Methylation of Immune Gene Promoters in Oral and Oropharyngeal Cancer.

The proportion of oral and oropharyngeal squamous cell carcinoma (OOSCC) that can be attributed to human papillomavirus (HPV) infection is growing nowadays. A potential factor indicating the occurrence of HPV-positive OSCC is a change in the degree of methylation of gene promoters that play a key role in the immune response. In this study, we investigated the difference in the methylation of EDARADD, GBP4, HAVCR2, HLA DPB1, IL12RB1, MARCO, and SIGLEC12 gene promoters in samples of healthy oral mucosa versus samples of oral and oropharyngeal cancer. The presence of HPV infection in samples was examined earlier. To determine the difference in methylation of those gene promotors, isolated and bisulfite-modified DNA was analysed by the methylation-specific PCR method. The investigated gene promoters were found to be more hypomethylated in the oral and oropharyngeal cancer samples in comparison to normal tissue. The proportion of unmethylated gene promoters was similar in HPV-positive and HPV-negative cancers, although the data should be confirmed on a larger set of samples. To conclude, in samples of healthy oral mucosa, the investigated gene promoters were found to be methylated in a high percentage (73.3% to 100%), while in oral and oropharyngeal cancer samples, they were methylated in a low percentage (11.1% to 37%), regardless of HPV infection.

B regulatory cells and monocyte subpopulations in patients with chronic graft-vs-host disease.

AIM: To assess the correlations of B regulatory cells (Bregs) and monocyte subsets in peripheral blood with the National Institutes of Health (NIH)-consensus-defined clinical manifestations of chronic graft-vs-host disease (cGvHD), in an attempt to establish their role as cellular biomarkers. METHODS: This multidisciplinary prospective study enrolled adult cGVHD patients treated in the University Hospital Center Zagreb and University of Zagreb School of Medicine. Immunophenotypic subpopulations of CD24highCD38high Bregs (CD27-, CD27+, and total) and monocyte (classical, intermediate, and non-classical) counts were correlated with demographic, transplant, and cGVHD-related data. Bivariate correlation analysis was performed to evaluate the correlations between Bregs and monocytes subsets and cGVHD organ involvement, as well as cGVHD severity and immunosuppression intensity. RESULTS: Twenty-two adult patients (54.5% female) with cGVHD were enrolled. The median (range) age was 44.5 years (24-65). All patients were transplanted for hematologic malignancies and 40.9% had severe NIH cGVHD global score. The median time from cGVHD diagnosis to the analysis was 16.6 months (0-176). The organ most frequently affected with cGVHD were the eyes (68.2%), skin (45.5%), lungs (45.5%), and liver (40.9%). Lower total and CD27-Bregs counts were correlated with worse cGVHD severity, higher immunosuppression intensity, and lung cGVHD, in terms of cell count, but also with skin cGVHD, in terms of percentages. Patients with liver and joint/fascia cGVHD had a lower percentage of non-classical monocytes and patients with more severe global NIH score had a higher classical monocytes count. CONCLUSION: Different organs affected by cGVHD are differently associated with different subpopulations of Bregs and monocytes.

Effects of Zeolite as a Drug Delivery System on Cancer Therapy: A Systematic Review.

Zeolites and zeolitic imidazolate frameworks (ZIFs) are widely studied as drug carrying nanoplatforms to enhance the specificity and efficacy of traditional anticancer drugs. At present, there is no other systematic review that assesses the potency of zeolites/ZIFs as anticancer drug carriers. Due to the porous nature and inherent pH-sensitive properties of zeolites/ZIFs, the compounds can entrap and selectively release anticancer drugs into the acidic tumor microenvironment. Therefore, it is valuable to provide a comprehensive overview of available evidence on the topic to identify the benefits of the compound as well as potential gaps in knowledge. The purpose of this study was to evaluate the potential therapeutic applications of zeolites/ZIFs as drug delivery systems delivering doxorubicin (DOX), 5-fluorouracil (5-FU), curcumin, cisplatin, and miR-34a. Following PRISMA guidelines, an exhaustive search of PubMed, Scopus, Embase, and Web of Science was conducted. No language or time limitations were used up to 25th August 2021. Only full text articles were selected that pertained to the usage of zeolites/ZIFs in delivering anticancer drugs. Initially, 1279 studies were identified, of which 572 duplicate records were excluded. After screening for the title, abstract, and full texts, 53 articles remained and were included in the qualitative synthesis. An Inter-Rater Reliability (IRR) test, which included a percent user agreement and reliability percent, was conducted for the 53 articles. The included studies suggest that anticancer drug-incorporated zeolites/ZIFs can be used as alternative treatment options to enhance the efficacy of cancer treatment by mitigating the drawbacks of drugs under conventional treatment.

ASSESSMENT OF ALLERGIES TO FOOD AND ADDITIVES IN PATIENTS WITH ANGIOEDEMA, BURNING MOUTH SYNDROME, CHEILITIS, GINGIVOSTOMATITIS, ORAL LICHENOID REACTIONS, AND PERIORAL DERMATITIS.

Oral cavity and perioral area are constantly exposed to a variety of antigens, including food and additives, which have a potential role in the development of different oral mucosal and perioral cutaneous diseases since they can cause hypersensitivity reactions. Oral and perioral diseases mainly include angioedema, burning mouth syndrome, cheilitis, gingivostomatitis, oral lichenoid reactions, and perioral dermatitis. Previous studies were focused on delayed-type oral allergies by performing patch testing but did not include tests for immediate-type allergic reactions. Therefore, the objective of this study was to determine common nutritive and additive allergens in the prevalent oral and perioral diseases by using skin prick tests. Our study evaluated 230 participants, i.e. 180 patients with oral/perioral diseases (angioedema, burning mouth syndrome, cheilitis, gingivostomatitis, oral lichenoid reactions, and perioral dermatitis), and 50 healthy control subjects. The results of skin prick tests showed that immediate-type allergic reactions to food and additives were mostly seen in patients with burning mouth syndrome (40%) and cheilitis (33.3%), whereas allergies were least frequently observed in perioral dermatitis (10%) and gingivostomatitis (20%). Fruits, mushrooms, and vegetables were the most frequent causes of nutritive allergies in oral and perioral diseases. The most commonly identified additive allergens were glutaraldehyde, citric acid, and sodium glutamate. Study results suggest the possible association with nutritive and additive allergies be considered in cases of persistent oral mucosal or perioral skin disease accompanied by respective medical history.

DNA Methylome Distinguishes Head and Neck Cancer from Potentially Malignant Oral Lesions and Healthy Oral Mucosa.

There is a strong need to find new, good biomarkers of head and neck squamous cell carcinoma (HNSCC) because of the bad prognoses and high mortality rates. The aim of this study was to identify the potential biomarkers in HNSCC that have differences in their DNA methylome and potentially premalignant oral lesions, in comparison to healthy oral mucosa. In this study, 32 oral samples were tested: nine healthy oral mucosae, 13 HNSCC, and 10 oral lesions for DNA methylation by the Infinium MethylationEPIC BeadChip. Our findings showed that a panel of genes significantly hypermethylated in their promoters or specific sites in HNSCC samples in comparison to healthy oral samples, which are mainly oncogenes, receptor, and transcription factor genes, or genes included in cell cycle, transformation, apoptosis, and autophagy. A group of hypomethylated genes in HNSCC, in comparison to healthy oral mucosa, are mainly involved in the host immune response and transcriptional regulation. The results also showed significant differences in gene methylation between HNSCC and potentially premalignant oral lesions, as well as differently methylated genes that discriminate between oral lesions and healthy mucosa. The given methylation panels point to novel potential biomarkers for early diagnostics of HNSCC, as well as potentially premalignant oral lesions.

COMMON ALLERGIES AND ALLERGENS IN ORAL AND PERIORAL DISEASES.

Allergic reactions sometimes participate in the development of perioral and oral diseases, indicating the need for appropriate allergen assessment. This review discusses current knowledge on the potential allergic reactions to different dental materials in patients with oral and perioral diseases. Aside from allergies to various dental materials, similar non-allergic, non-immune contact reactions (irritant or toxic) can occur. Among dental materials, the most frequent allergens are alloys, followed by rubber materials, polymers and acrylates. Allergic reactions to dental alloys that contain nickel, cobalt and amalgam are especially frequent since dentists use them for prosthetic and other restorations. There is a broad spectrum of clinical presentations of oral and perioral diseases possibly related to allergies, such as lichenoid reactions, cheilitis, perioral dermatitis, burning sensations, etc. Despite some limitations, patch test is crucial in the diagnosis and recognition of causative allergens because it reveals contact allergies, and is still superior in differentiating allergic and irritant contact reactions. It is important to examine patient medical histories (e.g., occurrence of symptoms after dental therapy or food consumption), and in consultation with their dentist, carry out allergy tests to specific dental allergens which are used or planned to be used in subsequent treatment.

Autologous blood as a source of platelet gel for the effective and safe treatment of oral chronic graft-versus-host disease.

BACKGROUND: Oral chronic graft-versus-host disease (cGvHD) impairs oral function and patients' quality of life. Some lesions are refractory to local and systemic immunosuppressive therapy, and new therapeutic modalities are required. The aim of the study was to assess the efficacy and safety of topical application of autologous platelet gel (PG) in patients with oral cGvHD. STUDY DESIGN AND METHODS: PG was prepared from autologous blood and applied on ulcerous lesions using an automated system. The oral cGvHD was assessed using the 273-point Oral Mucositis Rating Scale (OMRS) prior and after completion of the PG treatment. The overall response to treatment of particular topography expressed as the total score on OMRS was compared to total score on National Institutes of Health cGvHD Oral Mucosal Score (NIH OMS). The pain intensity was measured by the Numeric Pain Rating Scale (NRS). RESULTS: In five patients, 12 autologous blood collections were performed; median 3 (range 1-3) per patient, and 26 PG applications were performed; median 6 (range 2-8) per patient. PG applications reduced lesions in oral cGvHD: median OMRS total score was reduced for 43.2% (range 9.6%-47.3%), and median NIH OMS total score for 27.3% (range 20.0%-50.0%) from baseline values. Median of pain intensity reduction on NRS scale was 57.1% (range 50%-100%). No side effects were observed. CONCLUSION: Application of autologous PG in oral cGvHD showed as an efficient and safe treatment option for patients who do not respond to standard local treatment.

Expression of small leucine-rich extracellular matrix proteoglycans biglycan and lumican reveals oral lichen planus malignant potential.

OBJECTIVES: The aim of this study was to examine molecular alterations on the protein level in lesions of oral lichen planus (OLP), oral squamous cell carcinoma (OSCC) and healthy mucosa. MATERIALS AND METHODS: Global protein profiling methods based on liquid chromatography coupled to mass spectrometry (LC-MS) were used, with a special emphasis on evaluation of deregulated extracellular matrix molecules expression, as well as on analyses of IG2F and IGFR2 expression in healthy mucosa, OLP and OSCC tissues by comparative semi-quantitative immunohistochemistry. RESULTS: Mass spectrometry-based proteomics profiling of healthy mucosa, OLP and OSCC tissues (and accompanied histologically unaltered tissues, respectively) identified 55 extracellular matrix proteins. Twenty among identified proteins were common to all groups of samples. Expression of small leucine-rich extracellular matrix proteoglycans lumican and biglycan was found both in OSCC and OLP and they were validated by Western blot analysis as putative biomarkers. A significant increase (p < 0.05) of biglycan expression in OLP-AT group was determined in comparison with OLP-T group, while lumican showed significant up-regulation (p < 0.05) in OLP-T and OSCC-T groups vs. adjacent and control tissue groups. Biglycan expression was only determined in OSCC-AT group. Immunohistochemical analysis of IGF2 and IG2FR expression revealed no significant difference among groups of samples. CONCLUSION/CLINICAL RELEVANCE: Biglycan and lumican were identified as important pathogenesis biomarkers of OLP that point to its malignant potential.

High frequency of cutaneous manifestations including vitiligo and alopecia areata in a prospective cohort of patients with chronic graft-vs-host disease.

AIM: To determine the frequency and the characteristics of cutaneous manifestations, especially vitiligo and alopecia areata, in patients with chronic graft-vs-host disease (cGVHD). METHODS: 50 patients with cGVHD were prospectively enrolled in the observational study protocol and evaluated by an experienced dermatologist. The evaluation was focused on the clinical spectrum of skin and adnexal involvement, and the cutaneous GVHD score was determined according to National Institutes of Health (NIH) Consensus criteria. The presence of vitiligo, alopecia, xerosis, nail changes, and dyspigmentation was also assessed. RESULTS: Out of 50 cGVHD patients, 28 (56%) had skin involvement, and 27 of them (96%) had hypo and/or hyperpigmentations. 11 patients (39%) had a mild cutaneous NIH cGVHD score, 22% moderate, and 39% severe. 15 (30%) patients had nail changes and 10 (20%) had vitiligo or alopecia areata. Univariate analysis showed that patients with vitiligo/alopecia areata received more lines of prior systemic immunosuppressive therapy (P=0.043), had lower Karnofsky performance status (P=0.028), and had a higher B-cell number (P=0.005), platelet count (P=0.022), and total protein (P=0.024). Vitiligo and alopecia areata were associated with higher NIH skin score (P=0.001), higher intensity of immunosuppressive treatment (P=0.020), and total body irradiation conditioning (P=0.040). Multivariate regression model showed that patients with higher NIH skin scoring were 3.67 times more likely to have alopecia and/or vitiligo (odds ratio 3.67; 95% confidence interval 1.26-10.73), controlled for all other factors in the model (age at study entry, number of B-cells, platelet count, and global NIH score). CONCLUSION: These data indicate that vitiligo and alopecia areata occur more frequently in cGVHD than previously reported.

Clinicopathologic correlation of oral lichen planus and oral lichenoid lesions: a preliminary study.

Oral lichen planus (OLP) and oral lichenoid lesions (OLL) are clinically and histologically similar lesions but their treatment planning and prognosis are different. The review of the literature indicates numerous criteria to distinguish these two lesions; however there is a lot of inconsistency. Thus, the aim of this study was to determine the correlation of histopathology and clinical OLP and OLL diagnosis and to clarify which histopathologic criteria could best distinguish these two diagnoses. A retrospective study showed that clinically diagnosed 92 OLPs and 14 OLLs have been confirmed histopathologically in 52.2% and 42.9% of cases, respectively. In addition, histopathology showed statistically significant more eosinophils (P<0.0005), plasma cells (P<0.0005), and granulocytes (P<0.05) in OLL than OLP. To establish histopathological diagnosis of OLP and OLL it should be mandatory to define the type of cells in mononuclear infiltrate, which can be associated more accurately with clinical feature and patient history. Therefore, currently accepted diagnostic criteria for OLP and OLL should be modified and validated on a larger number of patients taking into account particular distinguishing histopathological features.

The frequency and malignant transformation rate of oral lichen planus and leukoplakia--a retrospective study.

The aim of this retrospective study was to determine the frequency and malignant transformation rate of oral lichen planus and leukoplakia in a large group of oral medicine patients. Study included 12 508 patients who were referred between 1998 and 2007 to the Department of Oral Medicine. The frequency of OLP was 4.30%, leukoplakia 1.11%, and combined diagnoses 0.14%. In primary biopsies dysplasia was found in 12.96% of patients with leukoplakia and not in one with OLP and combined lesions. The highest frequency of leukoplakia was found in smokers. Women were found as predominant sufferers of both diseases and their combination. During the observed period often years malignant transformation of OLP was not detected, unlike leukoplakia where it was 0.64%. The frequency of OLP and leukoplakia in our study are comparable to other similar studies. The highest frequency of malignant transformation was observed in those patients who did not respond to our invitation to regular check-up. It is therefore neccessary to perform a detailed examination of the oral cavity in these patients and to raise patients awareness of the disease and the importance of regular follow-up.

Salivary Scca1, Scca2 and Trop2 in Oral Cancer Patients-A Cross-Sectional Pilot Study.

Oral squamous cell carcinoma (OSCC) is frequently diagnosed in the advanced stages. The purpose of this paper is to determine the salivary values of SCCA1, SCCA2 and TROP2 in patients with T1N0M0 OSCC and to compare them with the values obtained from healthy individuals. Unstimulated (UWS) and stimulated (SWS) saliva was sampled from 29 patients with T1N0M0 OSCC and 29 sex- and age-matched healthy individuals. Statistical difference was observed in SCCA1 and SCCA2 levels both in UWS and SWS samples. TROP2 was not measurable in most of the salivary samples. Both SCCA1 and SCCA2 could represent potential biomarkers for the early-stage OSCC. Research on a larger sample and biomarker validation is needed to assess the clinical potential of SCCA1 and SCCA2 in the OSCC early diagnostics.

Oral mucosal lesions during orthodontic treatment.

BACKGROUND: Oral mucosal lesions can result from irritation caused by orthodontic appliances or malocclusion, but their frequency is not known. AIM: To examine the frequency of oral mucosal lesions in wearers of orthodontic appliances in comparison to children with malocclusion. DESIGN: This study comprised 111 subjects: 60 wearers of orthodontic appliances and 51 controls (aged between 6 and 18 years). Type and severity of mucosal lesions, their topography, gingival inflammation, and oral hygiene status were determined by using clinical indices. RESULTS: Mucosal lesions were more present in wearers of orthodontic appliances than in children with malocclusion. Gingival inflammation, erosion, ulceration, and contusion were the most common findings in orthodontic patients. The severity of gingival inflammation was in correlation with oral hygiene status; the poorer oral hygiene, the more severe gingival inflammation was. Better oral hygiene status was found in children during orthodontic treatment than in children with malocclusion. CONCLUSIONS: Orthodontic treatment carries a higher risk of mucosal lesions and implies greater awareness of better oral hygiene as shown by the results of this study. Oral hygiene instructions and early treatment of oral lesions are important considerations in better patient's motivation, treatment planning, and successful outcome.

Features of the Skin Microbiota in Common Inflammatory Skin Diseases.

Many relatively common chronic inflammatory skin diseases manifest on the face (seborrheic dermatitis, rosacea, acne, perioral/periorificial dermatitis, periocular dermatitis, etc.), thereby significantly impairing patient appearance and quality of life. Given the yet unexplained pathogenesis and numerous factors involved, these diseases often present therapeutic challenges. The term "microbiome" comprises the totality of microorganisms (microbiota), their genomes, and environmental factors in a particular environment. Changes in human skin microbiota composition and/or functionality are believed to trigger immune dysregulation, and consequently an inflammatory response, thereby playing a potentially significant role in the clinical manifestations and treatment of these diseases. Although cultivation methods have traditionally been used in studies of bacterial microbiome species, a large number of bacterial strains cannot be grown in the laboratory. Since standard culture-dependent methods detect fewer than 1% of all bacterial species, a metagenomic approach could be used to detect bacteria that cannot be cultivated. The skin microbiome exhibits spatial distribution associated with the microenvironment (sebaceous, moist, and dry areas). However, although disturbance of the skin microbiome can lead to a number of pathological conditions and diseases, it is still not clear whether skin diseases result from change in the microbiome or cause such a change. Thus far, the skin microbiome has been studied in atopic dermatitis, seborrheic dermatitis, psoriasis, acne, and rosacea. Studies on the possible association between changes in the microbiome and their association with skin diseases have improved the understanding of disease development, diagnostics, and therapeutics. The identification of the bacterial markers associated with particular inflammatory skin diseases would significantly accelerate the diagnostics and reduce treatment costs. Microbiota research and determination could facilitate the identification of potential causes of skin diseases that cannot be detected by simpler methods, thereby contributing to the design and development of more effective therapies.

Diagnostic management of cheilitis: an approach based on a recent proposal for cheilitis classification.

Currently, there are no clear recommendations for diagnostic management of lip inflammation and cheilitis, which is evident in the varied nomenclature and subtypes found in medical literature on cheilitis. This can confound diagnostic management. We therefore recently put forth a proposal for cheilitis classification, defining three groups of cheilitis based on duration and etiology: mainly reversible cheilitis, mainly irreversible cheilitis, and cheilitis connected to other diseases. The most common forms of cheilitis are the reversible types, usually of short duration and commonly easily resolved or treated. In contrast, irreversible types of cheilitis are rare, are harder to treat, and are confirmed only after a biopsy of an inflamed lesion. To correctly diagnose and manage the different types, practitioners must consider several factors, including visible manifestations of the disease, related diseases and symptoms, personal habits, weather conditions, allergies, nutritional deficiencies, and results from tissue swabs and biopsies. In addition, multispecialty collaboration and communication involving dermatology, oral pathology, clinical immunology, otorhinolaryngology, rheumatology, and other fields can be crucial for patient outcome. We believe our classification system would be of great benefit to researchers, patients, and doctors by simplifying both nomenclature and disease recognition, thus ensuring timely and adequate treatment.

Oral lichen planus: a retrospective comparative study between Thai and Croatian patients.

Oral lichen planus (OLP) is a common oral mucosal disease that affects middle age patients. However, there are few reports about the incidence of OLP in different ethnic groups. The purpose of this study was to compare the characteristics of OLP in Thai and Croatian patients. Retrospective data were taken from medical records of 175 patients referred to the Oral Medicine Department of Chulalongkorn University and 175 patients referred to the School of Dental Medicine, University of Zagreb during the 1997-2007 period. In all patients the diagnosis of OLP was clinically and histopathologically confirmed. In Thai and Croatian OLP patients, females were predominant (the female to male ratio was 3.5:1). Croatian OLP patients were older with a significant age difference between female Thai and Croatian OLP patients (p<0.05). Atrophic-erosive type of OLP was common in Thai patients, whereas reticular OLP was predominant in Croatians (p<0.001). Burning sensation was the most common chief complaint in both ethnic groups. Significant differences between the two ethnic groups were found in the sites of OLP lesions as well as in the occurrence of pain, roughness and white patches, systemic diseases and use of medication (p<0.05). Croatian patients had more systemic diseases and took more medications than Thai. Three cases showed dysplasia in either group, whereas only one Thai patient developed squamous cell carcinoma. Although Thai and Croatian patients differed significantly according to the clinical type of OLP, the rate of malignant transformation was very low.

Gingival Papillomatosis as the Oral Sign of Cowden Syndrome: A Case Report.

Cowden syndrome (CS) is a rare autosomal dominant, hereditary, multiorgan disease with higher risk for malignancies (breast, thyroid, endometrium). Mucocutaneous lesions occur in 90% of cases and are characterized by facial trichilemmomas, oral mucosal papillomas, and benign acral keratoses. We present the case of a 39-year-old female patient with the chief complaint of "white spots" on the upper and lower attached gingiva accompanied with skin changes on the face, hands, and soles. The patient's family medical history revealed that her mother had an endometrial polyp and the sister had thyroid cancer. In the patient's medical personal history she reported follicular thyroid adenoma, thyroid abnormalities (i.e. lymphocytic thyroiditis), fibrocystic changes and juvenile breast papillomatosis, lipoma, multiple fibromas, and genitourinary tumors. Based on extensive family and personal medical history, physical examination and histopathological findings, diagnostic criteria were fulfilled for the diagnosis of Cowden syndrome.

Oral acanthosis nigricans: case report and comparison with literature reports.

Acanthosis nigricans (AN) is a rare condition which may affect oral cavity. There are two forms of AN: benign and malignant. Benign AN may be hereditary, or may be related to systemic diseases or drugs. Malignant AN is most often associated with gastric adenocarcinoma but cancers of other sites and types may also occur. This case report is based on a case of a 78-year-old woman suffering from invasive bladder papillary transitional cell carcinoma accompanied by extensive papillomatous areas of normal mucosal color and soft consistency involving the lips, buccal mucosa and hard palate. Verrucous changes with tiny pigmented macules were also found on the skin of the right ear auricle. Oral lesions occurred after the tumor had been diagnosed, i.e. after third operation for tumor recurrence. The fifth operation for tumor recurrence resulted in slight improvement of oral changes. It is concluded that the severity of oral changes is in correlation with tumor progression. The occurrence of oral lesions may be an indicator of tumor progression.

Knowledge of Oral Cancer among the Fourth and Fifth Year Dental Students.

BACKGROUND: The literature data show insufficient knowledge and awareness about oral cancer among dental and medical students. OBJECTIVE: To assess the knowledge of graduating dental students regarding oral cancer and to assess their awareness regarding the prevention and early detection of oral cancer. Also student's smoking status was examined aimed to investigate their attitude towards smoking as a risk factor for development of oral cancer and to assess the prevalence of smoking among dental students. SUBJECTS AND METHODS: The study group consisted of 83 students of the fourth and fifth years of dental medicine study who answered the questions written in the original 16-item questionnaire. RESULTS: More than half of the students considered their knowledge to be good, a quarter of them regarded their knowledge as being poor. Almost 16% of students considered their knowledge to be very good, whereas only two students rated their knowledge as 'excellent'. Students of the fifth year were more likely to be smokers compared to fourth year students (39.5% vs. 22.5%). Higher percentage of non-smokers than smokers had marked 'stop smoking' as an important preventive measure (non-smokers 91.2%, smokers 84.3%, p = 0.01). CONCLUSION: Majority of the students of fourth and fifth year of study rate their knowledge about oral cancer as good. A large number of students of both years considered hairy leukoplakia a potentially malignant disorder. Students non smokers recognize "stop smoking" as an important preventive measure unlike students smokers who show a more realistic attitude towards smoking as a risk factor for oral cancer.