed (January 2006 to December 2013) has been used with the key words “squamous cell carcinoma”, “early diagnosis” “oral cavity”, “Potentially Malignant Disorders” y “premalignant lesions”. The inclusion criteria were the use of techniques for early diagnosis of OSCC and OPMD, 7 years aged articles and publications written in English, French or Spanish. The exclusion criteria were case reports and studies in other languages.

Results

Out of the 89 studies obtained initially from the search 60 articles were selected to be included in the systematic review: 1 metaanalysis, 17 systematic reviews, 35 prospective studies, 5 retrospective studies, 1 consensus and 1 semi-structured interviews.

Conclusions

The best diagnostic technique is that which we have sufficient experience and training. Definitely tissue biopsy and histopathological examination should remain the gold standard for oral cancer diagnose. In this systematic review it has not been found sufficient scientific evidence on the majority of proposed techniques for early diagnosis of OSCC, therefore more extensive and exhaustive studies are needed.

Key words: Squamous cell carcinoma, early diagnosis, oral cavity, potentially malignant disorders, premalignant lesions.

Late stage diagnosis of oral cancer: components and possible solutions

Stage of disease at the diagnosis of oral cancer is thought to be a significant factor in prognosis and outcome (International Agency for Research on Cancer/World Health Organization, 2014). Unfortunately, we continue to diagnose almost 2/3 of these cancers at advanced stages of disease despite the ongoing research for devices/methods to aid the clinicians in detection and accurate oral mucosal lesion diagnosis. This paper explores both the nature of oral cancer and the adjuncts available for detection, and presents the current issues in diagnostic delays of oral cancer detection.

Assessment of a decision making protocol to improve the efficacy of VELscope™ in general dental practice: a prospective evaluation

BACKGROUND

VELscope™ is a device designed to help detect potentially malignant disorders of the oral mucosa at an early stage using direct tissue autofluorescence. Previous research indicates a high rate of false positives using this device. This study assesses a decision making protocol for the detection of oral mucosal lesions using conventional oral examination and VELscope™ in a general dental practice setting.

MATERIALS AND METHODS

305 patients presenting for general dental treatment were screened by a general dental practitioner (GDP) for oral mucosal lesions using incandescent light (conventional oral examination - COE), followed by VELscope™ and then by correlating the findings from these two examinations. A decision making protocol was followed. Patients were either reviewed or referred to an Oral Medicine specialist (OMS) for consultation, and biopsy was undertaken as required for definitive diagnosis.

RESULTS

146 patients presented with at least one oral mucosal lesion, and a total of 222 lesions were detected. COE detected 161 oral mucosal lesions and an additional 61 lesions were detected with VELscope™. COE alone showed a sensitivity of 44.0% and specificity of 99.0% while VELscope™ alone showed a sensitivity of 64.0% and specificity of 54.3%. Using the decision making protocol, the sensitivity and specificity were 73.9% and 97.9% respectively.

CONCLUSION

Using the decision making protocol proposed in this study allows for the detection of additional oral mucosal lesions requiring specialist referral by incorporating VELscope™ into routine general dental practice, without compromising patient care.

The clinical effectiveness of reflectance optical spectroscopy for the in vivo diagnosis of oral lesions

Optical spectroscopy devices are being developed and tested for the screening and diagnosis of oral precancer and cancer lesions. This study reports a device that uses white light for detection of suspicious lesions and green–amber light at 545 nm that detect tissue vascularity on patients with several suspicious oral lesions. The clinical grading of vascularity was compared to the histological grading of the biopsied lesions using specific biomarkers. Such a device, in the hands of dentists and other health professionals, could greatly increase the number of oral cancerous lesions detected in early phase. The purpose of this study is to correlate the clinical grading of tissue vascularity in several oral suspicious lesions using the Identafi^® system with the histological grading of the biopsied lesions using specific vascular markers. Twenty-one patients with various oral lesions were enrolled in the study. The lesions were visualized using Identafi^® device with white light illumination, followed by visualization of tissue autofluorescence and tissue reflectance. Tissue biopsied was obtained from the all lesions and both histopathological and immunohistochemical studies using a vascular endothelial biomarker (CD34) were performed on these tissue samples. The clinical vascular grading using the green–amber light at 545 nm and the expression pattern and intensity of staining for CD34 in the different biopsies varied depending on lesions, grading ranged from 1 to 3. The increase in vascularity was observed in abnormal tissues when compared to normal mucosa, but this increase was not limited to carcinoma only as hyperkeratosis and other oral diseases, such as lichen planus, also showed increase in vascularity. Optical spectroscopy is a promising technology for the detection of oral mucosal abnormalities; however, further investigations with a larger population group is required to evaluate the usefulness of these devices in differentiating benign lesions from potentially malignant lesions.

Oral cancer in Australia 1982-2008: a growing need for opportunistic screening and prevention

BACKGROUND

Globally, a decline in the incidence of oral cancer has been noted, while the mortality rates have remained relatively stable. The aim of this study was to provide an update on the incidence and mortality of oral cancer in Australia on a national and state level.

METHODS

Data regarding new cases and deaths associated with cancer of the lip, oral cavity and oropharynx were obtained from the Australian Institute of Health and Welfare for the period 1982-2008. Crude- and age-standardized incidence and mortality rates were calculated for all of Australia and for each state and territory.

RESULTS

A total of 60 826 cases of lip, oral cavity and oropharyngeal cancer were diagnosed in Australia. Between 1992 and 2008, a decline in the annual percentage change of age-standardized incidence was noted. The lip, followed by the tongue, continue to represent the most common sites of new oral cancer cases. There was no significant change in the rates of mortality for oral cancer over the time period.

CONCLUSIONS

These findings show that the oral cancer mortality rate remains high despite a decline in incidence over the past three decades, highlighting a greater need for dental practitioners to undertake preventive strategies and opportunistic screening for patients.

Efficacy of narrow band imaging for detection and surveillance of potentially malignant and malignant lesions in the oral cavity and oropharynx: a systematic review

OBJECTIVE

Narrow band imaging (NBI) is an endoscopic technique that enhances the mucosal surface texture, and mucosal and submucosal vascular morphology. This paper systematically reviews the available literature regarding the efficacy of NBI for the detection and monitoring of potentially malignant and malignant lesions in the oral cavity and oropharynx.

METHODS

Databases searched included PubMed, EMBASE, Web of Science and Scopus (to September 2013). Additional articles were found by conducting an author publication search using PubMed and by scanning the reference lists of relevant articles. Only trials that investigated and evaluated the effectiveness of both white light (WL) and NBI for aiding the detection of only oral potentially malignant lesions, oral squamous cell carcinomas and/or oropharyngeal squamous cell carcinomas were considered for this review. Two reviewers (ANV and CSF) independently assessed retrieved articles against the criteria, and included articles underwent data extraction and risk of bias assessment.

RESULTS

Two studies, one retrospective and one prospective, met the inclusion criteria. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for WL ranged between 56-96%, 60-100%, 33-100%, 87-99% and 66-89% respectively, whereas it was 87-96%, 94-98%, 73-96%, 97-98% and 92-97% respectively for NBI.

CONCLUSION

While more research is required to determine the full value of NBI, it has great potential in accurately aiding the detection and assessment of neoplastic lesions, and influencing how these lesions are managed.