Proliferative Verrucous Leukoplakia: An Expert Consensus Guideline for Standardized Assessment and Reporting.

The many diverse terms used to describe the wide spectrum of changes seen in proliferative verrucous leukoplakia (PVL) have resulted in disparate clinical management. The objective of this study was to produce an expert consensus guideline for standardized assessment and reporting by pathologists diagnosing PVL related lesions. 299 biopsies from 84 PVL patients from six institutions were selected from patients who had multifocal oral leukoplakic lesions identified over several years (a minimum follow-up period of 36 months). The lesions demonstrated the spectrum of histologic features described in PVL, and in some cases, patients developed oral cavity squamous cell carcinoma (SCC). An expert working group of oral and maxillofacial and head and neck pathologists reviewed microscopic features in a rigorous fashion, in combination with review of clinical photographs when available. The working group then selected 43 single slide biopsy cases for whole slide digital imaging (WSI) review by members of the consensus conference. The digital images were then reviewed in two surveys separated by a washout period of at least 90 days. Five non-PVL histologic mimics were included as controls. Cases were re-evaluated during a consensus conference with 19 members reporting on the cases. The best inter-observer diagnostic agreement relative to PVL lesions were classified as "corrugated ortho(para)hyperkeratotic lesion, not reactive" and "SCC" (chi-square p = 0.015). There was less than moderate agreement (kappa < 0.60) for lesions in the "Bulky hyperkeratotic epithelial proliferation, not reactive" category. There was ≥ moderate agreement (> 0.41 kappa) for 35 of 48 cases. This expert consensus guideline has been developed with support and endorsement from the leadership of the American Academy of Oral and Maxillofacial Pathology and the North American Society of Head and Neck Pathologists to recommend the use of standardized histopathologic criteria and descriptive terminology to indicate three categories of lesions within PVL: (1) "corrugated ortho(para)hyperkeratotic lesion, not reactive;" (2) "bulky hyperkeratotic epithelial proliferation, not reactive;" and (3) "suspicious for," or "squamous cell carcinoma." Classification of PVL lesions based on a combination of clinical findings and these histologic descriptive categories is encouraged in order to standardize reporting, aid in future research and potentially guide clinical management.

Strategic use of obturator prostheses for the rehabilitation of oral cancer patients during the COVID-19 pandemic.

During the current pandemic scenario, maxillofacial rehabilitation specialists involved with supportive care in cancer must transform its practice to cope with COVID-19 and improve protocols that could quickly return the oral function of complex cancer patients who cannot wait for surgical complex rehabilitation. This includes the role of the maxillofacial prosthodontist for the rehabilitation of surgically treated patients with maxillary cancers by the means of filling obturator prostheses that are considered an optimal scientific-based strategy to reduce hospital stay with excellent pain control, oral function (speech, swallowing, mastication, and facial esthetics), psychologic and quality of life outcomes for the patients following intraoral cancer resection. Therefore, the aim of this commentary was to bring new lights to the strategic use of obturator prostheses for the rehabilitation of oral cancer patients during the COVID-19 pandemic as well as to present a protocol for managing such cases.

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

INTRODUCTION: The aim of this study was to perform an audit of oral and maxillofacial specimens submitted for cytological diagnosis to verify the importance of this complementary examination. METHODS: A retrospective analysis of our institutional cytopathology database was performed over an 18-year period. Clinical information and cytological data were collected. Associations between independent variables and outcomes were assessed using the Pearson χ2 test or Fisher's test, with a 5% significance level. When available, the histological diagnosis was compared with cytological diagnosis to identify the percentage of agreement and the specificity, sensitivity and accuracy of cytology in identifying malignant neoplasms. RESULTS: A total of 1082 cases were identified, which included 65 different cytological diagnoses. Exfoliative cytology (EC) was performed in 312 cases (29.1%) and fine needle aspiration cytology (FNAC) in 770 cases (70.9%). EC was mainly employed to diagnose oral infectious diseases (P < 0.001) and FNAC to diagnose neoplasms, cystic, reactive and miscellaneous lesions (P < 0.001). Cell-block was performed in 555 FNAC cases (51.3%). Panoptic, Papanicolaou and haematoxylin-eosin staining were performed in FNAC and periodic acid-Schiff in EC (P < 0.001). In 211 cases (19.5%), the histological diagnosis was available and the percentage agreement with the cytological diagnosis was 41.2%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy to identify malignant neoplasms were 84.6%, 100%, 100%, 77.8% and 90.0%, respectively. CONCLUSIONS: EC was mainly performed for diagnosis of infectious diseases and FNAC for diagnosis of salivary gland tumours, odontogenic lesions, reactive lesions and cervical metastasis.

[Standardized training system for oral and maxillofacial radiology specialist in the United States].

Oral and maxillofacial radiology (OMR) in the United States is one of the nine dental specialties recognized by the American Dental Association (ADA). It has a nearly 100-year history of development and has also established a complete set of specialist training system. Staffing, base facilities, financial status, timing of training courses, contents, plans, and goals to be achieved are all clearly defined. All training centers need to undergo regular assessments every seven years with the ADA's Commission on Dental Accreditation (CODA). After graduation, the specialist graduates can be engaged in the clinical teaching and scientific research of radiological diagnosis in universities or general hospitals. They also have the option to open their own business by setting up imaging diagnostic centers or being specialized in tele-radiology to provide imaging diagnosis or consultation report to clinicians in other disciplines, or even assisting in the development of treatment planning for dental implants and orthodontic procedures. Of course, stomatology and OMR education systems are different in China and the United States due to different national conditions. Although the experience in the United States cannot be completely copied, many concepts, standards and goals of OMR specialty training there have been practiced and improved for a long period of time and are worth learning by the Chinese OMR counterparts or relevant agencies.

Effect of Lecture Attendance and Prerequisite Academic Outcomes on Dental Students' Oral Pathology Performance.

Decreased lecture attendance in undergraduate and health science professions education has been noted throughout the world. The limited study of the effect of lecture attendance on dental students' performance has yielded mixed results, with some studies finding a positive effect and others reporting no association. The aim of this study was to evaluate the effect of lecture attendance on dental students' final grades in an oral pathology course at one U.S. dental school. Due to a curriculum change, second- and third-year students (N=233) were concurrently enrolled in the spring 2016 oral pathology (OP) course. Students' course grades were compared to attendance percentage (Att), grades in prerequisite basic science (PBS) courses, and Academic Average and Total Science (TS) scores on the Dental Admission Test. The results showed that both Att (p=0.011) and TS score (p<0.001) were significant predictors of OP grade, while race, gender, and age were not. Students' grades in OP were moderately to strongly correlated with their grades in all PBS courses (p<0.001). These results suggest that lecture attendance in OP should be encouraged but viewed in light of the finding that it was not as strongly correlated as PBS course performance and was a weaker predictor than TS score. Students with lower TS scores and PBS course grades should be encouraged to use additional supports such as tutoring to improve their performance in OP.

Nested PCR for detection of HSV-1 in oral mucosa

BACKGROUND: It has been estimated that 15%-20% of human tumours are driven by infection and inflammation, and viral infections play an important role in malignant transformation. The evidence that herpes simplex virus type 1 (HSV-1) could be involved in the aetiology of oral cancer varies from weak to persuasive. This study aimed to investigate by nested PCR (NPCR) the prevalence of HSV-1 in samples from normal oral mucosa, oral leukoplakia, and oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: We investigated the prevalence of HSV-1 in biopsies obtained from 26 fresh, normal oral mucosa from healthy volunteers as well as 53 oral leukoplakia and 27 OSCC paraffin-embedded samples. DNA was extracted from the specimens and investigated for the presence of HSV-1 by nested polymerase chain reaction (NPCR) and DNA sequencing. RESULTS: HSV-1 was detected in 14 (54%) of the healthy samples, in 19 (36%) of the oral leukoplakia samples, and in 14 (52%) of the OSCC samples. The differences were not statistically significant. CONCLUSIONS: We observed a high incidence of HSV-1 in healthy oral mucosa, oral leukoplakia, and OSCC tissues. Thus, no connection between OSCC development and presence of HSV-1 was detected

An international survey of speciality training in oral and maxillofacial pathology.

BACKGROUND: Speciality training in oral and maxillofacial pathology (OMFP) across the world would be aided by guidance on a generic curriculum and training programme that all countries could use as a template. In order to facilitate this, we require an understanding of the various forms which OMFP training takes across the world. METHODS: We sent a questionnaire to OMF pathologists in the 42 countries represented in the IAOP membership, via their Regional Councillor. The questionnaire included detailed demographics, entry requirements, specialty training program and facilities/resources. RESULTS: Replies were received from 22/42 countries (52%). OMFP is a dental/dental and medical speciality in 72%, and in 92% of those, this is recognised by a licensing board. Training was undertaken in an academic environment in 85% (with many offering a further academic qualification) and the median length of training was 4 years. General/anatomical pathology training is mandated in 85% of programs and a common core of general sub-specialities was identified. An end of training assessment was conducted in 80% of programs with most including written, practical and oral elements. Training program directors and educational supervisors were in place in 12/16 programs and, in most, Quality Assurance of training was externally monitored. In only one country was the number of trainees linked to workforce planning. CONCLUSIONS: Training in OMFP varies across the world. However, we feel there is sufficient commonality for the development of an agreed indicative framework on education and training in Oral and Maxillofacial Pathology, perhaps under the auspices of the IAOP.

Scandinavian Fellowship for Oral Pathology and Oral Medicine: statement on oral pathology and oral medicine in the European Dental Curriculum.

BACKGROUND: For many years, dentists have migrated between the Scandinavian countries without an intentionally harmonized dental education. The free movement of the workforce in the European Union has clarified that a certain degree of standardization or harmonization of the European higher education acts, including the dental education, is required. As a result of the Bologna process, the Association for Dental Education in Europe and the thematic network DentEd have generated guidelines in the document 'Profile and Competences for the European Dentist' (PCD). This document is meant to act as the leading source in revisions of dental curricula throughout Europe converging towards a European Dental Curriculum. In order to render the best conditions for future curriculum revisions providing the best quality dentist we feel obliged to analyse and comment the outlines of oral pathology and oral medicine in the PCD. METHODS: The representatives agreed upon definitions of oral pathology and oral medicine, and competences in oral pathology and oral medicine that a contemporary European dentist should master. The competences directly related to oral pathology and oral medicine were identified, within the PCD. RESULTS: The subject representatives suggested eighteen additions and two rewordings of the PCD, which all were substantiated by thorough argumentation. PERSPECTIVES: Hopefully, this contribution will find support in future revisions of the PCD in order to secure the best quality dental education.

The future of oral pathology practice.

Oral and maxillofacial pathology (OMP) may be viewed as a specialty of dentistry, which addresses the diagnosis and treatment of diseases of the oral and perioral regions. Consensus definitions may be found in the accreditation standards for OMP as published by the American Dental Association, and in the Constitution and Bylaws of the American Academy of Oral and Maxillofacial Pathology (AAOMP). These sources describe roles for OMP in laboratory diagnosis (histopathology), and clinical practice. Eversole recognizes these divisions of OMP in his discussion of evidence-based practice, noting that oral medicine shares with OMP responsibilities in the care of patients with oral disease. Broadly viewed, all clinical disciplines and specialties of dentistry provide services in disease diagnosis and treatment. However, Eversole makes a distinction between the diagnostic and treatment services provided throughout dentistry, and those offered by OMP, excluding from OMP those primarily focused on dental caries, diseases of the periodontium, missing teeth and tooth structure, and dental misalignment. The focus of this essay addresses the future of OMP practice.

Interobserver reliability in the histopathologic diagnosis of oral pre-malignant and malignant lesions.

BACKGROUND: The histologic classification of pre-cancerous and cancerous oral lesions has generally shown poor agreement between pathologists, but lesion and patient characteristics that may affect diagnostic reliability have not been explored. METHODS: Eighty-seven clinically suspicious oral lesions biopsied from 81 patients with previous upper aerodigestive tract cancer were independently classified by their local pathologist and a central pathology committee. Interobserver reliability between the local pathologist and the central pathology committee was measured with weighted kappa (kappa w) statistics and corresponding 95% confidence intervals (CI). RESULT: The kappa w for pathologic diagnosis was 0.59 (95% CI: 0.45, 0.72), and was higher for lesions without inflammation (0.67 (95% CI: 0.53, 0.80) than inflamed lesions (-0.10 (95% CI: -0.27, 0.07)). Greatest agreement was seen for lesions located in the buccal mucosa/vestibule (kappa w = 0.68 (95% CI: 0.46, 0.91)) and tongue (kappa w = 0.62 (95% CI: 0.40, 0.84)). Least agreement was found for lip/labial mucosa lesions (kappa w = -0.04 (95% CI: -0.34, 0.27)). Punch biopsies (kappa w = 0.67 (95% CI: 0.54, 0.80)) had greater interobserver reliability than wedge biopsies (kappa w = 0.38 (95% CI: 0.12, 0.64)). CONCLUSIONS: These data suggest that the presence of inflammation, lesion site, and biopsy technique modifies the reliability of oral lesion histologic diagnoses.

The effect of clinical information on the histopathologic diagnosis of oral epithelial dysplasia.

OBJECTIVES: The purpose of this study was to test the hypothesis that clinical information submitted with biopsy specimens helps pathologists be more consistent and accurate in diagnosing oral epithelial dysplasia. STUDY DESIGN: Each of six board-certified oral and maxillofacial pathologists examined the same set of 120 oral biopsies (involving diagnoses ranging from hyperkeratosis to severe epithelial dysplasia); they had examined these same biopsies in a previous study, but this time the clinical information was provided for each case. The examiner's diagnosis was compared to the sign-out diagnosis for each case. RESULTS: Rates of exact agreement with the sign-out diagnosis averaged 38.5%, and there was 85.4% agreement within one histologic grade. The rate of agreement in distinguishing epithelial dysplasia from no dysplasia was 71.4%. These results, when compared to those from a previous study in which the same examiners had evaluated the same slides but without clinical histories, represent a 2.5% to 20% decrease for exact agreement among the six pathologists, a 0% to 8.5% decrease for agreement within one histologic grade, and a 0% to 23.4% decrease for agreement regarding the presence or absence of epithelial dysplasia. CONCLUSIONS: When clinical information was used, accuracy and consistency among board-certified oral and maxillofacial pathologists in the diagnosis of oral epithelial dysplasia was not improved. In fact, there was a decrease in accuracy.

Oral exfoliative cytology: review of methods of assessment.

The use of oral exfoliative cytology in clinical practice declined due to the subjective nature of its interpretation and because there may be only a small number of abnormal cells identifiable in a smear. The more recent application of quantitative techniques, together with advances in immunocytochemistry, have refined the potential role of cytology, stimulating a reappraisal of its value in the diagnosis of oral cancer. This review considers the influence of the quantitative analysis of cytomorphology, DNA analysis and other tumour markers applied to oral exfoliative cytological samples. These studies indicate that oral cytology may provide an important adjunct in the assessment of the patient with a potentially cancerous oral lesion.

Intraexaminer and interexaminer reliability in the diagnosis of oral epithelial dysplasia.

OBJECTIVES: Pathologists differ in their definition of "dysplasia." This study was done to test the hypothesis that experienced oral pathologists are consistent in diagnosing epithelial dysplasia. STUDY DESIGN: Six board-certified oral pathologists examined 120 oral biopsies exhibiting simple hyperkeratosis to severe dysplasia. No clinical information was given, and presence of dysplasia was judged by histomorphology. Examiners' diagnoses were compared with sign-out diagnoses for each case. Months later, each examiner viewed 60 relabeled slides from the original 120. Each diagnosis was compared with the diagnosis in the first round. RESULTS: Exact agreement with the sign-out diagnosis averaged 50.5% (within one histologic grade 90.4%). Examiners agreed exactly with their own diagnoses 50.8% of the time (within one histologic grade 92.4%). Agreement distinguishing dysplasia from no dysplasia compared with original sign-out diagnosis was 81.5%. Agreement with themselves distinguishing dysplasia from no dysplasia was 80.3%. CONCLUSIONS: Accurate reproducible agreement among experienced board-certified oral pathologists diagnosing oral epithelial dysplasia is difficult to achieve.

Observer variability in the histologic assessment of oral premalignant lesions.

Histopathologic examination of oral leukoplakias has a major impact on the assessment of prognosis and treatment planning. We investigated the extent of agreement in grading epithelial dysplasia between pathologists with the same or different educational backgrounds. Two general pathologists and two oral pathologists were each given 100 sections of oral leukoplakia to grade from no dysplasia to carcinoma in-situ. The interobserver agreement rates were in the range of 49% to 69%. The calculated kappa values were in the range of 27% to 45%, showing poor to moderate agreement between the pathologists. When comparing the kappa values between the two pairs of pathologists with the same education, these values did not diverge from the general level of kappa values, indicating that the interobserver variability was due to individual differences rather than to educational background.