Controversies regarding oral lichen planus and lichenoid-dysplastic lesions.

Objective: Oral lichen planus (OLP) is an immune-mediated condition featuring chronic inflammation. The World Health Organization classifies OLP as potentially malignant, but it is believed that the malignant transformation of OLP occurs in lesions with both lichenoid and dysplastic features (LD). This review discusses the issues surrounding OLP and LD, including their malignancy, classification, and categorization, and whether lichenoid inflammation causes dysplastic changes in LD or vice versa. Methods: English full-text literature on OLP, LD and/or dysplasia was retrieved from PubMed, CINAHL, and Google Scholar. Results: Thirty-six publications including original research articles, reviews, meta-analyses, books, reports, letters, and editorials were selected for review. Discussion: Research suggests that OLP has malignant potential, although small, and that LD should not be disregarded, as dysplasia presenting with or without lichenoid features may develop into cancer. There is also disagreement over the classification and categorization of LD. Different terms have been used to classify these lesions, including lichenoid dysplasia, OLP with dysplasia, and dysplasia with lichenoid features. Moreover, in LD, it is not clear if dysplasia or lichenoid infiltration appears first, and if inflammation is a response to dysplasia or if dysplasia is a response to the persistent inflammation. The main limitation in the literature is the inconsistency and subjective nature of histological diagnoses, which can lead to interobserver and intraobserver variation, ultimately resulting in the inaccurate diagnosis of OLP and LD. Conclusion: Although further research is required to understand OLP and LD, both lesions should be considered potentially malignant and should not be disregarded.

Objectif: Le lichen plan buccal (LPB) est une pathologie auto-immune qui se présente sous la forme d'une inflammation chronique. Selon la classification de l'Organisation mondiale de la santé, le LPB est une pathologie potentiellement maligne. Toutefois, on soupçonne que la transformation maligne du LPB se produit dans des lésions présentant à la fois des caractéristiques lichénoïdes et dysplasiques (LD). Cet examen porte sur les questions relatives au LPB et aux LD, notamment leur malignité, leur classification et leur catégorisation, et pour savoir si l'inflammation du lichénoïde entraîne des changements dysplasiques des LD ou vice versa. Méthodes: On a utilisé le texte intégral de documents rédigés en anglais sur le LPB, les LD et la dysplasie issus de PubMed, de CINAHL et de Google Scholar. Résultats: Trente-six publications, notamment des articles sur des études originales, des revues, des méta-analyses, des livres, des rapports, des lettres et des éditoriaux, ont été sélectionnées aux fins d'examen. Discussion: Des études suggèrent que le LPB est potentiellement malin, bien que ce potentiel soit faible, et que les LD ne doivent pas être ignorés : en effet, une dysplasie peut évoluer en cancer, qu'elle présente des caractéristiques lichénoïdes ou non. On constate également un désaccord quant à la classification et à la catégorisation des LD. Différents termes ont été utilisés pour la classification de ces lésions, notamment « dysplasie lichénoïde ¼, « LPB dysplasique ¼ et « dysplasie à caractéristiques lichénoïdes ¼. De plus, dans le cas des LD, on ne sait pas avec certitude si la dysplasie ou l'infiltration lichénoïde apparaît en premier, ni si l'inflammation découle de la dysplasie ou si la dysplasie est une conséquence de l'inflammation persistante. La principale limite de la littérature est due aux incohérences et à la nature subjective des diagnostics histologiques, qui peut entraîner des variations d'un observateur à l'autre ou même avec un même observateur, ce qui entraîne à terme des diagnostics erronés de LPB et de LD. Conclusion: Bien que d'autres études soient nécessaires pour comprendre le LPB et les LD, les lésions de ces 2 catégories doivent être considérées comme potentiellement malignes et ne doivent pas être ignorées.

A critical influence of HIF-1 on MMP-9 and Galectin-3 in oral lichen planus.

OBJECTIVE: Oral lichen planus carries a risk for malignancy. The pathogenesis of the disease is mediated by various inflammatory mediators. Several mediators could be responsible for the oncogenic behavior in certain cases. Hypoxia-inducible factor-1a (HIF-1), and its possible correlation to Galactin-3 (Gal-3) and matrix metalloproteinase-9 (MMP-9) over expression represents an important indicator for malignant transformation. The investigation of these factors may present evidence-based information on malignant transformation of the disease. SUBJECTS AND METHODS: The study investigated the expression of HIF-1, Gla-3 and MMP-9 in tissue samples of OLP compared to control subjects of un-inflamed gingival overgrowth. 20 biospecimen were allocated in each group. RESULTS: Immunohistochemical findings of OLP showed immunoreactivity for Galectin 3, HIF1a and MMP-9 by most of the epithelial cells. There was a positive correlation between HIF1α and MMP-9, r = 0.9301 (P-value < 0.00001). A positive correlation was detected between Galectin 3 and MMP-9, r = 0.7292 (P-value = 0.000264) between Galectin 3 and HIF1α, r = 0.5893 (P-value = 0.006252). CONCLUSION: These findings confirm the hypothesis that the adaptive pathways to hypoxia as Gal 3 and MMP-9 expressions and their HIF-1 may play a crucial role in carcinogenesis of OLP.

Salivary and serum estrogen level assessment in oral lichen planus patients and its correlative analysis with OLP and stress.

Background: Lichen planus is a chronic inflammatory disease of the skin and mucous membrane with higher predilection seen in the female population. Oral lichen planus (OLP) has been associated with various etiological factors, such as stress, hormonal imbalance, and immunological variation. The purpose of this study was to assess serum and salivary estrogen (E2) levels in OLP patients and correlate them with stress levels. Objectives: This study aimed to evaluate serum and salivary estrogen levels in female patients with OLP, along with the assessment of stress and its correlation with estrogen levels. Methods: A total of 78 females, 39 clinically diagnosed with OLP and 39 healthy females, were included in the study as the case and control groups, respectively. 2 ml each of salivary and serum samples was obtained from each participant to measure the estrogen levels. Stress levels in the study group patients were assessed using the Depression Anxiety Stress Scale (DASS-21) and the Perceived Stress Scale (PSS). The nonparametric Mann-Whitney test was used for intergroup comparisons. Results: Significantly higher serum estrogen levels with higher DASS-21 and PSS scores were noted in patients with OLP. Overall, significant positive correlations were observed between salivary E2 and serum E2 (r = 0.361, P = 0.001). There was a positive correlation between salivary and serum E2 and DASS score (r = 0.410, P < 0.001, and r = 0.768, P < 0.001, respectively), serum/salivary E2 and PSS score (r = 0.745, P < 0.001, and r = 0.410, P < 0.001, respectively), and DASS score and PSS score (r = 0.878, P < 0.001). Conclusion: Estrogen can be used as a useful biomarker for OLP in the future. Salivary samples can prove to be an accurate and feasible alternative to serum estrogen level determination. We also suggest that OLP patients must be given supportive psychological treatment for improved life quality and disease management.

Lichen Planus of the Lip-Case Series and Review of the Literature.

Background and Objectives: Lichen planus of the lip (LPL) is a chronic inflammatory condition that resembles actinic cheilitis, discoid lupus erythematosus, graft-versus-host disease, and lichenoid reaction to dental materials or drugs. The purpose of this study was to conduct a literature review on lichen planus lip involvement and to report a retrospective observational study that characterises and explores the clinical, histopathological, and evolution of the lesions in a group of patients with unique involvement of LPL. Materials and Methods: Clinical data of patients diagnosed with LPL was retrieved from the medical charts of the patients referred to the Oral Pathology Department of the "Carol Davila" University of Medicine and Pharmacy. A concurrent electronic literature research was carried out using PubMed and Web of Science from 2003 to 2023. Results: Eleven patients diagnosed with unique LPL were analysed (male/female ratio was 1.75, mean age 63.64 years ± 12.52). All patients presented lesions of the lower lip; the clinical forms were atrophic (six cases) and erosive (five cases), and the histopathological exam confirmed the diagnosis. After topical treatment with corticosteroids, most of the patients had complete remission. The literature review revealed 24 studies (sixteen case reports and eight case series) which comprised 84 patients. Isolated lip involvement was reported in 17 studies, and five articles with concomitant oral lichen planus, while two articles did not mention this criterion. Conclusions: Our study brings new data on isolated lichen planus of the lip that primarily affects the lower lip with predominance in male patients. It was reported worldwide in patients between 22 and 75 years old. Topical corticosteroids were the main treatment prescribed and they usually brought remission of the lesions. Lichen planus of the lip is a challenging diagnosis for oral health practitioner providers as well as for dermatologists.

A Comparative Evaluation of Clinical Efficacy of Topical Amlexanox and Triamcinolone Acetonide in Oral Lichen Planus.

BACKGROUND: Oral lichen planus (OLP) is a chronic mucocutaneous disease affecting the general population, with its exact etiology remaining unknown. This condition is characterized by T-cell mediated autoimmunity wherein auto-cytotoxic CD8+ T cells precipitate basal cell apoptosis in the oral epithelium. Conventionally, corticosteroids have been the mainstay of treatment for OLP, necessitating the exploration of alternatives to mitigate long-term corticosteroid-related adverse effects. Amlexanox, a topical anti-inflammatory agent, impedes the synthesis and release of histamine, TNF-alpha, and leukotrienes from mast cells, neutrophils, and mononuclear cells, conceivably implicated in OLP pathogenesis. AIMS: The study aims to evaluate and compare the clinical efficacy of topical amlexanox and triamcinolone acetonide in the treatment of OLP. OBJECTIVES: The objectives of this study are (i) to evaluate the lesion size following the topical application of 5% amlexanox paste in the treatment of OLP, (ii) to evaluate the burning sensation of the patient based on the VAS score, and (iii) to compare and evaluate the clinical efficacy of 5% amlexanox with 0.1% triamcinolone acetonide in the treatment of OLP. METHODOLOGY: Forty patients clinically and histopathologically diagnosed with symptomatic OLP were randomly assigned into two groups, each comprising 20 patients. Group A was prescribed topical 5% amlexanox, while Group B received topical 0.1% triamcinolone acetonide with instructions to apply the drug at the site of the lesion intraorally thrice a day after food. The clinical improvement was evaluated using the Thongprasom scale, and the burning sensation was assessed using the visual analog scale (VAS) score weekly over four weeks. RESULTS: The study showed that there was a statistically significant reduction in the VAS score and size of lesion with each drug individually (p=0.000). There was a statistically significant difference in the mean values of VAS scores and size of the lesion between the first visit and fourth week, indicating a gradual reduction of the burning sensation and size of the lesion in both Group A and Group B, respectively. When both the groups were compared, there was no significant difference (p>0.05) in the reduction of burning sensation between Group A and Group B, indicating that amlexanox was as effective as triamcinolone in reducing the VAS score. However in terms of reduction of lesion size during the second week (p=0.022) and the third week (p=0.013), a statistically significant value was seen with a greater reduction in the size of the lesion in Group B compared to Group A. CONCLUSION: Given its anti-inflammatory properties and lower incidence of adverse effects relative to corticosteroids, amlexanox acts as a promising first-line therapeutic option for OLP. In cases of inadequate response, adjunctive therapies can be considered.

Clinical and mycological analysis of colonization by Candida spp. in oral leukoplakia and oral lichen planus.

OBJECTIVE: This study aims to analyze the prevalence of Candida spp. colonization in oral leukoplakia and oral lichen planus lesions, verify the influence of systemic and local factors, besides identify and determine the in vitro antifungal susceptibility profile of Candida species. MATERIALS AND METHODS: Samples were collected by swabbing from oral lesions and healthy mucosa and cultured on Sabouraud Dextrose and CHROMagar® Candida plates. Species identification was confirmed with MALDI-TOF MS analysis. RESULTS: Candida spp. was found in 36.8% of cases of oral leukoplakia and 18.2% of cases of oral lichen planus. Candida albicans was the only species found in oral lichen planus lesions (n = 2, 100%) and the most prevalent in oral leukoplakia (n = 5, 76.4%). Among the non-albicans Candida species found in oral leukoplakia were C. parapsilosis (n = 2, 25.5%) and C. tropicalis (n = 1, 14.1%). Candida isolates were susceptible to all antifungals tested. CONCLUSION: C. albicans was the most commonly found species in the studied lesions. No correlation was found between systemic and local factors with positive cases of oral lichen planus. However, smoking and alcohol consumption may be associated with positive cases of oral leukoplakia, especially the non-homogeneous clinical form. In addition, there is a possible predisposition to associated Candida colonization in cases of epithelial dysplasia found in oral leukoplakia. The antifungal medications tested showed excellent efficacy against isolates.

Expression of epithelial growth factor receptor as a protein marker in oral reticular and erosive lichen planus.

BACKGROUND: Oral lichen planus (OLP) is a chronic inflammatory mucosal disease that is classified as a premalignant condition. Epithelial growth factor receptor (EGFR) is associated with tumorigenesis and tumor progression and is overexpressed in several oral malignant disorders. Despite the association of EGFR overexpression with oral potentially malignant lesions, few studies have analyzed its expression in OLP, showing controversial results. This study aimed to compare the expression of EGFR as a protein marker in Reticular and Erosive OLP. METHODS: This descriptive-analytical cross-sectional was conducted on 15 paraffin blocks of reticular lichen planus lesions, 16 paraffin blocks of erosive OLP lesions, and 8 paraffin blocks of inflammatory fibrous hyperplasia lesions as the control group (39 in total). After immunohistochemical staining for EGFR, samples were simultaneously observed by two maxillofacial pathologist, and the percentage of stained cells, intensity of staining, pattern of staining, and the location of stained cells were obtained. RESULTS: The Mann-Whitney-U test showed that there was no significant difference in the mean percentage of stained cells between erosive OLP and reticular OLP (P-value = 0.213) and between reticular OLP and control group (P-value = 0.137), but there was a significant difference between erosive OLP and control group (P-value = 0.035). Fisher's exact test showed that there was no significant difference between the frequency distribution of staining patterns in three types of lesions (P-value = 0.90). Kruskal-Wallis test showed that there was no significant difference between the intensity of staining in the three groups (P-value = 0.19) and also there was no significant difference between the location of stained cells in different layers of the epithelium in the three groups (P-value = 0.90). CONCLUSIONS: The results of this study showed that in comparison of reticular OLP, erosive OLP, and the control group there was a significant difference just between erosive OLP and control group in the percentage of stained cells.

Regenerative medicine in the treatment of specific dermatologic disorders: a systematic review of randomized controlled clinical trials.

AIMS AND OBJECTIVES: The aim of this study is to systematically review randomized controlled clinical trials (RCTs) studying various types of regenerative medicine methods (such as platelet-rich plasma, stromal vascular fraction, cell therapy, conditioned media, etc.) in treating specific dermatologic diseases. Rejuvenation, scarring, wound healing, and other secondary conditions of skin damage were not investigated in this study. METHOD: Major databases, including PubMed, Scopus, and Web of Science, were meticulously searched for RCTs up to January 2024, focusing on regenerative medicine interventions for specific dermatologic disorders (such as androgenetic alopecia, vitiligo, alopecia areata, etc.). Key data extracted encompassed participant characteristics and sample sizes, types of regenerative therapy, treatment efficacy, and adverse events. RESULTS: In this systematic review, 64 studies involving a total of 2888 patients were examined. Women constituted 44.8% of the study population, while men made up 55.2% of the participants, with an average age of 27.64 years. The most frequently studied skin diseases were androgenetic alopecia (AGA) (45.3%) and vitiligo (31.2%). The most common regenerative methods investigated for these diseases were PRP and the transplantation of autologous epidermal melanocyte/keratinocyte cells, respectively. Studies reported up to 68.4% improvement in AGA and up to 71% improvement in vitiligo. Other diseases included in the review were alopecia areata, melasma, lichen sclerosus et atrophicus (LSA), inflammatory acne vulgaris, chronic telogen effluvium, erosive oral lichen planus, and dystrophic epidermolysis bullosa. Regenerative medicine was found to be an effective treatment option in all of these studies, along with other methods. The regenerative medicine techniques investigated in this study comprised the transplantation of autologous epidermal melanocyte/keratinocyte cells, isolated melanocyte transplantation, cell transplantation from hair follicle origins, melanocyte-keratinocyte suspension in PRP, conditioned media injection, a combination of PRP and basic fibroblast growth factor, intravenous injection of mesenchymal stem cells, concentrated growth factor, stromal vascular fraction (SVF), a combination of PRP and SVF, and preserving hair grafts in PRP. CONCLUSION: Regenerative medicine holds promise as a treatment for specific dermatologic disorders. To validate our findings, it is recommended to conduct numerous clinical trials focusing on various skin conditions. In our study, we did not explore secondary skin lesions like scars or ulcers. Therefore, assessing the effectiveness of this treatment method for addressing these conditions would necessitate a separate study.

Oral Lesions of Immune-Mediated and Autoimmune Diseases: A 12-year Experience at a Single Brazilian Referral Center.

BACKGROUND: Oral lesions of immune-mediated and autoimmune diseases have been well-documented, but studies from Brazil are limited. The varied spectrum of oral lesions within this demographic group poses challenges to clinicians, particularly when they occur in isolation. This study aimed to evaluate the occurrence, clinical characteristics, and management of patients with oral lesions of immune-mediated and autoimmune diseases at a single center in Brazil. METHODS: A retrospective cross-sectional study was conducted from 2010 to 2022. Clinicodemographic data, histopathological features, and treatment modalities were analyzed descriptively and analytically. RESULTS: Of the 3,790 oral and maxillofacial lesions diagnosed, 160 (4.2%) were confirmed as immune-mediated or autoimmune diseases. The population surveyed predominantly consisted of women (73.7%), with a mean age of 60.2 years. Oral lichen planus (51.3%), mucous membrane pemphigoid (MMP) (23.7%), and pemphigus vulgaris (PV) (19.4%) were the most prevalent lesions. The buccal mucosa (59.4%) was predominantly affected, with pain reported in 46.2% of cases, notably in individuals with PV and MMP. The average time to disease stabilization post-local and/or systemic corticosteroid therapy was 15.8 months for systemic lupus erythematosus, 8.7 months for MMP, and 6.5 months for PV. CONCLUSION: Although oral lesions related to immune-mediated and autoimmune diseases are uncommon, their diverse clinicopathological aspects require multidisciplinary management.

Case Report: Recalcitrant oral lichen planus involving bilaterally buccal mucosae treated with a combination of photodynamic and photobiomodulation therapies.

Background: Managing recalcitrant oral lichen planus (OLP) can be challenging. Laser therapy has been suggested as an alternative to corticosteroids for treatment. Photodynamic therapy (PDT) is a non-invasive technique that enables the removal of lesions without surgery. Photobiomodulation therapy (PBMT) can promote healing and recovery of the lesions. Case presentation: The objective was to treat unresponsive bilateral OLP of the whole buccal mucosae with a combination of PDT and PBMT. Results: A 43-year-old Thai male presented with the severe painful reticular type of OLP of bilateral buccal mucosae involving upper and lower vestibular areas. The lesions were not remitted with either prednisolone systemic steroids or fluocinolone topical corticosteroids. After undergoing ten sessions of PDT with 10% 5-Aminolevulinic acid (5-ALA) in the form of thermoplastic gel and a 635 nm diode laser at 100 to 400 mW with an energy density of 20 to 30 J/cm 2 in continuous wave mode, combined with five interim-sessions of PBMT using a 635 nm diode laser at 200 to 300 mW with an energy density of 6 to 10 J/cm 2 in continuous wave, the patient reported relief of burning sensation beside remission of lesions without any complications. Conclusion: The wide-spreading recalcitrant OLP with burning sensation can be managed by combining PDT and PBMT.

Efficacy and safety of topical clobetasol propionate in comparison with alternative treatments in oral lichen planus: an updated systematic review and meta-analysis.

Background: Oral lichen planus (OLP) is a relatively common chronic T cell-mediated disease characterized by pain and inflammation. Clobetasol propionate (CLO) is the first-line drug in the treatment of OLP. The meta-analysis aimed to evaluate the efficacy and safety of CLO for treating patients with OLP. Methods: PubMed, Embase and Web of Science were systematically searched from the database inception date up to August 2023. There were no restrictions on language or date of publication. The outcomes of our interest were as follows: improvement of clinical signs and/or symptoms, total lesion size, relapse and adverse events. Results: A total of 17 RCTs evaluating the effects of CLO were included in this study. The results revealed no significant difference in the clinical score (WMD = 0.14, 95% CI: -0.39, 0.66; p = 0.609) and pain score (WMD = 0.17, 95% CI: -0.44, 0.79; p = 0.582) between CLO and other treatments. However, clinical resolution (RR = 1.61, 95% CI: 1.17, 2.22; p = 0.003) and symptoms improvement (RR = 1.80, 95% CI: 1.17, 2.77; p = 0.008) were significantly different between CLO and other treatments. Moreover, there was a significant reduction in the total lesion size with CLO treatment (WMD = -0.58, 95% CI: -1.03, -0.13; p = 0.011). In addition, CLO showed no statistical incidence of adverse events (RR = 1.46, 95% CI: 0.86, 2.50; p = 0.161) and relapse (RR = 1.56, 95% CI: 0.66, 3.71; p = 0.314) than other therapies. Conclusion: This systematic review and meta-analysis of 17 randomized clinical trials supported the long-term application of CLO as an effective regimen in OLP patients.

A New Scoring System of Oral Lichen Planus.

Lichen planus (LP) is a chronic, immune-mediated mucocutaneous disorder increasingly becoming common in the general population with female predominance. Clinically, there are different forms of lichen planus with the presence of the main characteristic feature of Wickham striae. Literature, to date, is abundant with various scoring systems of oral lichen planus, and among them, the most commonly followed scoring system was the one proposed by the Thongprasom system because of its simplicity and ease of application. Aim: The aim of the present study is to critically review all the disease scoring systems on oral lichen planus (OLP) that have been reported in the literature during the past decades. A systematic literature search was performed using PUBMED, MEDLINE, EMBASE, and COCHRANE Library with language restriction to English. The search was carried out incorporating the published literature from 1980 to 2020 using the MeSH (medical subject heading) terms. A literature search was done using keywords: Staging, Grading, Oral lichen planus, Diagnostic, and Therapeutic. Out of 25 publications, related to search strategy, 22 full articles, which were related to the disease scoring system for oral lichen planus, were acquired for further inspection. Out of the 22 articles, 15 articles met the inclusion criteria. The data was collected and a brief summary of the studies regarding the different disease scoring systems for oral lichen planus was explained. Taking into consideration, the parameters were not included in the previous disease scoring system. A new proposal encompassing a scoring system for oral lichen planus considering the missing parameters along with an amalgamation of histopathological criteria of dysplasia is presented. It also proposes to grade and stage the lesions and recommend appropriate therapy for each of such lesions.

Keratinocytes stimulate MAIT cells to produce granzyme B via MR1 and cytokines in oral lichen planus.

OBJECTIVE: Oral lichen planus (OLP) is a chronic inflammatory disease characterized by a dense T-cell infiltration and the degeneration of basal keratinocytes. The potential functions of mucosal associated invariant T (MAIT) cells in OLP have been analyzed in our previous study. Keratinocytes under proinflammatory conditions have been demonstrated to activate T cells. This study was aimed to investigate how keratinocytes stimulate MAIT cells in OLP, and to explore the role of activated MAIT cells on keratinocytes. METHODS AND RESULTS: Increased MAIT cells and higher activation marker CD69 were detected in OLP lesions by flow cytometry. The enhanced expression of MHC class I-like molecule (MR1) required for MAIT cell activation in the epithelial layer of OLP lesions was determined by immunohistochemistry. Keratinocytes treated by 5-A-RU prodrug and lipopolysaccharide, respectively, exhibited higher expression of MR1 and secretion of IL-18. In direct coculture systems consisting of keratinocytes and peripheral blood mononuclear cells, both 5-A-RU prodrug-pretreated keratinocytes and lipopolysaccharide-pretreated keratinocytes activated MAIT cells to secrete granzyme B, contributing to elevated keratinocyte apoptosis. CONCLUSIONS: Keratinocytes were capable to activate MAIT cells via MR1 and cytokines in OLP, and granzyme B produced by activated MAIT cells intensified keratinocyte apoptosis, engaging in the pathogenesis of OLP.

Advancements in diagnosing oral potentially malignant disorders: leveraging Vision transformers for multi-class detection.

OBJECTIVES: Diagnosing oral potentially malignant disorders (OPMD) is critical to prevent oral cancer. This study aims to automatically detect and classify the most common pre-malignant oral lesions, such as leukoplakia and oral lichen planus (OLP), and distinguish them from oral squamous cell carcinomas (OSCC) and healthy oral mucosa on clinical photographs using vision transformers. METHODS: 4,161 photographs of healthy mucosa, leukoplakia, OLP, and OSCC were included. Findings were annotated pixel-wise and reviewed by three clinicians. The photographs were divided into 3,337 for training and validation and 824 for testing. The training and validation images were further divided into five folds with stratification. A Mask R-CNN with a Swin Transformer was trained five times with cross-validation, and the held-out test split was used to evaluate the model performance. The precision, F1-score, sensitivity, specificity, and accuracy were calculated. The area under the receiver operating characteristics curve (AUC) and the confusion matrix of the most effective model were presented. RESULTS: The detection of OSCC with the employed model yielded an F1 of 0.852 and AUC of 0.974. The detection of OLP had an F1 of 0.825 and AUC of 0.948. For leukoplakia the F1 was 0.796 and the AUC was 0.938. CONCLUSIONS: OSCC were effectively detected with the employed model, whereas the detection of OLP and leukoplakia was moderately effective. CLINICAL RELEVANCE: Oral cancer is often detected in advanced stages. The demonstrated technology may support the detection and observation of OPMD to lower the disease burden and identify malignant oral cavity lesions earlier.

Potential role of salivary lactic acid bacteria in pathogenesis of oral lichen planus.

BACKGROUND: Emerging evidence emphasized the role of oral microbiome in oral lichen planus (OLP). To date, no dominant pathogenic bacteria have been identified consistently. It is noteworthy that a decreased abundance of Streptococcus, a member of lactic acid bacteria (LAB) in OLP patients has been commonly reported, indicating its possible effect on OLP. This study aims to investigate the composition of LAB genera in OLP patients by high-throughput sequencing, and to explore the possible relationship between them. METHODS: We collected saliva samples from patients with OLP (n = 21) and healthy controls (n = 22) and performed 16 S rRNA gene high-throughput sequencing. In addition, the abundance of LAB genera was comprehensively analyzed and compared between OLP and HC group. To verify the expression of Lactococcus lactis, real time PCR was conducted in buccal mucosa swab from another 14 patients with OLP and 10 HC. Furthermore, the correlation was conducted between clinical severity of OLP and LAB. RESULTS: OLP and HC groups showed similar community richness and diversity. The members of LAB, Lactococcus and Lactococcus lactis significantly decreased in saliva of OLP cases and negatively associated with OLP severity. In addition, Lactococcus and Lactococcus lactis showed negative relationship with Fusobacterium and Aggregatibacter, which were considered as potential pathogens of OLP. Similarly, compared with healthy controls, the amount of Lactococcus lactis in mucosa lesion of OLP patients was significantly decreased. CONCLUSIONS: A lower amount of Lactococcus at genus level, Lactococcus lactis at species level was observed in OLP cases and associated with disease severity. Further studies to verify the relationship between LAB and OLP, as well as to explore the precise mechanism is needed.

CD4+CD8αα+ is the dominant phenotype of intraepithelial lymphocytes and regulated by ThPOK and Runx3 in Oral lichen planus.

BACKGROUND: Oral lichen planus (OLP) is a common T cell-mediated oral mucosal immune inflammatory disease. Intraepithelial lymphocytes (IELs) are a unique subset of T cells that play an important role in regulating immune response. This study aims to investigate the phenotype and the differentiation mechanism of IELs in OLP. METHODS: The expression of CD4, CD8α, CD8ß, T-helper-inducing POZ/Krueppel-like factor (ThPOK), and RUNX family transcription factor 3 (Runx3) in the epithelium and peripheral blood mononuclear cells (PBMCs) of OLP was determined by immunofluorescence and immunohistochemistry. Then, the correlations among them were analyzed. Naïve CD4+ T cells were sorted from blood of OLP patients and stimulated with retinoic acid (RA) and transforming growth factor-ß1 (TGF-ß1). Then the expression of CD4, CD8α, CD8ß, ThPOK, and Runx3 was investigated by immunocytochemistry. RESULTS: CD8α expression and CD8αα+ cells were upregulated in the epithelium of OLP, whereas they were downregulated in PBMCs of OLP. CD8ß was not expressed in the epithelium of OLP. CD4, CD8α, and Runx3 expression and CD4+CD8α+ cells were increased, whereas ThPOK expression was decreased in the epithelium of OLP. CD8α expression was positively correlated with Runx3 expression, whereas ThPOK expression was negatively correlated with Runx3 expression. After RA and TGF-ß1 stimulation, CD8α and Runx3 expression was upregulated, and ThPOK expression was downregulated in naïve CD4+ T cells. CONCLUSION: CD4+CD8αα+ IELs may be the dominant phenotype of IELs in OLP, and the differentiation of CD4+CD8αα+ IELs in OLP is negatively regulated by ThPOK and positively regulated by Runx3.

The effect of antiresorptive therapy on the prevalence and severity of oral lichen planus: a retrospective study.

BACKGROUND: Antiresorptive therapy (AR) disrupts osseous homeostasis and can induce direct irritation over the gastrointestinal mucosa; however, its possible erosive effects on the oral epithelium have not been totally described. Among the most frequent oral erosive lesions, oral lichen planus (OLP) frequently presents as painful mucosal ulcerations, arising from basal membrane inflammatory damage. Thus, the aim of this retrospective study was to describe the association between AR and the incidence of OLP. METHODS: This case-control study included data from 148 patients (17 patients undergoing AR therapy (AR group) / 131 without AR therapy (Control group)). Each patient record was systematically processed and the association between AR drugs and OLP clinical characteristics within both groups was assessed. RESULTS: The erosive form of OLP was significantly more frequent in the AR group than in the Control group (p = 0.029). Indeed, the AR treatment using alendronic acid (41.2%) was the most frequently reported. Additionally, the erosive form of OLP showed the strongest association with pain and burning sensation among the OLP types (p < 0.050). However, disease worsening and AR consumption were not significantly associated (p = 0.150). CONCLUSIONS: Patients under AR therapy show more clinical symptoms associated to the erosive type of OLP. Regardless of the AR therapy, the erosive type of OLP is associated with more severe symptoms.

PA28γ induces dendritic cell maturation and activates T-cell immune responses in oral lichen planus.

Oral lichen planus (OLP) is a common chronic inflammatory disease of the oral mucosa, the mechanism of its inflammatory progression has not yet been fully elucidated. PA28γ plays a significant role in a variety of immune-related diseases. However, the exact role of PA28γ in the pathogenesis of OLP remains unclear. Here, we demonstrated that PA28γ is overexpressed in epithelial cells and inflammatory cells of OLP tissues but has no significant relationship with OLP subtypes. Functionally, keratinocytes with high PA28γ expression could induce dendritic cell (DC) maturation and promote the T-cell differentiation into Th1 cells in response to the immune response. In addition, we found that a high level of PA28γ expression is associated with high numbers of infiltrating mature DCs and activated T-cells in OLP tissues. Mechanistically, keratinocytes with high PA28γ expression could promote the secretion of C-C motif chemokine (CCL)5, blocking CCL5 or/and its receptor CD44 could inhibit the induction of T-cell differentiation by keratinocytes with high PA28γ expression. In conclusion, we reveal that keratinocytes with high expression of PA28γ in OLP can induce DC maturation and promote T-cell differentiation through the CCL5-CD44 pathway, providing previously unidentified mechanistic insights into the mechanism of inflammatory progression in OLP.

The relationship between clinical symptoms of oral lichen planus and quality of life related to oral health.

INTRODUCTION: Oral Lichen Planus (OLP) is a chronic and relatively common mucocutaneous disease that often affects the oral mucosa. Although, OLP is generally not life-threatening, its consequences can significantly impact the quality of life in physical, psychological, and social aspects. Therefore, the aim of this research is to investigate the relationship between clinical symptoms of OLP and oral health-related quality of life in patients using the OHIP-14 (Oral Health Impact Profile-14) questionnaire. MATERIALS AND METHODS: This descriptive-analytical study has a cross-sectional design, with case-control comparison. In this study, 56 individuals were examined as cases, and 68 individuals were included as controls. After recording demographic characteristics and clinical features by reviewing patients' records, the OHIP-14 questionnaire including clinical severity of lesions assessed using the Thongprasom scoring system, and pain assessed by the Visual Analog Scale (VAS) were completed. The ADD (Additive) and SC (Simple Count) methods were used for scoring, and data analysis was performed using the T-test, Mann-Whitney U test, Chi-Square, Spearman's Correlation Coefficient, and SPSS 24. RESULTS: Nearly all patients (50 individuals, 89.3%) reported having pain, although the average pain intensity was mostly mild. This disease has affected the quality of life in 82% of the patients (46 individuals). The patient group, in comparison to the control group, significantly expressed a lower quality of life in terms of functional limitations and physical disability. There was a statistically significant positive correlation between clinical symptoms of OLP, gender, location (palate), and clinical presentation type (erosive, reticular, and bullous) of OLP lesions with OHIP-14 scores, although the number or bilaterality of lesions and patient age did not have any significant correlation with pain or OHIP scores. CONCLUSION: It appears that certain aspects of oral health-related quality of life decrease in patients with OLP, and that of the OLP patient group is significantly lower in terms of functional limitations and physical disability compared to the control group. Additionally, there was a significant correlation between clinical symptoms of OLP and pain as well as OHIP scores.

Animal models to study the pathogenesis and novel therapeutics of oral lichen planus.

Oral lichen planus (OLP) is a prevalent oral mucosal disease characterized by an unknown etiology and a complex pathogenesis. Patients with OLP endure a chronic course marked by alternating non-erosive and erosive lesions, with no definitive cure currently available. Particularly challenging is the treatment of recalcitrant erosive OLP, highlighting an urgent need for therapies targeting specific pathogenic pathways. In diseases like OLP, where the etiopathogenesis is intricate and elusive, animal models are indispensable for hypothesis testing and elucidating disease mechanisms. To date, only three animal models for oral lichenoid lesions have been reported in the literature. This Perspective paper evaluates these existing models, along with a novel OLP mouse model introduced at the 3rd International Conference on Oral Mucosal Immunity and Microbiome. The validity of these models is critically assessed, and their potential future applications in advancing our understanding of OLP are discussed.