T-cell-mediated oral mucocutaneous inflammatory conditions, including oral lichen planus, are common, but development of new treatments aimed at relieving symptoms and controlling oral lichen planus progression is hampered by the lack of experimental models. In this study, we developed a tissue-engineered oral mucosal equivalent containing polarized T-cells to replicate oral lichen planus pathogenesis. Peripheral blood CD4+ and CD8+ T-cells were isolated, activated, and polarized into T helper 1 and cytotoxic T cells. Oral mucosal equivalents were constructed by culturing oral keratinocytes on an oral fibroblast-populated hydrogel to produce a stratified squamous epithelium. Oral mucosal equivalent stimulated with IFN-γ and TNF-α or medium from T helper 1 cells caused increased secretion of inflammatory cytokines and chemokines. A model of T-cell-mediated inflammatory disease was developed by combining oral mucosal equivalent on top of a T helper 1 and cytotoxic T-cell-containing hydrogel, followed by epithelial stimulation with IFN-γ and TNF-α. T-cell recruitment toward the epithelium was associated with increased secretion of T-cell chemoattractants CCL5, CXCL9, and CXCL10. Histological assessment showed tissue damage associated with cleaved caspase-3 and altered laminin-5 expression. Treatment with inhibitors directed against Jak, KCa3.1 channels, or clobetasol in solution and through a mucoadhesive patch prevented cytokine and chemokine release and tissue damage. This disease model has potential to probe for mechanisms of pathogenesis or as a test platform for novel therapeutics or treatment modalities.

Oral lichen planus (OLP) and oral lichenoid lesions (OLL) are considered potentially malignant oral disorders, presenting with similar clinical and histopathological manifestations that make differential diagnosis difficult and reinforce the need for new techniques for their evaluation.

This study aimed to compare the histomorphometric characteristics of OLP and OLL.

This retrospective cross-sectional study was based on 30 histological sections of incisional biopsies of OLP and OLL stained with hematoxylin-eosin for the analysis of morphological parameters, such as keratosis, acanthosis, inflammatory infiltrate band, eosinophilic band, degeneration of the basal layer, involvement of the epithelium-chorion interface, and degree of subepithelial inflammatory infiltrate; and morphometric parameters, such as keratin thickness, distance from the basal layer to the epithelial surface, and thickness of the inflammatory infiltrate band. Chi-square and Fisher's exact tests were used to compare categorical variables and injury types. The t-test was used to compare morphometric variables between the two types of injury.

There was no significant association between the type of lesion and the clinical characteristics of the patients (p > 0.05). The degree of dysplasia, used as an inclusion criterion, was associated with lesion type (p = 0.0003). There were no significant differences between the morphometric variables evaluated for the two types of lesions (p > 0.05).

Based on the methodology used and the sample established for this study, there were clinical and histomorphometric similarities between OLP and OLL. This justifies further discussion on whether these lesions are a spectrum of presentations of the same condition or truly distinct conditions.

The formation mechanism of OLP is very complicated, and its treatment has always been a difficult problem. This study was to explore the feasibility of pulsed Er: YAG laser in the treatment of erosive OLP by comparing its effect with that of Triamcinolone Acetonide ointment(TA) of OLP, in order to provide new ideas for the clinical treatment of erosive OLP. Forty patients who were clinically and histopathologically diagnosed as OLP at the Department of Periodontics and Oral Mucosa Disease of Dalian Stomatological Hospital were selected, all lesions accompanied by erosion. The included patients were randomly divided into two groups: Er: YAG group and TA group, with 20 cases in each group. The visual analogue scale (VAS), mean lesion area, clinical sign score, and function score in both groups were evaluated at baseline, 1 week, 2 weeks, 1 month and 3 months after treatment, and the recurrence rate of cured patients in both groups was evaluated at 3 months after treatment. Er: YAG laser was superior to TA in relieving pain at 1 week(1.50 ± 0.946 vs. 2.10 ± 0.912, P < 0.05) and improving function at all stages(P < 0.05). But TA was superior to the pulsed Er: YAG laser in promoting the healing of erosive lesions at 2 weeks(0.07 ± 0.223 vs. 0.31 ± 0.549, P < 0.05). There was no significant difference in recurrence between the two groups(P > 0.05). There is no significant difference between pulsed Er: YAG laser and TA in the treatment of erosive OLP. The use of pulsed Er: YAG laser represents a viable and effective therapeutic option for erosive OLP.

This study evaluates the efficacy and safety of High-Intensity Laser Therapy (HILT) and Photobiomodulation (PBM) in treating Oral Lichen Planus (OLP), and explores optimal PBM parameter settings. A search of PubMed, Embase, Cochrane Library, Web of Science, CNKI, and SinoMed was conducted for randomized controlled trials (RCTs) on laser therapy for OLP up to October 30, 2024. Study quality was assessed using the Cochrane risk of bias tool and the Jadad score. Eighteen studies were identified, with 16 involving 742 participants included in the meta-analysis. Eleven studies compared PBM with topical corticosteroids (TCS), and five compared HILT with TCS. HILT provided superior pain relief compared to TCS (SMD = -0.51, 95% CI [-0.79,-0.23]), while PBM showed comparable outcomes (SMD = -0.41, 95% CI [-0.87, 0.04]). PBM was more effective at pain relief with total energy density below 120 J/cm2. Both HILT and PBM reduced recurrence rates (RR = 0.33,95%CI [0.15,0.73]; RR = 0.43, 95% CI [0.25, 0.74]) and improved cure rates (RR = 1.44, 95% CI [1.01, 2.06]; RR = 1.47, 95% CI [1.05, 2.05]). PBM had no adverse reactions, while HILT and TCS had associated adverse events. HILT and PBM may be considered effective alternatives to TCS. For PBM treatment of OLP, a total energy density below 120 J/cm2 is advisable. Further large-scale studies are required to confirm these findings and refine laser parameters.

Probiotics are live microorganisms consisting of many bacterial species that have immunoregulatory functions. The effectiveness of probiotic administration in conjunction with topical corticosteroid application in oral lichen planus (OLP) treatment was evaluated.

Sixty OLP patients were enrolled in this study and divided into two groups. Group 1 (Probiotics' group): probiotic capsules were administered twice daily, for 4 weeks in addition to topical clobetasol propionate application 0.05% four times daily. Group 2 (Control group): topical clobetasol propionate 0.05% was applied 4 times daily for 4 weeks. Thongprasom criteria, numerical rating scale and candidal load were evaluated.

Significant reduction in the numerical rating scale as well as Thongprasom scale in the probiotic group when compared to the control group, after 2 and 4 weeks, and more significant reduction was observed after 2 weeks. No difference in the reduction of the candidal load was observed between the two groups, nevertheless, no topical antifungal was used in the intervention group.

Systemic administration of probiotics as a supplementary treatment with topical corticosteroid was effective regarding the reduction of; pain, Thongprasom scales, and candidal load. However, the effectiveness was more evident after 2 weeks when compared to 4 weeks resulting in: more rapid relief of symptoms, improving quality of life, in addition to their antifungal properties.

The current study was registered in clinicaltrials.gov (ID: NCT04383236) 6-11-2023.

This study investigates the proteomic profiles of oral epithelial dysplasia with lichenoid features (OEDwithLF) and evaluates its relevance as a histopathological feature for lichenoid mucositis (LM) through differential proteomic characterization.

SWATH-MS proteomic profiling was conducted on FFPE samples from 6 OEDwithLF, 5 OED cases without associated lymphocytic infiltration, and 5 LM cases. Protein expression levels were quantified and compared. In silico analysis examined the biological and molecular functions of dysregulated proteins.

A total of 460 proteins were identified. Unsupervised clustering revealed significant differences between LM and OEDwithLF, with fewer differences observed between OEDwithLF and OED. Bioinformatic analysis indicated dysregulated proteins are involved in nucleic acid binding, ribosome function, and developmental biology. Key potential biomarkers include KRT17, LYSC, CAL5, and CRNN.

The proteomic profile of OEDwithLF is similar to OED without associated lymphocytic infiltration, but significantly different from LM. OED is relevant in lichenoid tissues, and its proteomic changes can be detected. Although OED may coexist with interface mucositis, it is not a defining feature of LM. This challenges the exclusion of epithelial dysplasia from lichenoid diagnoses. Based on this hypothesis-generating study, further investigation is warranted.

Desquamative gingivitis is an immunological chronic disease that is considered precancerous and has the potential to develop into squamous cell carcinoma. Carcinoembryonic antigen (CEA), a common tumor marker, increases in many cancers. The present study compared salivary CEA levels in desquamative gingivitis before and after topical corticosteroid therapy.

This case‒control study was conducted in the Department of Oral and Maxillofacial Medicine, Tabriz Faculty of Dentistry. Twenty patients with desquamative gingivitis in oral lichen planus (OLP) background were selected as the case group, with 20 healthy individuals as the control group. Desquamative gingivitis lesions were confirmed with biopsies. Salivary samples were obtained from both groups. Second, salivary samples were collected from the case group after a course of topical corticosteroid therapy. Salivary CEA levels were measured by a monobind kit using the ELISA method. Independent and paired t-tests were used to analyze the data in SPSS 17. P<0.05 was considered statistically significant.

Before treatment, CEA levels were significantly higher in the case group (174.06±95.55) than in the control group (55.66±41.26 ng/mL) (P<0.001). Salivary CEA levels in the case group decreased significantly after the treatment (96.77±66.25 ng/mL) compared to before treatment (174.06±95.55 ng/mL) (P<0.001).

This study demonstrated that CEA levels significantly decreased in patients with desquamative gingivitis associated with oral lichenoid reaction after receiving topical corticosteroid therapy.

This study aimed to explore the disparities in PD-1 and PD-L1 expression among oral squamous cell carcinomas (OSCCs) in individuals categorized as never-smokers/never-drinkers versus smokers/drinkers.

Immunohistochemical staining for PD-1 and PD-L1, along with PDCD1LG2/cen9 dual color probe analysis, was conducted on 130 OSCC specimens from both smoker/drinker and never-smoker/never-drinker cohorts. Associations between smoking/drinking status, clinicopathologic data, immunohistochemical antibody expression, fluorescence in situ hybridization, and survival outcomes were assessed.

OSCC in never-smokers/never-drinkers exhibited significantly elevated PD-1 expression (p = 0.003), increased PD-L1-TPS expression (p = 0.044), and elevated PD-L1-CPS expression (p < 0.001). High PD-L1-ICS expression was more prevalent in never-smokers (p = 0.042). Moreover, never-smokers and never-drinkers demonstrated augmented PD-L1 gene copy numbers (p = 0.081 and p = 0.054, respectively). Increased PD-L1 gene copy number, particularly amplification, correlated with PD-L1-TPS (p = 0.039 and p < 0.001). Conversely, PD-L1 gene copy loss was associated with negative PD-L1-CPS (p = 0.023). Notably, positive PD-L1-CPS was significantly linked with improved overall survival (p = 0.023).

OSCC arising in never-smokers/never-drinkers exhibit heightened PD-1/PD-L1 signaling, suggesting potential efficacy of immune checkpoint therapy in this subgroup of tumors.

Background: Oral lichen planus (OLP) is a chronic autoimmune disease of the oral mucosa, classified among potentially malignant oral disorders (OPMDs). It is characterized by keratinocyte apoptosis and persistent inflammation. Standard treatments involve topical corticosteroids administered via mouthwashes, gels, or ointments, but these require frequent application, have limited retention, and may cause side effects. To address these limitations, this study aimed to develop an innovative dexamethasone delivery system targeting the oral cavity, based on poly(lactic acid) (PLA) fibers coated with chitosan (CS) and poly(lactic-co-glycolic acid) (PLGA) nanoparticles. Methods: CS-coated PLA fibers were characterized for their mucoadhesive and cytocompatibility properties, while PLGA nanoparticles were analyzed for size, shape, encapsulation efficiency, cellular uptake, drug release efficiency, and cytocompatibility. Results: Both polymers demonstrated cytocompatibility, and chitosan-coated PLA fibers exhibited mucoadhesive properties. PLGA nanoparticles were effectively internalized by the cells and successfully released the drug into the cytoplasm. The combination of CS-coated PLA fibers and PLGA nanoparticles provided dual benefits: mucoadhesion and efficient cellular uptake, even under conditions simulating salivation. Conclusions: These findings highlight the potential of the proposed system to improve mucoadhesive drug delivery. Further optimization is needed to enhance patient compliance and therapeutic efficacy.

To examine the impact of fluocinonide 0.05% gel formulation for the topical treatment of oral lichen planus (OLP).

Through an RCT design, 47 patients with OLP were randomly allocated for topical OLP treatment with fluocinonide 0.05% (n = 23) or placebo (n = 24). Patients were examined for OLP symptoms, signs, disease severity, and extension score changes over 6-month follow-up.

After 6 months, in comparison with placebo, patients treated with fluocinonide experienced a significant reduction of OLP symptoms (p = 0.024), signs (p = 0.014), and OLP extension score (p = 0.028). The two-way ANOVA estimation models revealed that treatment with fluocinonide determined, at 6 months, a positive significant effect on the reduced OLP signs (p = 0.017), OLP symptoms (p = 0.026), and OLP extension score (p = 0.028). The multivariate regression analysis highlighted that anxiety, stress, and depression were significant predictors of every analyzed OLP outcome (p < 0.05 for each parameter) and that patients who had baseline anxiety, depression, and stress gained more benefits from fluocinonide at 6-month follow-up.

Topical fluocinonide 0.05% was more efficacious compared to placebo in reducing OLP outcomes at 6-month follow-up. Anxiety, depression, and stress were significant predictors of OLP outcomes and positively impacted the treatment with fluocinonide at 6 months.

To compare the demographic and clinical profiles of oral lichen planus (OLP) and oral lichenoid lesions (OLL) diagnosed at a reference center in Southern Brazil from 2010 to 2019.

This retrospective study included 117 cases of suspected OLP submitted for biopsy. Investigated variables comprised sociodemographic profiles, medical history, harmful habits, clinical characteristics, and histopathological features. Categorical and numerical variables were analyzed using chi-square and Mann-Whitney tests (p < 0.01), respectively.

Applying strict diagnostic criteria, 29% (n = 34) of cases were classified as OLP and 71% (n = 83) as OLL. OLP cases had mainly multifocal manifestations (82.4%), exhibiting a reticular pattern (100%) and primarily occurring on the buccal mucosa (94.1%). Conversely, OLL cases presented both unilateral (48.2%) and multifocal (51.8%) distributions, with a predominantly atrophic-erosive pattern (77.1%) and higher occurrence on the buccal mucosa (69.9%) and tongue (48.2%). OLL patients reported a higher frequency of systemic disorders and medication use (p < 0.01). Hypertension was the most prevalent condition, leading to the frequent use of cardiovascular medications. Two OLL cases without initial dysplasia underwent malignant transformation.

Patient profiles and clinical manifestations of the entities were similar, highlighting the utility of a differential diagnosis, particularly given the apparent association between malignant transformation and OLL cases.

Understanding the clinical course and malignant transformation rate of oral potentially malignant disorders (OPMDs)-including oral leukoplakia, oral erythroplakia, oral submucous fibrosis, and oral lichen planus-is crucial for early detection and improved survival rates in patients with oral cancer.

To evaluate the progression of oral cancer from OPMDs using a large US electronic medical database.

This retrospective cohort study used data from the University of California, San Francisco's PatientExploreR database between January 1973 and March 2024. Patients with oral leukoplakia, oral erythroplakia, oral submucous fibrosis, and oral lichen planus were identified using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, codes and keywords. Demographics, tobacco and alcohol use, HIV status, and other known risk factors for oral cancer were recorded to identify factors associated with malignant transformation. Logistic regression and descriptive analyses were used.

Diagnosis of oral leukoplakia, oral erythroplakia, oral submucous fibrosis, or oral lichen planus.

Incidence of oral cancer, malignant transformation rate, median time to progression, and associations between demographics and risk factors and the development of oral cancer.

Among 4 225 251 individuals in the database, 4371 were diagnosed with oral cancer (median [IQR] age, 63 [53-71] years; 2610 [59.9%] male; 0.1% of the cohort), and 110 (2.5%) had a preceding OPMD. Oral leukoplakia was found in 1124 patients, with 94 (8.4%) undergoing malignant transformation (median [IQR] time to progression, 25 [7-129] months). HIV-positive patients with oral leukoplakia were more likely to develop oral cancer (odds ratio, 3.80; 95% CI, 1.35-10.70). Of 22 patients with oral erythroplakia, 11 (50.0%) developed oral cancer (median [IQR] time to progression, 3.7 [0.2-334] months). Those who smoked tobacco with oral erythroplakia showed a higher malignant transformation rate (odds ratio, 3.75; 95% CI, 0.54-26.05). Of the 78 patients with oral submucous fibrosis, 4 (5.1%) underwent malignant transformation (median [IQR] time to progression, 36 [36-48] months). Only 1 patient with oral lichen planus developed oral cancer after 5 years.

This cohort study showed that OPMDs have notable but varying propensities to progress to oral cancer. Early detection and monitoring of OPMDs are crucial for improving patient outcomes. However, the risk, etiopathogenesis, and clinical presentation vary for each OPMD and should, therefore, be considered distinct diseases.

The dearth of approved products to treat oral lichen planus (OLP) compels off-label use of dermatological corticosteroid formulations not optimized for indications in the oral cavity. The aims of this study were to develop aqueous micelle based formulations of triamcinolone acetonide (TA) and fluocinonide (FLU), using D-tocopheryl polyethylene glycol succinate, and to investigate corticosteroid delivery to the epithelium-lamina propria junction region - the anatomical target for OLP treatment - in comparison to that from marketed products. Total mucosal deposition of TA after application of Kenacort® A Orabase® (0.1 % TA) and micellar hydrogel (0.1 %) was 242.1 ± 68.5 and 5936.7 ± 1269.6 ng/cm2, respectively. For FLU, deposition after application of Novoter (0.05 % FLU) and micellar hydrogel (0.05 %) was 617.1 ± 126.5 and 2580.0 ± 285.5 ng/cm2, respectively. A buccal biodistribution study showed that application of micelle hydrogels under occlusion for 30 min delivered 117.0 ± 15.6 ng/cm2 and 225.6 ± 36.7 ng/cm2, of TA and FLU, respectively, to the epithelium-lamina propria junction region. In contrast, the amounts deposited after applying Kenacort® A Orabase® and Novoter, were < LOQ. The results demonstrated that TPGS-based micelles improved mucosal bioavailability of TA and FLU in the epithelium-lamina propria junction region and might serve to improve topical OLP therapy.

Clinicopathological diagnosis and follow-up of oral lichen planus and leukoplakia are necessary due to its potential for malignant transformation and the need to differentiate it from other lichenoid diseases and proliferative verrucous leukoplakia. This study aimed to classify and compare sociodemographic and clinicopathological features among patients with oral lichen planus, oral lichenoid lesions and proliferative verrucous leukoplakia.

A transversal observational study in which oral leukoplakia and oral lichen planus patients were surveyed at the Oral Pathological Anatomy Service and Applied Biotechnology Laboratory was conducted. Sociodemographic and clinicopathological data were compared for the lesions studied with the chi-square test or Fisher's exact test.

After classification, 21 oral lichen planus lesions, 34 oral lichenoid lesions and 12 proliferative verrucous leukoplakia lesions were evaluated. Reticular patterns are more characteristic of oral lichen planus and plaque lesions of proliferative verrucous leukoplakia. The buccal mucosa was the most affected site in oral lichen planus lesions, and it was bilateral in all patients. Epithelial dysplasia was present in almost all patients with proliferative verrucous leukoplakia.

Compared with oral lichen planus and proliferative verrucous leukoplakia, oral lichenoid lesions presented intermediate features. This may delay proliferative verrucous leukoplakia diagnosis.

Objectives: Our study aimed to establish the basic reliability parameters of direct immunofluorescence test results in patients with oral lichen planus. Methods: We conducted an evaluation of individual antibody classes in the DIF and ELISA (BP180 antigen), comparing these results with the classical histopathological (HP) examination in a group of patients treated within the standard healthcare in our clinic. Results: Among 66 participants with oral changes indicative of LP, only 50% received histopathological confirmation of the LP diagnosis. Among those with a DIF profile entirely typical for LP (C3+, F+), 57.1% had a positive HP result. Fibrinogen deposits were identified in 42.4% and 36.4% of individuals with positive HP results for F1 and F2, respectively; 78.8% of patients with negative HP and 57.6% with positive HP exhibited no fibrinogen deposits. Simultaneous positivity for F1 and F2 occurred in all cases where F1 was positive. HP confirmed positive DIF for C3 in 50% of cases. Fibrinogen deposits demonstrated the highest diagnostic accuracy (61%). Sensitivity and specificity for fibrinogen deposits were 36% and 42% for F1 and 79% and 82% for F2. The positive predictive values were 67% for F1 and 67% for F2, while the negative predictive values were 58% for F1 and 56% for F2. Overall diagnostic accuracy was reported at 61% for F1 and 59% for F2. Conclusions: Our data indicate the complementarity of HP and immunological test results and the necessity of using both methods together in cases of doubt.

Oral lichen planus (OLP) is a common chronic inflammatory disease with the potential of malignant transformation. Hydroxychloroquine (HCQ), derived from quinine originating from Cinchona spp. bark, is a commonly prescribed off-label for OLP. However, it lacks robust evidence-based medicine practice, as well as theoretical guidance for its pharmacodynamic targets and for mitigating adverse reactions.

To compare the efficacy of HCQ with first-line treatment prednisone for treating severe erosive OLP and to identify compatible phytomedicine that is reasonably available based on elucidating the molecular targets related to clinical benefits and adverse reactions.

We performed a single-center, randomized, investigator-blinded, positive-controlled, non-inferiority trial. Patients who met the enrollment criteria were randomly allocated (1:1) to receive either HCQ or prednisone therapy for 4 weeks and follow-up for 3 months. The primary outcome measures included reductions in the erosion area and pain level. Potential targets of HCQ and associated toxic effects in treating OLP were identified through in silico analysis and validated through histological evaluation. Common hepatoprotective agents, including glycyrrhizin and total glucosides of peony, were analyzed for their potential targets. Then tri-molecular docking study was performed to screen available phytomedicine agent for alleviating adverse reaction of HCQ. Finally, in vitro experiments were performed to validate these targeted effects.

A total of 62 patients were enrolled from January 2021 to August 2023. After a 4-week treatment, there's no significant difference between patients receiving HCQ and PDN in the reduction of erosion area (median, 44 vs 58.5; HCQ - PDN difference: -11; 95 % CI, -39 to 13; p = 0.438) or pain level (median, 3 vs 3; HCQ - PDN difference: 0; 95 % CI, -1 to 1; p = 0.925). Heat shock protein 90 (HSP90) alpha and beta were identified as potential therapeutic targets of HCQ for treating OLP, while HSP90α is also associated with the adverse reactions of HCQ. The expressions of HSP90α and HSP90β in OLP tissue were significantly reduced compared to normal tissue. The phytomedicine glycyrrhizin was selected due to its specific interaction with the GLY-181 site of HSP90α, same as HCQ's toxic targets. HCQ exerted pro-proliferative and anti-inflammatory effects in vitro. And both HCQ and glycyrrhizin treatment restore the expression of HSP90β, while HCQ treatment also restored the expression of HSP90α.

HCQ was not inferior to prednisone for treating severe erosive OLP, suggesting it as an alternative to first-line treatment. Integrating phytopreparation glycyrrhizin into conventional HCQ treatment in OLP can help detoxify by occupying the HSP90α binding site.

Oral lichen planus (OLP) is a chronic inflammatory disorder featured with T lymphocytes infiltration and epithelial basement membrane breakdown. Although matrix metalloproteinase-12 (MMP12) is reported to be involved in the pathogenesis of oral diseases such as oral squamous cell carcinoma and periodontitis, the roles of MMP12 in the context of OLP remain poorly understood. Here, we demonstrate that MMP12 in macrophages derived from mucosal diseased tissues compromises the epithelial barrier integrity in OLP. The increased MMP12 facilitates fibronectin degradation in keratinocytes, leading to oral epithelial barrier disruption. Overexpression of fibronectin in oral keratinocytes prevents epithelial barrier from MMP12-induced damage. In addition, pharmacological inhibition of MMP12 reverses keratinocyte barrier disruption in a cell model. Altogether, our study reveals that MMP12 mediates oral epithelial barrier integrity in the setting of OLP.

In dermatology, lichenoid describes lesions with a violaceous hue that is a clinical reflection of basal cell damage in the epithelium and dense mononuclear infiltrate in the sub-epithelium. The violaceous color results from pigment incontinence due to basal cell damage and the Tyndall effect. Although classically described in lichen planus, a lichenoid hue is noted in the oral mucosa in several other disorders that often lead to diagnostic dilemmas. Early and accurate diagnosis is important for the appropriate management of the underlying condition and prognostication. Dermatologists play a central role in managing such patients since, apart from the oral mucosa findings, the cutaneous features also help to significantly differentiate various conditions. Mimickers of oral lichen planus include nicotine stomatitis, oral submucous fibrosis, oral lichenoid lesions, mucosal discoid lupus erythematosus, pemphigus vulgaris, paraneoplastic pemphigus, mucous membrane pemphigoid, fixed drug eruption, plasma cell cheilitis/gingivitis, and erythema multiforme. While a detailed history and clinical examination can help reach a diagnosis in most cases, histopathology, immunofluorescence, and other relevant investigations help establish the diagnosis.

Cadonilimab is the first approved dual immune checkpoint inhibitor targeting programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), currently utilized for the treatment of various solid tumors. Oral mucosal adverse reactions, such as oral lichenoid lesions, represent one of the most prevalent immune-related adverse events associated with immune checkpoint antibodies. However, reports detailing oral side effects specifically linked to Cadonilimab are lacking. Documenting these side effects is essential to alert oncologists and stomatologists, facilitating timely intervention for affected patients.

We present a case involving a 35-year-old male patient diagnosed with hepatocellular carcinoma who received Cadonilimab following hepatectomy and subsequently developed extensive oral lichenoid lesions along with mucosal erosion at 13-14 weeks post-treatment initiation. A biopsy was conducted revealing immunohistochemical findings of CD3+, CD4+, CD8+, CD20 + lymphocytes, CD68 + macrophages, and α-SMA + myofibroblasts infiltrating the tissue of the oral lichenoid lesions. The patient's oral lesions improved after administration of systemic and local glucocorticoid therapy alongside cessation of Cadonilimab treatment.

This report marks the first documented instance of an oral adverse effect associated with Cadonilimab use. It underscores that administration of this agent may lead to significant lichenoid lesions and erosions within the oral cavity-an issue warranting increased vigilance from both oncologists and stomatologists.

Oral lichen planus (OLP) and oral lichenoid mucositis (OLM) are immune-mediated mucosal conditions with multifactorial etiology, with similar clinical and histological characteristics. Diagnosis should be confirmed considering both clinical and histological aspects. Some subsets are associated with immune-mediated thyroid dysfunction due to anti-thyroid peroxidase antibody (TPO) and anti-thyroglobulin antibody (TGA).

To ascertain the presence of thyroid autoantibodies in a cohort of patients with OLP and OLM from a South Indian population.

This observational study comprised 21 patients with 7 cases of OLP (Group I) and 14 cases of OLM (Group II) who reported from 2021-2023 for 2 years. Serum anti-thyroid antibodies including TPO and TGA was estimated using chemiluminescence immunoassay technique along with clinical and histological aspects. Altered levels of serological parameters were compared with respect to these auto-immune conditions.

Increased level of thyroid autoantibodies was observed in three (42%) of the seven cases of OLP. Two cases had elevated TPO (3-4 folds) and TGA (6-38 folds) and the subjects were above 50 years. Seven (50%) of the 14 OLM cases exhibited increased thyroid autoantibody levels and were above 50 years, predominantly females. TPO levels were increased in the range of 12 to 178 and TGA from 2 to 136 folds. Duration of these lesions were more than a year.

Increased thyroid autoantibodies observed in both OLP and OLM represent an underlying autoimmune response. Long-term monitoring will enable the clinicians to correlate the antibody levels with the management of these lesions.

To evaluate whether hydroxychloroquine (HCQ) or chloroquine (CQ) are effective for the treatment of oral lichen planus (OLP).

A literature search was conducted in four databases. Clinical studies investigating the effect of HCQ/CQ in patients with OLP were included.

Eleven studies were included. Four were RCTs and seven quasi-experimental studies. The studies included 390 patients diagnosed with OLP, of which 326 and 7 received HCQ and CQ, respectively. 46 patients received topical dexamethasone, 5 placebo and 6 griseofulvin as controls. Five studies assessed pain, and all of them obtained pain reduction with the use of HCQ. Six studies reported objective clinical improvement of OLP with the use of HCQ. Five studies that used a subjective scale obtained that 24%-100% of the patients achieved a complete/almost complete improvement of OLP lesions and its symptomatology. The most frequent side effects were vision problems, gastric discomfort, rash, nauseas, headaches, skin pigmentation, and elevated kidney function. 17 patients had to withdraw from the studies.

Current evidence is scarce to confirm HCQ as a therapeutic option for OLP. More RCTs are needed to compare its efficacy with topical corticosteroids and to evaluate whether HCQ reduces relapses of OLP.

There is an urgent need to update the evidence available on the efficacy of photobiomodulation (PBM) in comparison to topical corticosteroids in the management of Oral Lichen Planus (OLP).

Cochrane Oral Health's Trials Register, Cochrane Central Register of Controlled Trials in the Cochrane Library, MEDLINE Pubmed, SCOPUS, Lilacs and Google Scholar were searched. Other sources included US National Institutes of Health Ongoing Trials Register, World Health Organization International Clinical Trials Registry Platform and Clinical Trial Registry - India were searched using variations of the keywords "Laser" and "Oral Lichen Planus". Randomized controlled trials comparing PBM and topical corticosteroids in the resolution of pain among OLP patients were included. The studies were assessed using the Cochrane Risk-of-Bias assessment tool. Publication bias was assessed using a funnel plot, and the certainty of evidence was evaluated according to the GRADE guidelines.

Ten studies were included for qualitative assessment and of these eight were included in the meta-analysis. The included studies used laser parameters of varying strengths and duration. Meta-analysis favoured PBM (n = 274, MD =-0.48, CI -0.66- -0.30) for pain score. No adverse effects were reported for laser therapy. There was high heterogeneity and moderate certainty of evidence, and most studies had a high risk of bias.

There is improvement in the clinical parameters of OLP when treated with PBM in comparison to topical corticosteroids. However, the strength of the evidence for these findings in limited. It is recommended to conduct better long-term trials with large sample size.

Background/Objectives: Oral Lichen Planus (OLP) is a common immune-mediated inflammatory disorder affecting the oral mucosa, impacting 0.5% to 2% of the global population, primarily middle-aged women. Immunological dysregulation is a key factor in OLP's pathogenesis, involving CD4+ T helper and CD8+ T cytotoxic cells. The World Health Organization (WHO) classifies OLP as a potentially malignant disorder, with a risk of oral squamous cell carcinoma (OSCC) developing in up to 2% of lesions. This narrative review aims to provide a comprehensive overview of the etiopathogenesis, clinical manifestations, diagnostic criteria, and therapeutic strategies for OLP, informing clinical practice and guiding future research. Methods: A review of the literature from the PubMed and Google Scholar databases was conducted up to December 2023, focusing on studies addressing the etiopathogenesis, diagnosis, clinical manifestations, and treatment of OLP. Results: OLP's pathogenesis is driven by immune dysregulation, with CD4+ and CD8+ cells playing crucial roles. Clinically, OLP presents as reticular, erosive, bullous, and plaque-like lesions. Diagnosis relies on clinical examination, histopathology, and direct immunofluorescence. Recent advancements in diagnostic markers and imaging techniques have improved detection and monitoring. Treatment primarily involves corticosteroids, but novel therapies such as curcumin, retinoids, and laser therapy are increasingly used for their effectiveness and reduced side effects. These treatments show promise in symptom reduction and recurrence prevention, although long-term data are needed. Conclusions: Regular screenings and biopsies are essential due to OLP's likelihood of malignant transformation. This study urges further investigation into long-term results, improved diagnostic techniques, and evidence-based treatment regimens.

Lichen planus is one of the common adverse reactions after COVID-19 infection and vaccination. Despite it being reported in several case reports, the literature including a large sample of the studied population is lacking. The current study was performed to assess the risk of LP after COVID-19 infection as well as COVID-19 vaccination.

The current study was designed as a retrospective cross-sectional hospital-based study of registered patients at the University of Florida (UF) health centers. The diagnoses of LP, COVID-19 infection, and COVID-19 vaccines were detected. The logistic regression model was used to assess the risk of developing LP after COVID-19 infection and vaccination.

A total hospital patient of 684,110 attended UF Health centers were included in this study. 181 patients reported LP after COVID-19 vaccination and 24 patients developed LP after COVID-19 infection. The risk of developing LP after COVID-19 vaccination was 1.573 while the risk of developing LP after COVID-19 infection was 1.143.

The odds of getting LP after COVID-19 vaccination are significantly developed. The current study showed that COVID-19 infection and vaccination are associated with LP. So, healthcare practitioners should be aware of this reaction for rapid recognition and treatment.

Oral lichen planus (OLP) and oral lichenoid lesion (OLL) are chronic inflammatory diseases involving the oral mucosa. B cells infiltration in OLP and OLL, however, little is known about these cells in OLP and OLL. To analyze the function and infiltrating features of B lymphocytes in OLP and OLL, and to preliminarily evaluate their correlation with clinical outcomes. Tissue samples were collected from OLP, OLL, and healthy mucosa. The phenotypes and amounts of B cells in tissues were analyzed by single-cell sequencing. Their proportion and infiltrating features in tissues were examined by immunohistochemistry and immunofluorescence. With the systemic medication of corticoids, the correlation between B cells infiltrating characteristics and the clinical outcomes were evaluated. A quantified proportion increase of B cells was shown in both OLP and OLL. B cells in OLP demonstrated heightened activation and enhanced regulation in immune response. A cohort of 100 patients with OLP/OLL and 13 healthy controls were examined to investigate the B cells infiltration pattern. B cells were distributed in the superficial layer of lamina propria in 92.9% and 41.9% of OLP and OLL, respectively(P < 0.01); focally distributed in 25.0% and 62.9% of OLP and OLL, respectively(P < 0.01). With the systemic medication of corticoids, the cases with B cell infiltration (B+) in OLP and OLL groups showed a statistically significant reduction in REU scores before and after treatment (P < 0.01). B cells are widely present in OLP and OLL, and B cell infiltration in OLP and OLL are related to the better therapeutic effect of oral corticoids.

The diagnosis of oral lichen planus (OLP) poses many challenges due to its nonspecific clinical symptoms and histopathological features. Therefore, the diagnostic process should include a thorough clinical history, immunological tests, and histopathology. Our study aimed to enhance the diagnostic accuracy of OLP by integrating direct immunofluorescence (DIF) results with clinical data to develop a multivariate predictive model based on the Artificial Neural Network. Eighty patients were assessed using DIF for various markers (immunoglobulins of classes G, A, and M; complement 3; fibrinogen type 1 and 2) and clinical characteristics such as age, gender, and lesion location. Statistical analysis was performed using machine learning techniques in Statistica 13. The following variables were assessed: gender, age on the day of lesion onset, results of direct immunofluorescence, location of white patches, locations of erosions, treatment history, medications and dietary supplement intake, dental status, smoking status, flossing, and using mouthwash. Four statistically significant variables were selected for machine learning after the initial assessment. The final predictive model, based on neural networks, achieved 85% in the testing sample and 71% accuracy in the validation sample. Significant predictors included stress at onset, white patches under the tongue, and erosions on the mandibular gingiva. In conclusion, while the model shows promise, larger datasets and more comprehensive variables are needed to improve diagnostic accuracy for OLP, highlighting the need for further research and collaborative data collection efforts.

Oral lichen planus (OLP) is a common oral mucosal disease, clinically categorized into erosive OLP (EOLP) and non-erosive OLP (NEOLP) based on symptoms, but its pathogenic mechanism remains unclear. This study aims to explore the relationship between OLP and the oral microbiome.

We collected oral mucosal samples from 49 patients and 10 healthy individuals and conducted 16S rRNA and ITS gene sequencing to explore the oral fungal and bacterial communities.

We observed significantly lower α diversity of fungi in the EOLP group, with Candida being significantly enriched as the main dominant genus. In the NEOLP group, Aspergillaceae were significantly enriched. The EOLP group showed significant enrichment of Aggregatibacter and Lactobacillus, but the relative abundance of Streptococcus was notably lower than in the other two groups. In the NEOLP group, two species including Prevotella intermedia were significantly enriched. The microbial co-occurrence and co-exclusion networks display distinct characteristics across the three groups, with Lactobacillus assuming a significant bridging role in the ELOP group.

Our study indicates that EOLP and NEOLP experience varying degrees of dysbiosis at both the fungal and bacterial levels. Therefore, the pathogenic mechanisms and interactive relationships of these microbiota associated with OLP merit further in-depth investigation.

The familial type of oral lichen planus (OLP) is rare, with a paucity of data regarding its clinical significance. Our objective was to characterize patients with familial OLP.

Families with at least two members diagnosed with OLP were included. Clinical and demographic data and medical history were recorded.

Twenty families, 19 Jewish and 1 Arab, were identified. Of the Jewish families, 57.8% were non-Ashkenazi, originating mainly from central Asia. Of those with OLP there were 14 males and 23 females with an average age of 49.1. Dyslipidemia, cardiovascular, and thyroid disorders (27.7%, 22.2%, and 16.6%, respectively) were the most common comorbidities. Five patients from five distinct families had oral cancer, two with second primary.

To the best of our knowledge, this is the largest study describing familial OLP. The predominant and common ethnicity of the families with multiple members diagnosed with OLP may imply an ethnic tendency. The higher tendency of hypothyroidism and the high percentage of OSCC among familial OLP patients might be connected to familial OLP and the latter suggests that this population is predisposed to malignant transformation. Thus, this group should be considered as a high-risk group.

Innate lymphoid cells (ILCs), as newly discovered antigen-independent innate immune cells, respond promptly to stimuli by secreting effector cytokines to exert effector functions similar to those of T cells. ILCs predominantly reside at mucosal sites and play critical roles in defending against infections, maintaining mucosal homeostasis, regulating inflammatory and immune responses, and participating in tumorigenesis. Recently, there has been a growing interest in the role of ILCs in oral diseases. This review outlines the classifications and the major characteristics of ILCs, and then comprehensively expatiates the research on ILCs in oral cancer, primary Sjogren's syndrome, periodontal diseases, oral lichen planus, oral candidiasis, Behcet's disease, and pemphigus vulgaris, aiming at summarising the implications of ILCs in oral diseases and providing new ideas for further research.

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.

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.

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).

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.

To determine the factors that affected the complete clinical remission of oral lichen planus (OLP) treated with topical corticosteroids.

We retrospectively evaluated the charts of patients diagnosed as OLP. Age, sex, current medical conditions, medications, type of OLP, Thongprasom score, pain level assessed by a numeric rating scale (NRS), Candida infection, topical steroid treatment preparation, duration of treatment until the first complete clinical remission, and follow-up duration were assessed as variables.

In total 100 patients, after complete remission, 22 patients reported a relapse within 1.5-45 months, with a mean of 15.6 ± 13.2 months. Age, duration, gingiva and vestibule area, hypertension, dyslipidemia, Thongprasom score, preparation and topical corticosteroid potency were factors affecting the remission. Multivariate logistic regression analysis revealed that the patients' age and duration of treatment were significant factors after adjusted for age, sex, and independent factors with a P-value < 0.1 in the univariate analysis. The likelihood of having incomplete remission of the OLP lesion increased by 7.9% for every year increase in age and increased by 2.3% for every month of treatment.

There are many different factors between the complete remission and incomplete remission groups. However, age and duration of treatment were significant factors affecting the remission of OLP.

Individuals diagnosed with a chronic oral disease that increase the risk of mouth cancer, such as oral epithelial dysplasia (OED), require appropriate knowledge to make informed decisions. The present study aimed to assess whether patient information needs of a group of patients concerning dysplasia were met and to what degree clinicians agree with patients on 'important' topics.

This represented secondary analyses of a cross-sectional study to assess the information needs of 86 patients diagnosed with dysplasia compared with those of 77 clinicians using the validated OED Information Needs Questionnaire. Descriptive, concordance and regression analyses were performed for the collected data.

The mean and median total scores for all items in the amount of information received subscale were 2.33 and 2.44, indicating overall unmet needs concerning dysplasia. Clinicians were generally able to predict topics of greatest importance to patients, although their scores were mainly lower than those of patients (k = 0.06). There was a higher agreement between patients (k = 0.25) than clinicians (k = 0.09).

Clinicians are encouraged to assess a patient's information needs to ensure tailored and patient-centred communication concerning OED during all clinical consultations.

Glucocorticoids suppress the hypothalamic-pituitary-adrenal axis, which may lead to glucocorticoid-induced adrenal insufficiency. The study aimed to investigate the prevalence of this state in patients with oral lichen planus treated with topical clobetasol propionate.

In this cross-sectional study, 30 patients with oral lichen planus receiving long-term (>6 weeks) clobetasol propionate gel 0.025% were invited to participate. Adrenal function was assessed by measuring morning plasma cortisol after a 48-h withdrawal of clobetasol treatment. In patients with plasma cortisol <280 nmol/L, a cosyntropin stimulation test was performed.

Twenty-seven patients were included. Twenty-one (78%) patients presented with plasma cortisol ≥280 nmol/L (range 280-570 nmol/L), and six (22%) <280 nmol/L (range 13-260 nmol/L). Five of these six patients underwent cosyntropin stimulation that revealed severe adrenal insufficiency in two patients (cortisol peak 150 nmol/L and 210 nmol/L) and mild adrenal insufficiency in three patients (cortisol peak 350-388 nmol/L).

In this study, approximately 20% of patients receiving intermittent topical glucocorticoid treatment for oral lichen planus had glucocorticoid-induced adrenal insufficiency. It is essential for clinicians to be aware of this risk and to inform patients about the potential need for glucocorticoid stress doses during intercurrent illness.

The objective of this study is to describe the efficacy of hydroxychloroquine (HCQ) in patients with oral lichen planus (OLP) refractory to conventional therapy.

In this single-center retrospective study, patients were prescribed HCQ 200 mg twice daily. Pain, reticulation, erythema, and ulceration scores were recorded. Two-sample and paired t tests were used to evaluate mean and paired pain scores and paired t test to determine substantial differences in paired REU scores, at HCQ initiation visit and final follow-up at 12 to 24 months.

Thirty-six patients (69.4% female) with a median age of 70 ± 12.0 (range 48-99) were initiated on HCQ. Only 30 patients were evaluable because pruritus developed in 5 patients (13.9%) and gastrointestinal symptoms in 1 (2.8%). The mean follow-up was 23.2 months (range 1-74). In 19 patients, there was a significant decline in the worst pain score from a mean of 3.9 (SD± 2.8, n = 19) to 1.9 (SD ± 2.4, n = 19) (t = 2.837, P < .006). Paired reticulation, erythema, and ulceration (REU scores) decreased from a weighted mean score of 16.0 (SD ± 8.0, n = 12) to 12.0 (SD ± 6.3, n = 12) (t = 2.07, P < .032).

Hydroxychloroquine was a suitable option and effective in reducing symptoms and disease severity in patients with recalcitrant OLP who do not adequately respond to standard therapy.

Erosive oral lichen planus (EOLP) represents a significant challenge in dental and medical management due to its chronic inflammatory nature, painful symptoms, and impact on quality of life. This study aims to evaluate the current diagnostic approach with novel non-invasive techniques, such as dermoscopy, and also the landscape of treatment options for EOLP, focusing on its efficacy, safety, and the challenges that it present in clinical practice. Through a comprehensive literature review, we explored the use of topical corticosteroids, systemic immunosuppressants, biologics, and Janus kinase (JAK) inhibitors in treating EOLP, alongside examining patient compliance, psychological impacts, and the risk of adverse effects and recurrence. Our findings reveal that while topical corticosteroids are the cornerstone of EOLP treatment, offering symptomatic relief, their long-term use is limited by side effects and tolerance development. Systemic therapies and biologics provide alternatives for refractory cases but necessitate careful adverse effect monitoring. JAK inhibitors show promise as an innovative treatment avenue but require more evidence on long-term safety and efficacy. This study highlights the necessity of personalized treatment approaches due to the variable disease course and response to treatment, underscoring the importance of a multidisciplinary strategy in managing EOLP. The complexity of EOLP treatment, compounded by its psychological and quality of life impacts, demands ongoing research into targeted therapies, the establishment of standardized treatment protocols, and the development of effective outcome measures to improve patient care and treatment outcomes.

Previous randomized controlled trials (RCTs) suggested that gut microbiota-based therapies may be effective in treating autoimmune diseases, but a systematic summary is lacking.

Pubmed, EMbase, Sinomed, and other databases were searched for RCTs related to the treatment of autoimmune diseases with probiotics from inception to June 2022. RevMan 5.4 software was used for meta-analysis after 2 investigators independently screened literature, extracted data, and assessed the risk of bias of included studies.

A total of 80 RCTs and 14 types of autoimmune disease [celiac sprue, SLE, and lupus nephritis (LN), RA, juvenile idiopathic arthritis (JIA), spondyloarthritis, psoriasis, fibromyalgia syndrome, MS, systemic sclerosis, type 1 diabetes mellitus (T1DM), oral lichen planus (OLP), Crohn's disease, ulcerative colitis] were included. The results showed that gut microbiota-based therapies may improve the symptoms and/or inflammatory factor of celiac sprue, SLE and LN, JIA, psoriasis, PSS, MS, systemic sclerosis, Crohn's disease, and ulcerative colitis. However, gut microbiota-based therapies may not improve the symptoms and/or inflammatory factor of spondyloarthritis and RA. Gut microbiota-based therapies may relieve the pain of fibromyalgia syndrome, but the effect on fibromyalgia impact questionnaire score is not significant. Gut microbiota-based therapies may improve HbA1c in T1DM, but its effect on total insulin requirement does not seem to be significant. These RCTs showed that probiotics did not increase the incidence of adverse events.

Gut microbiota-based therapies may improve several autoimmune diseases (celiac sprue, SLE and LN, JIA, psoriasis, fibromyalgia syndrome, PSS, MS, T1DM, Crohn's disease, and ulcerative colitis).

Oral lichen planus, a chronic inflammatory immune disease, occurs in the oral mucosa. We aimed to assess the prevalence and possible influencing factors of oral lichen planus in patients with diabetes mellitus.

This cross-sectional study involved 525 patients with diabetes mellitus and 525 controls. We collected information on blood glucose level, duration of diabetes, diabetic complications, treatment methods, other systemic diseases and medication history.

Oral lichen planus was significantly more prevalent in the diabetes mellitus/type 2 diabetes mellitus group than in the controls (2.3%/2.2% vs. 0.6%, p = 0.019/0.022). There was no significant association between patients with diabetes mellitus with and those without oral lichen planus in age (p = 0.195), sex (p = 0.390), blood glucose level (p = 1), duration of diabetes (p = 0.638), diabetic complications (p = 1), treatment methods (p = 0.962), other systemic diseases (p = 0.891) and medication history (p = 0.848).

Diabetes mellitus was associated with oral lichen planus; there was a higher prevalence of oral lichen planus in patients with diabetes mellitus/type 2 diabetes mellitus than in those without diabetes. Oral lichen planus development in patients with diabetes mellitus was not significantly associated with age, sex, blood glucose level, duration of diabetes, diabetic complications, treatment methods, other systemic diseases and medication history.

To investigate the role of oral lichen planus (OLP) on the long-term prognosis of oral epithelial dysplasia (OED).

Retrospective single-centre cohort study using the 2007-2019 database of the Head and Neck Cancer and Oral Medicine units of University College London Hospital. The exposure of interest was the presence of OLP, and the prognostic outcomes included the development of new primary episodes of OED, progression to malignancy and mortality. Cox proportional hazard and Poisson regression models were performed.

A total of 299 patients, of whom 144 had OED arising on the background of OLP (OLP/OED) and 155 had OED without underlying OLP (non-OLP/OED), were included. A pre-existing diagnosis of OLP was significantly associated with a twofold increased risk of subsequent primary OED events (HR = 2.02, p = 0.04), which also developed faster (1.46 vs. 2.96 years, p = 0.04) and with more involvement of non-cancer-prone sites (p = 0.001) than in the non-OLP/OED group. There was no difference between groups in the progression to malignancy or mortality.

Oral lichen planus/OED patients are at higher risk of multiple episodes of primary OED, which can develop faster and at non-cancer-prone sites as compared to non-OLP/OED individuals. Further research is needed to clarify the effects of OLP upon progression to OSCC and mortality.

Background: Oral potentially malignant disorders (OPMDs) are a group of chronic oral mucosal diseases associated with an increased risk of malignant transformation. Multiple studies have investigated the prevalence of these conditions in multiple regions; however, there are limited data about the prevalence of OPMDs in the Kingdom of Saudi Arabia (KSA). This paper aims to review the prevalence of OPMDs in the KSA, to ensure better understanding of the population risk and propose a more standardised approach to the diagnosis and management of this group across the KSA. In addition, this review will discuss the prevalence of oral cancer in the KSA, considering independent risk factors for oral cancer development. Methods: Electronic databases including PubMed, Medline, Medscape, ScienceDirect, StatPearls, BMC Oral Health and the Cochrane Library were searched with the keywords "Oral Potentially Malignant Disorders"; "Saudi Arabia"; and "Oral Cancer". Identified articles were reviewed independently by 2 reviewers against defined inclusion and exclusion criteria. Results: 16 studies were included in this review. The prevalence of OPMDs in KSA varies significantly depending on age, gender, social habits, background disease and dental status. Conclusions: This review highlights the need for up-to-date data on the prevalence, distribution, and characteristics of OPMDs in KSA. The diverse prevalence rates and distinct characteristics of various OPMDs emphasise the necessity for targeted preventive measures. As the data on OPMDs in KSA remains limited, future research efforts should prioritise the establishment of comprehensive epidemiological studies to inform effective public health interventions in this region.