ABSTRACT
Stromal cells are key components of the tumour microenvironment (TME) and their incorporation into 3D engineered tumour-stroma models is essential for tumour mimicry. By engineering tumouroids with distinct tumour and stromal compartments, it has been possible to identify how gene expression of tumour cells is altered and influenced by the presence of different stromal cells. Ameloblastoma is a benign epithelial tumour of the jawbone. In engineered, multi-compartment tumouroids spatial transcriptomics revealed an upregulation of oncogenes in the ameloblastoma transcriptome where osteoblasts were present in the stromal compartment (bone stroma). Where a gingival fibroblast stroma was engineered, the ameloblastoma tumour transcriptome revealed increased matrix remodelling genes. This study provides evidence to show the stromal-specific effect on tumour behaviour and illustrates the importance of engineering biologically relevant stroma for engineered tumour models. Our novel results show that an engineered fibroblast stroma causes the upregulation of matrix remodelling genes in ameloblastoma which directly correlates to measured invasion in the model. In contrast the presence of a bone stroma increases the expression of oncogenes by ameloblastoma cells.
ABSTRACT
OBJECTIVES: To investigate the role of oral lichen planus (OLP) on the long-term prognosis of oral epithelial dysplasia (OED). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Subject(s)
Carcinoma, Squamous Cell , Lichen Planus, Oral , Mouth Neoplasms , Humans , Lichen Planus, Oral/pathology , Mouth Neoplasms/pathology , Retrospective Studies , Cohort Studies , Carcinoma, Squamous Cell/pathology , Hyperplasia , PrognosisABSTRACT
PURPOSE: Radiation therapy-induced xerostomia significantly affects quality of life in head and neck cancer survivors. Neuro-electrostimulation of the salivary glands may safely increase natural salivation and reduce dry mouth symptoms. METHODS AND MATERIALS: This multicenter, double-masked, randomized, sham-controlled clinical trial assessed the long-term effects of a commercially available intraoral neuro-electrostimulating device in lessening xerostomia symptoms, increasing salivary flow, and improving quality of life in individuals with radiation therapy-induced xerostomia. Using a computer-generated randomization list, participants were assigned (1:1) to an active intraoral custom-made removable electrostimulating device or a sham device to be used for 12 months. The primary outcome was the proportion of patients reporting a 30% improvement on the xerostomia visual analog scale at 12 months. A number of secondary and exploratory outcomes were also assessed through validated measurements (sialometry and visual analog scale) and quality-of-life questionnaires (EORTC QLQ-H&N35, OH-QoL16, and SF-36). RESULTS: As per protocol, 86 participants were recruited. Intention-to-treat analyses showed no statistical evidence of a difference between the study groups with respect to the primary outcome or for any of the secondary clinical or quality-of-life outcomes. Exploratory analyses showed a statistically significant difference in the changes over time of the dry mouth subscale score of the EORTC QLQ-H&N35 in favor of the active intervention. CONCLUSIONS: LEONIDAS-2 did not meet the primary and secondary outcomes.
Subject(s)
Electric Stimulation Therapy , Head and Neck Neoplasms , Radiation Injuries , Xerostomia , Humans , Quality of Life , Xerostomia/etiology , Xerostomia/therapy , Salivation , Salivary Glands , Head and Neck Neoplasms/radiotherapy , Radiation Injuries/therapy , Electric Stimulation Therapy/methodsABSTRACT
OBJECTIVES: The aim of this cross-sectional study was to explore the structural validity and internal consistency reliability of General Anxiety Disorder-7, Patient Health Questionnaire-8, 15 and Jaw Functional Limitation Scale-20 in patients with chronic pain of temporomandibular disorders. MATERIALS AND METHODS: Validity and reliability were assessed in 129 patients diagnosed according to the diagnostic criteria for temporomandibular disorders. Structural validity was explored using factor analysis, and internal consistency by calculating Cronbach α. RESULTS: Confirmatory factor analysis revealed a suitable 2-factor model for Patient Health Questionnaire-8, with Cronbach α of 0.89, and 0.86. One and 2-factor models were suitable for General Anxiety Disorder-7, with overall Cronbach α of 0.93 for the 1-factor model, and 0.91 and 0.84 for both factors in a 2-factor model. A 4-factor solution was appropriate for Patient Health Questionnaire-15, with Cronbach α of 0.72, 0.57, 0.71 and 0.73 for each factor separately. Exploratory factor analysis was conducted to explore the factor structure of Jaw Functional Limitation Scale 20, and a 3-factor solution was appropriate. CONCLUSIONS: This study provides positive evidence of structural validity and internal consistency of these questionnaires in patients with pain of temporomandibular disorders. However, additional testing is required to explore further psychometric properties.
ABSTRACT
OBJECTIVES: 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. SUBJECTS AND METHODS: 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. RESULTS: 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). CONCLUSION: Clinicians are encouraged to assess a patient's information needs to ensure tailored and patient-centred communication concerning OED during all clinical consultations.
ABSTRACT
OBJECTIVES: Online information on oral epithelial dysplasia (OED) is insufficient and of low quality. While only written information has been previously assessed, this study aims to evaluate the content and quality of audiovisual (AV) online information about OED. METHODS: One hundred and twenty-seven materials were initially considered using six key words across two search engines (YouTube and Google). Ultimately, 29 materials remained for the final assessment. These materials were then analysed for content, quality (DISCERN instrument, JAMA benchmarks), understandability and actionability. RESULTS: Most contents were scientific (n = 25), while three videos were educational, and one video was a personal experience with OED. On a scale of 1-5, the overall DISCERN score was (mean ± SD = 2.26 ± 0.79), suggesting poor quality of information. Regarding JAMA benchmarks, there was no single material that fulfilled or lacked all four benchmarks. The overall mean understandability score was 82% and the actionability mean score was significantly low at 29%. CONCLUSION: Although the vast majority of AV materials on OED were primarily produced for scientific purposes, these materials could be helpful as resources for patient education. Keeping in mind, however, that the desired quality and essential patient information about OED available online remains largely poor and missing.
ABSTRACT
INTRODUCTION: The importance of the patients' clinical experience has been reinforced several times over the last decade by healthcare organisations and policy makers. Routine gathering of experience data can help in enhancing patient-centred care and provide guidance to quality improvement schemes. Patient-reported experience measures can help to that end. The aim of this study was to develop a patient-reported experience measure to evaluate the experience of patients with temporomandibular disorders while receiving healthcare. METHODS: Input from several sources was utilised to develop the tool; previous literature, patients with temporomandibular disorders, and experts in the field. A qualitative study was conducted following the COnsensus-based Standards for the selection of health Measurement Instruments guidance to generate the items of the questionnaire, which subsequently underwent cognitive testing. RESULTS: Seventeen patients took part in the qualitative study, in addition to six healthcare professionals. The preliminary questionnaire consisted of 28 questions with six response options. CONCLUSIONS: This patient-reported experience measure is a brief tool to evaluate the clinical experience of patients with temporomandibular disorders. Patients' involvement ensured face and content validity of the questionnaire, in addition to the relevance, comprehensibility and comprehensiveness of the items.
Subject(s)
Chronic Pain , Temporomandibular Joint Disorders , Humans , Chronic Pain/diagnosis , Patient Reported Outcome Measures , Surveys and Questionnaires , Qualitative Research , Temporomandibular Joint Disorders/complications , Temporomandibular Joint Disorders/diagnosis , Reproducibility of ResultsABSTRACT
AIMS: To identify the range of patient-reported outcome measures (PROMs) used in TMD studies, summarize the available evidence for their psychometric properties, and provide guidance for the selection of such measures. METHODS: A comprehensive search was conducted to retrieve articles published between 2009 and 2018 containing a patient-reported measure of the effects of TMDs. Three databases were searched: MEDLINE, Embase, and Web of Science. RESULTS: A total of 517 articles containing at least one PROM were included in the review, and 57 additional studies were also located describing the psychometric properties of some tools in a TMD population. A total of 106 PROMs were identified and fell into the following categories: PROMs describing the severity of symptoms; PROMs describing psychologic status; and PROMs describing quality of life and general health. The most commonly used PROM was the visual analog scale. However, a wide range of verbal descriptors was employed. The Oral Health Impact Profile-14 and Beck Depression Inventory were the most commonly used PROMs describing the effect of TMDs on quality of life and psychologic status, respectively. Additionally, the Oral Health Impact Profile (various versions) and the Research Diagnostic Criteria Axis ll questionnaires were the instruments most repeatedly tested in a TMD population, and these instruments have undergone cross-cultural validation in several languages. CONCLUSION: A wide range of PROMs have been used to describe the impact of TMDs on patients. Such variability may limit the ability of researchers and clinicians to evaluate the efficacy of different treatments and make meaningful comparisons.
Subject(s)
Quality of Life , Temporomandibular Joint Disorders , Humans , Temporomandibular Joint Disorders/therapy , Databases, Factual , Language , Patient Reported Outcome MeasuresABSTRACT
BACKGROUND: Effective treatments for dry mouth of Sjogren's syndrome are limited and hampered by adverse effects. The aim of LEONIDAS-1 was to explore the feasibility of salivary electrostimulation in individuals with primary Sjogren's syndrome, as well as parameters required to inform the design of a future phase III trial. METHODS: Multicentre, parallel-group, double-blind, randomised sham-controlled trial in two UK centres. Participants were randomised (1:1, computer-generated) to active or sham electrostimulation. The feasibility outcomes included screening/eligibility ratio, consent, and recruitment and drop-out rates. Preliminary efficacy outcome included dry mouth visual analogue scale, Xerostomia Inventory, the EULAR Sjögren's syndrome patient reported index-Q1, and unstimulated sialometry. RESULTS: Forty-two individuals were screened, of whom 30 (71.4%) met the eligibility criteria. All eligible individuals consented to recruitment. Out of the 30 randomised participants (active n = 15, sham n = 15), 4 dropped out and 26 (13 vs. 13) completed all study visits as per protocol. Recruitment rate was 2.73 participants/month. At 6-month post-randomisation the difference in mean reduction in visual analogue scale, xerostomia inventory and EULAR Sjögren's syndrome patient reported index-Q1 scores between groups were 0.36 (95% CI: -0.84, 1.56), 3.31 (0.43, 6.18), and 0.23 (-1.17, 1.63), respectively; unstimulated salivary flow increased by a mean of 0.98 mL/15 min, all in favour of the active group. No adverse events were reported. CONCLUSION: LEONIDAS-1 results support progression to a phase III definitive randomised controlled trial of salivary electrostimulation in individuals with Sjogren's syndrome. Xerostomia inventory could be considered the primary patient-centred outcome measure and the corresponding observed treatment effect could inform the sample size of a future trial.
Subject(s)
Sjogren's Syndrome , Xerostomia , Humans , Sjogren's Syndrome/complications , Sjogren's Syndrome/therapy , Feasibility Studies , Xerostomia/etiology , Xerostomia/therapy , Treatment Outcome , Double-Blind MethodABSTRACT
Aims: To systematically review the qualitative evidence related to experiences of patients with temporomandibular disorders (TMD) and to explore their journeys within health care services. Methods: A systematic search of the following databases was conducted: MEDLINE, Embase, PsycINFO, Web of Science, CINAHL Complete, and the Cochrane database. Thematic synthesis was used to analyze and synthesize the data from qualitative studies that explored the journeys of TMD patients within health care services. The Critical Appraisal Skills Programme (CASP) tool was used to critically appraise the quality of the included studies. Results: The search strategies yielded 4,563 articles across all databases, and 18 articles were eventually included. Six themes were derived: care-seeking attitudes; expectations and health care experience; the patient-clinician interaction; diagnosis as a stepping stone for improvement; management; and social support. Conclusion: The journey within health care services may play a valuable role in the ability to cope with chronic TMDs. Receiving a diagnosis, being listened to, and being believed are among the most important elements making for a positive clinical experience.
Subject(s)
Delivery of Health Care , Health Services , Qualitative Research , Temporomandibular Joint Disorders , Humans , Social Support , Temporomandibular Joint Disorders/diagnosis , Temporomandibular Joint Disorders/psychology , Temporomandibular Joint Disorders/therapy , Patient Acceptance of Health Care , Chronic Disease , Physician-Patient Relations , Clinical Competence , MotivationABSTRACT
BACKGROUND: Delays in the identification and referral of oral cancer remain frequent. An accurate and non-invasive diagnostic test to be performed in primary care may help identifying oral cancer at an early stage and reduce mortality. Point-of-care Analysis for Non-invasive Diagnosis of Oral cancer (PANDORA) was a proof-of-concept prospective diagnostic accuracy study aimed at advancing the development of a dielectrophoresis-based diagnostic platform for oral squamous cell carcinoma (OSCC) and epithelial dysplasia (OED) using a novel automated DEPtech 3DEP analyser. METHODS: The aim of PANDORA was to identify the set-up of the DEPtech 3DEP analyser associated with the highest diagnostic accuracy in identifying OSCC and OED from non-invasive brush biopsy samples, as compared to the gold standard test (histopathology). Measures of accuracy included sensitivity, specificity, positive and negative predictive value. Brush biopsies were collected from individuals with histologically proven OSCC and OED, histologically proven benign mucosal disease, and healthy mucosa (standard test), and analysed via dielectrophoresis (index test). RESULTS: 40 individuals with OSCC/OED and 79 with benign oral mucosal disease/healthy mucosa were recruited. Sensitivity and specificity of the index test was 86.8% (95% confidence interval [CI], 71.9%-95.6%) and 83.6% (95% CI, 73.0%-91.2%). Analysing OSCC samples separately led to higher diagnostic accuracy, with 92.0% (95% CI, 74.0%-99.0%) sensitivity and 94.5% (95% CI, 86.6%-98.5%) specificity. CONCLUSION: The DEPtech 3DEP analyser has the potential to identify OSCC and OED with notable diagnostic accuracy and warrants further investigation as a potential triage test in the primary care setting for patients who may need to progress along the diagnostic pathway and be offered a surgical biopsy.
Subject(s)
Carcinoma, Squamous Cell , Head and Neck Neoplasms , Mouth Neoplasms , Humans , Mouth Neoplasms/pathology , Carcinoma, Squamous Cell/pathology , Squamous Cell Carcinoma of Head and Neck , Prospective Studies , Point-of-Care Systems , Biomarkers, Tumor/metabolism , Hyperplasia , TechnologyABSTRACT
OBJECTIVES: To explore the experiences of patients with temporomandibular disorders (TMDs) with the National Health Service and to discover their healthcare priorities when seeking treatment. METHODS: Semi-structured interviews were used. They were directed using a topic guide covering subjects such as initial visits in primary care, referrals to secondary care, and the effect on symptoms. The discussions were audiotaped and transcribed verbatim. Thematic analysis was utilised to analyse the data. RESULTS: In total, 15 participants took part in three focus groups. Six themes were identified: "access to appropriate care", "organised and coordinated care", "receiving a diagnosis and enough information", "interaction with the clinical staff", "treatment strategies and having an 'action plan'" and "support and social networks". CONCLUSIONS: The participants gave accounts of the difficulties encountered in healthcare in general terms and specific to TMD. Most notable was the struggle to access appropriate care, receive a diagnosis and be understood. Our findings suggest that delays in delivering appointments with people of expertise may have caused the worsening of symptoms. However, when a pleasant experience was encountered, access to care was fast, the clinician was understanding and communication with the clinical team was good. These provided positive experiences and were appreciated by the patients.
Subject(s)
Chronic Pain , Temporomandibular Joint Disorders , Humans , State Medicine , Delivery of Health Care , Facial Pain/etiology , Facial Pain/therapy , Temporomandibular Joint Disorders/complications , Temporomandibular Joint Disorders/therapy , Chronic Pain/therapyABSTRACT
Ameloblastoma is a benign, locally invasive epithelial odontogenic neoplasm of the jaw. Treatment of choice is jaw resection, often resulting in significant morbidity. The aim of this study was to recapitulate ameloblastoma in a completely humanised 3D disease model containing ameloblastoma cells, osteoblasts and activated osteoclasts to investigate the RANKL pathway within the ameloblastoma stromal environment and its response to the RANKL antibody denosumab. In vitro bone was engineered by culturing human osteoblasts (hOB) in a biomimetic, dense collagen type I matrix, resulting in extensive mineral deposits by day 21 forming alizarin red positive bone like nodules throughout the 3D model. Activated TRAP + human osteoclasts were confirmed through the differentiation of human CD14+ monocytes after 10 days within the model. Lastly, the ameloblastoma cell lines AM-1 and AM-3 were incorporated into the 3D model. RANKL release was validated through TACE/ADAM17 activation chemically or through hOB co-culture. Denosumab treatment resulted in decreased osteoclast activation in the presence of hOB and ameloblastoma cells. These findings stress the importance of accurately modelling tumour and stromal populations as a preclinical testing platform.
ABSTRACT
Tumour development and progression is dependent upon tumour cell interaction with the tissue stroma. Bioengineering the tumour-stroma microenvironment (TME) into 3D biomimetic models is crucial to gain insight into tumour cell development and progression pathways and identify therapeutic targets. Ameloblastoma is a benign but locally aggressive epithelial odontogenic neoplasm that mainly occurs in the jawbone and can cause significant morbidity and sometimes death. The molecular mechanisms for ameloblastoma progression are poorly understood. A spatial model recapitulating the tumour and stroma was engineered to show that without a relevant stromal population, tumour invasion is quantitatively decreased. Where a relevant stroma was engineered in dense collagen populated by gingival fibroblasts, enhanced receptor activator of nuclear factor kappa-B ligand (RANKL) expression was observed and histopathological properties, including ameloblastoma tumour islands, developed and were quantified. Using human osteoblasts (bone stroma) further enhanced the biomimicry of ameloblastoma histopathological phenotypes. This work demonstrates the importance of the two key stromal populations, osteoblasts, and gingival fibroblasts, for accurate 3D biomimetic ameloblastoma modelling.
ABSTRACT
This series of articles comprise of short reviews of clinical problems relevant to oral health care in the twenty-first century. The present article uses a composite of presenting case symptoms to hypothetically illustrate differential diagnoses of pain of the tongue and why there may, or may not be, links to aspects of infection of SARS-CoV-2 (COVID-19).
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , TongueABSTRACT
Immune checkpoint inhibitors (ICIs) are a revolutionary class of antineoplastic therapy that restore anti-tumor immunity. Consequences of this enhanced immune response include a multitude of immune related adverse events (irAEs) that can affect any body system, including the mouth. Orofacial irAEs reproduce features of numerous immune-mediated conditions, including oral lichen planus, mucous membrane pemphigoid, and Sjögren syndrome, among others. The aim of this review is to summarize known orofacial irAEs and to familiarize oral healthcare providers with how to identify and manage these toxicities as part of the care team for patients treated with ICIs.
ABSTRACT
BACKGROUND: Oral lichen planus (OLP) is a chronic inflammatory disorder of the oral mucosa. Currently there is no approved treatment for OLP. We report on the efficacy and safety of a novel mucoadhesive clobetasol patch (Rivelin® -CLO) for the treatment of OLP. METHODS: Patients with confirmed OLP and measurable symptomatic ulcer(s) participated in a randomized, double-blind, placebo-controlled, multicenter clinical trial testing a novel mucoadhesive clobetasol patch (Rivelin® -CLO) in OLP across Europe, Canada, and the United States. Patients were randomized to placebo (nonmedicated), 1, 5, 20 µg Clobetasol/patch, twice daily, for 4 weeks. The primary endpoint was change in total ulcer area compared to baseline. Secondary endpoints included improvement from baseline in pain, disease activity, and quality of life. RESULTS: Data were analyzed and expressed as mean [SD]. One hundred thirty-eight patients were included in the study; 99 females and 39 males, mean age was 61.1 [11.6] years. Statistical analyses revealed that treatment with 20-µg Rivelin® -CLO patches demonstrated significant improvement with ulcer area (p = 0.047), symptom severity (p = 0.001), disease activity (p = 0.022), pain (p = 0.012), and quality of life (p = 0.003) as compared with placebo. Improvement in OLP symptoms from beginning to the end of the study was reported as very much better (best rating) in the 20-µg group (25/32) patients compared to the placebo group (11/30), (p = 0.012). Adverse events were mild/moderate. Candidiasis incidence was low (2%). CONCLUSIONS: Rivelin® -CLO patches were superior to placebo demonstrating statistically significant, clinically relevant efficacy in objective and subjective improvement and, with a favorable safety profile.
Subject(s)
Clobetasol , Lichen Planus, Oral , Administration, Topical , Clobetasol/adverse effects , Female , Glucocorticoids , Humans , Lichen Planus, Oral/drug therapy , Male , Middle Aged , Quality of LifeABSTRACT
OBJECTIVES: To validate the Visual Analog Scale (VAS) and Numerical Rating Scale (NRS) for measuring pain intensity in chronic oral mucosal diseases. METHODS: Secondary analyses of data including the VAS, NRS, demographic, clinical and quality-of-life outcomes at baseline and 4-month follow-up were retrieved from a clinical study of chronic oral mucosal diseases. Construct and criterion validity and responsiveness of the VAS and NRS were assessed through testing hypotheses based upon strength of Spearman's correlation coefficients. RESULTS: Data of 500 and 290 patients with chronic oral mucosal diseases were used for the assessment of validity and responsiveness, respectively. Moderate-to-high correlations between both pain scores and scores of clinical and quality-of-life outcomes were observed, supporting construct validity of the VAS and NRS. Their criterion validity was confirmed by significantly strong association between scores of both scales. Responsiveness of both scales was adequate based on moderate association between their change scores and global rating of change scale. CONCLUSION: The present results provide evidence supporting validity and responsiveness of the VAS and NRS for pain intensity assessment in patients with chronic oral mucosal diseases. Future research examining other pain intensity domains and standardizing composite scores for pain intensity in this population is required.
Subject(s)
Mouth Diseases , Pain , Humans , Mouth Diseases/diagnosis , Pain Measurement/methods , Quality of Life , Reproducibility of Results , Visual Analog ScaleABSTRACT
OBJECTIVE: To preliminary evaluate the clinical effects of probiotics in individuals with symptomatic oral lichen planus and the possible mechanisms of action. SUBJECTS AND METHODS: A group of 30 individuals with symptomatic oral lichen planus were recruited in a randomised double-blind parallel group controlled (1:1) proof-of-concept pilot trial of probiotic VSL#3 vs placebo. Efficacy outcomes included changes in pain numeric rating scale, oral disease severity score and the chronic oral mucosal disease questionnaire. Adverse effects, home diary and withdrawals were assessed as feasibility outcomes. Mechanistic outcomes included changes in salivary and serum levels of CXCL10 and IFN-γ and in oral microbial composition. RESULTS: The probiotic VSL#3 was safe and well tolerated. We observed no statistically significant change in pain, disease activity, quality of life, serum/salivary CXCL10 or oral microbial composition with respect to placebo. Salivary IFN-γ levels demonstrate a trend for a reduced level in the active group (p = 0.082) after 30 days of probiotic consumption. CONCLUSIONS: The present proof-of-concept study provides some weak not convincing indication of biological and clinical effects of probiotic VSL#3 in individuals with painful oral lichen planus. Further research in this field is needed, with the current study providing useful information to the design of future clinical trials.