Comparative clinicopathological study of the main anatomic locations of oral squamous cell carcinoma.

OBJECTIVE: To analyze the clinicopathological and evolutionary profile of the main locations of oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: This is a retrospective study on 133 patients treated for OSCC. The group was composed of 48 women and 85 men, with a mean age 63.9 ± 12.73 years. Most cases involved the lingual border of tongue (63), followed by the gingiva (36) and the floor of mouth (34). A comparative analysis was performed using multinomial regression. RESULTS: There were significant differences regarding age, sex, tobacco and alcohol consumption, liver pathology, oral potentially malignant disorders, and bone and perineural invasion. In multivariate regression, tobacco consumption, and bone invasion remained significant. There were no significant differences in relation to prognosis. CONCLUSION: The location of OSCC is an important factor in the clinicopathological assessment of this neoplasm. The main locations of OSCC show differential etiopathogenic and clinicopathological aspects. Tobacco consumption has a great relevance in the floor of mouth; nonetheless, it is less important in the tongue border and the gum, which suggests other pathogenic factors. It is necessary to consider the anatomical location of OSCC in preventive protocols, with the aim of reducing its high mortality.

Identification of Proteomic Biomarkers in Proliferative Verrucous Leukoplakia through Liquid Chromatography With Tandem Mass Spectrometry.

Proliferative verrucous leukoplakia (PVL) is an oral potentially malignant disorder associated with high risk of malignant transformation. Currently, there is no treatment available, and restrictive follow-up of patients is crucial for a better prognosis. Oral leukoplakia (OL) shares some clinical and microscopic features with PVL but exhibits different clinical manifestations and a lower rate of malignant transformation. This study aimed to investigate the proteomic profile of PVL in tissue and saliva samples to identify potential diagnostic biomarkers with therapeutic implications. Tissue and saliva samples obtained from patients with PVL were compared with those from patients with oral OL and controls. Label-free liquid chromatography with tandem mass spectrometry was employed, followed by qualitative and quantitative analyses, to identify differentially expressed proteins. Potential biomarkers were identified and further validated using immunohistochemistry. Staining intensity scan analyses were performed on tissue samples from patients with PVL, patients with OL, and controls from Brazil, Spain, and Finland. The study revealed differences in the immune system, cell cycle, DNA regulation, apoptosis pathways, and the whole proteome of PVL samples. In addition, liquid chromatography with tandem mass spectrometry analyses showed that calreticulin (CALR), receptor of activated protein C kinase 1 (RACK1), and 14-3-3 Tau-protein (YWHAQ) were highly expressed in PVL samples. Immunohistochemistry validation confirmed increased CARL expression in PVL compared with OL. Conversely, RACK1 and YWHA were highly expressed in oral potentially malignant disorder compared to the control group. Furthermore, significant differences in CALR and RACK1 expression were observed in the OL group when comparing samples with and without oral epithelial dysplasia, unlike the PVL. This research provides insights into the molecular mechanisms underlying these conditions and highlights potential targets for future diagnostic and therapeutic approaches.

Photobiomodulation in dental implant stability and post-surgical healing and inflammation. A randomised double-blind study.

BACKGROUND: The aim of this randomized clinical trial was to evaluate the effect of diode laser photobiomodulation (PBM) on post-surgical healing, inflammation and implant stability. METHODS: Forty dental implants were inserted into 13 patients. The implants were randomly divided into two groups. The test group (PBM+) underwent two sessions of PBM (combined diode laser of 630 and 808 nm), the first of which after surgery, and the second, 7 days after the surgical procedure. The control group (PBM-) received simulated laser treatment. The implant stability quotient (ISQ) was determined immediately after the surgical procedure, and 7 days, 4 and 8 weeks later. Post-surgical inflammation was assessed following the criteria described by Bloemen and Cols. Healing was calculated using the healing index (HI). RESULTS: No differences were found in terms of the mean values of implant stability between the test and control groups over time. Only two of the implants (18.2%) from the PBM- group were classified with the maximum healing index (HI = 5), whereas in the PBM+ group, nine implants (45%) were classified with the aforementioned index (P < 0.0001). Using the logistic regression, it was determined that the non-application of the laser in the PBM- group caused an OR of 4.333 times of presenting inflammation (IC95% 1.150-16.323; P = 0.030). CONCLUSIONS: The application of 808 nm infra-red laser for bone tissue, and 630 nm for mucosal tissue in two sessions is considered to be an effective way of reducing inflammation and improving early healing. More studies are needed to confirm these results.

Importance of the vaporization margin during CO2 laser treatment of oral leukoplakia: A survival study.

OBJECTIVES: The main purpose of this study was to assess the response of oral leukoplakia to CO2 laser vaporization treatment, as well as determining possible factors that may affect recurrence of lesions. MATERIALS AND METHODS: A retrospective study was conducted, in which the medical records of patients who had been clinically and histologically diagnosed with oral leukoplakia and treated with CO2 laser between 1996 and 2019 at the Oral Medicine Teaching Unit of the Faculty of Dentistry of the University of Santiago de Compostela were reviewed. RESULTS: Fifty-eight patients were included: 36 female and 22 male subjects, with a mean age of 63.7 years old (SD ±13.1). The average follow-up time was 57.5 months (SD ±57.9). A relapse rate of 52.6% was determined. Of all the studied variables, the margin was the only one for which a statistically significant association with recurrence of lesions was demonstrated (p < 0.05). CONCLUSION: The vaporization of lesions using CO2 laser with a safety margin of at least 3 mm from the clinical limits of OL is a key factor in preventing recurrence.

Bleeding during tooth extraction in patients with chronic kidney disease: A cross-sectional pilot study.

OBJECTIVE: This work measures the intra-operative bleeding in end-stage renal disease patients and assesses whether laboratory coagulation tests and nitrogenous compounds are related to a higher bleeding risk. METHODS: Laboratory tests were performed on the day of surgery and some patients with thrombocytopenia and values above the normal levels of international normalised ratio (INR), thrombin time (TT) and activated partial thromboplastin time (aPTT) were identified. RESULTS: Haemostatic time ranged from 2 to 35 min (mean of 8.51 min) after suture. Bleeding volume ranged from 0.02 to 67.06 mL (mean of 4.38 mL) and the bleeding volume per minute ranged from 0.05 to 2.10 mL/min (median of 0.6 mL/min). Only seven patients (16.27%) had abnormal bleeding (more than 0.6 mL/min). Spearman's coefficient showed weak correlations between bleeding volume (mL/min) and serum urea (r = 0.226), TT (r = 0.227), plasma urea (r = 0.148) and creatinine (r = 146), as well as very weak correlations with all other variables (r < 0.140) such as age, haemodialysis time, glycaemia, glycated haemoglobin, platelets, INR, aPTT and fibrinogen. CONCLUSION: It was not possible to associate any laboratory test or nitrogenous compounds present in the blood and saliva with an increased bleeding.

Drug use, risk perceptions and attitudes towards drug use amongst medical and dentistry students.

AIMS: To analyse the use of psychoactive substances and the risk perceptions amongst odontology and medical students. To study their perceptions, attitudes and knowledge, and to evaluate their motivation when helping their patients to stop using these substances. METHODS: A cross-sectional study was conducted amongst 962 students in Spain, using validated questionnaires on an anonymous basis. RESULTS: Amongst these students, drug use varies and increases with age as assessed by the DAST and CAST tests, with more problematic use being observed as the academic cycle progresses (p < .001). Participants in the 2nd cycle presented higher consumption than those in the 1st cycle, in the univariate model (OR = 1.77, IC 95% 1.27-2.48, p = .001) and in the adjusted model (OR = 1.86, IC 95% 1.32-2.62, p < .001). Regarding CAST, non-problematic use in the 1st cycle versus the 3rd cycle presented an OR = 8.69 (IC 95% 4.50-16.78, p < .001) and for low risk use it presented an OR = 15.18 (IC 95% 1.83-14.68). Only 46.7% considered using marijuana on a regular basis as a high risk, whilst 60.5% stated that smoking a pack of cigarettes represents a high risk. Alcohol was the substance for which the risk perception was lowest. 66.2% are in the maintenance stage "I provide my regular drug-using patients help to give up," with women being more likely to be in this stage (p = .012). CONCLUSIONS: High risk of drug use increases after the 1st cycle in Dentistry and in Medicine. Training programmes should be implemented in both degrees, focusing on the 1st years in order to simultaneously prevent drug use amongst students.

Lichenoid areas may arise in early stages of proliferative verrucous leukoplakia: A long-term study of 34 patients.

BACKGROUND: Proliferative verrucous leukoplakia is considered an uncommon oral potentially malignant disorder with a high malignant transformation rate. The objective of this paper was to define its cancer incidence and related risk factors. METHODS: A retrospective audit of 34 patients diagnosed with proliferative verrucous leukoplakia from a university-based unit, during the period from 1995 to 2019 was performed. The mean number of visits was 23 ± 18.6. The follow-up was divided into four-time intervals to evaluate the clinical presentation, number of lesions, dysplasia grade, and malignant transformation rate. RESULTS: The majority of patients were females 29 (85.3%), with verrucous component (77.8%), with a gingival presentation (31.8%), and with a preceding lichenoid area (44.1%). Eleven patients (32.4%) were affected by oral cancer during the follow-up, developing a total of 15 carcinomas. The mean age of malignant transformation was 67.2 ± 12.9 years, particularly 8 ± 8.5 from the onset of the lesions. Warty forms presented a higher mean estimate for malignant transformation (15.2 years, 95% confidence interval 4.4-26 years) than nodular forms (1.9 years, 95% confidence interval 1.9-1.9) (p = 0.019). Patients with an initial proliferative verrucous leukoplakia diagnosis suffered a higher risk of malignancy, particularly 15.55 times (95% confidence interval 1.69-143.17; p = 0.015) than those who did present a preceding area with lichenoid morphology. CONCLUSION: Proliferative verrucous leukoplakia presented a high malignant transformation rate and sometimes displayed preceding oral lichenoid areas in early stages. Further studies are needed to understand the impact of these lichenoid areas in proliferative verrucous leukoplakia progression.

Critical update, systematic review, and meta-analysis of oral erythroplakia as an oral potentially malignant disorder.

BACKGROUND: Oral erythroplakia has been classically considered as the potentially malignant disorder with the highest rate of malignant development into squamous cell carcinoma. This critical systematic review and meta-analysis aim to estimate the malignant development rate of oral erythroplakia and identify the associated risk factors. METHODS: We performed a bibliographic search in PubMed, Scopus, Web of Science, Embase, and LILACS, with keywords "erythroplakia," "erythroplasia," "malignant transformation," "malignant development," "malignization," "carcinogenesis," "oral cancer," "oral squamous cell carcinoma," "mouth neoplasm," and "prognosis." Meta-analysis was conducted using a random-effects model. RESULTS: Ten observational studies with 441 patients met the inclusion criteria, whose mean malignant development rate was 12.7% and with a mean follow-up period of patients of 6.66 years. In the initial biopsy, 42.8% of oral erythroplakia were already squamous cell carcinoma. The buccal mucosa was the most frequent location of oral erythroplakia, but the floor of the mouth was the most common site of malignant development. All patients who underwent malignant development showed epithelial dysplasia on the initial diagnostic biopsy. CONCLUSION: Overall malignant development rate of OE in the meta-analysis was 19.9%. We could not associate any specific clinicopathological feature with the malignant development. The presence of epithelial dysplasia in the initial biopsy remains the worst prognostic factor. Further observational studies on OE are needed, with well-established diagnostic criteria and good clinical follow-up, in order to identify the true risk of malignant development of oral erythroplakia and the related risk factors.

Malignant development of proliferative verrucous/multifocal leukoplakia: A critical systematic review, meta-analysis and proposal of diagnostic criteria.

BACKGROUND: Proliferative verrucous/multifocal leukoplakia (PVML) is an oral potentially malignant disorder (OPMD) that exhibits high rates of malignant development (MD). This study aimed to analyse the risk of MD of PVML, as well as to investigate the possible risk factors associated with its malignization. METHODS: A bibliographical search of the PubMed, Embase, Web of Science, and Scopus databases was conducted. PVML MD rates were calculated as a pooled proportion, and the risk factors were calculated as risk ratios, using fixed and random models based on the presence of heterogeneity. RESULTS: From a total of 417 records, 16 articles were retrieved for inclusion. The subgroup analysis revealed a higher MD rate in the studies that were conducted in America, and, likewise, said studies involved a longer follow-up time (>6 years). There was a non-significant lower risk of malignization among males. A negative correlation was observed between MD and the year in which the studies were published. CONCLUSIONS: The pooled MD of PVML was 65.8% (95% CI: 55.3-76.2, p < 0.001). Prospective studies of PVML must be designed using simple and universal clinical diagnostic criteria to be able to make an early diagnosis of this important OPMD and acknowledge the frequency of MD.

Xerostomia, the perception of general and oral health and health risk behaviours in people over 65 years of age.

BACKGROUND: This study investigated the association between xerostomia and health risk behaviours, general and oral health and quality of life. METHODS: A cross-sectional study involving 800 adults over 65 years of age residing in Spain using a computer-assisted telephone questionnaire. The severity of xerostomia was assessed through the Xerostomia Inventory (XI). Both univariate and adjusted multinomial logistic regression were used to determine the risk (OR) of xerostomia. RESULTS: The sample comprised of 492 females (61.5%) and 308 males, with a mean age of 73.7 ± 5.8 years. Some, 30.7% had xerostomia: 25.6% mild, 4.8% moderate and 0.3% severe, the majority being female (34.8% vs 24%; p = 0.003). The mean XI was 24.6 ± 6.3 (95% CI 19.2-24.8) for those with poor health, whereas it was 17.4 ± 6.3 (95%CI 16.1-18.6) in those reporting very good health (p < 0.001). This difference was also observed in terms of oral health, with the XI mean recorded as 14.7 ± 10.7 for very poor oral health and 6.4 ± 5.4 for those with very good health (p = 0.002). Logistic regression showed that the highest OR for xerostomia was observed among adults with poor general health (2.81; 95%CI 1.8-4.3; p < 0.001) and for adjusted model the OR was still significant (2.18; 95%CI 1.4-3.4; p = 0.001). Those who needed help with household chores had 2.16 higher OR (95%CI 1.4-3.4; p = 0.001) and 1.69 (95%CI 1.1-2.7; p = 0.03) in the adjusted model. Females had a higher risk of suffering from xerostomia than males. CONCLUSION: The strong association between xerostomia and the general and oral health status of older adults justifies the need for early assessment and regular follow-up.

Efficacy of photobiomodulation in reducing pain and improving the quality of life in patients with idiopathic burning mouth syndrome. A systematic review and meta-analysis.

Burning mouth syndrome is a chronic condition, which is characterised by a burning sensation or pain in the mucosa of the oral cavity. Treatment options include antidepressants, antipsychotics, anticonvulsants, analgesics, hormone replacement therapies and more recently photobiomodulation. This study aims to perform a systematic review with meta-analysis in order to determine the effect of photobiomodulation on pain relief and the oral health-related quality of life associated with this condition. A bibliographical search of the Pubmed, Embase, Web of Science and Scopus databases was conducted. Only randomised clinical trials were included. Pain and quality of life were calculated as mean difference and pooled at different treatment points (baseline = T0 and final time point = Tf) and laser modality. From a total of 103 records, 7 articles were retrieved for inclusion. PBM group had a greater decrease in pain than control group at Tf with a mean difference = - 2.536 (IC 95% - 3.662 to - 1.410; I2 = 85.33%, p < 0.001). An improvement in oral health-related quality of life was observed in both groups, although this was more significant in the photobiomodulation group mean difference = - 5.148 (IC 95% - 8.576 to - 1.719; I2 = 84.91%, p = 0.003). For the red laser, a greater improvement than infrared was observed, in pain, mean difference = - 2.498 (IC 95% - 3.942 to - 1.053; I2 = 79.93%, p < 0.001), and in quality of life, mean difference = - 8.144 (IC 95% - 12.082 to - 4.206; I2 = 64.22%, p = 0.027). Photobiomodulation, in particular, red laser protocols, resulted in improvement in pain and in quality of life of burning mouth syndrome patients.

DNA Methylation by Bisulfite Next-Generation Sequencing for MLH1 and MGMT in Oral Squamous Cell Carcinomas and Potentially Malignant Disorders: An Integrative Analysis towards Field Cancerization.

Background and Objectives: MGMT methylation is a well-described biomarker in several solid tumors and MLH1 seems to occur in the initial stages of oral carcinogenesis. The aims of this study were to evaluate MHL1 and MGMT methylation levels in oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMDs), and to integrate this information with The Cancer Genome Atlas (TCGA) database. Materials and Methods: To determine the percentage of gene methylation in MLH1 and MGMT, pyrosequencing analysis was conducted. Samples were divided as follows: (1) patients diagnosed with OSCC (N = 16); (2) patients with OPDM who developed OSCC in the same location (N = 47); and (3) patients with OPDM who developed OSCC in a different location (N = 22). As a validation cohort in this study, data from The Cancer Genomic Atlas (TCGA) database, particularly regarding Head and Neck Squamous Cell Carcinoma, was used. Results: Overall MLH1 methylation levels of 8.6 ± 11.5% and 8.1 ± 9.2% for MGMT were obtained. With regard to MHL1, the OSCC presented the highest degree of methylation with 9.3 ± 7.3% (95%CI 5.1-13.6), and with regards to MGMT, the simultaneous malignancy group presented the highest degree of methylation with 10 ± 13.5% (95%CI 6-10), although no significant differences were found between the groups (p = 0.934 and p = 0.515, respectively). The estimated survival was higher for MGMT methylated cases (19.1 months, 95%CI 19.1-19.1) than for unmethylated cases (9.4 months, 95%CI 6-12.8), but not statistically significant. Conclusions: Our results did not show a correlation between MGMT and MLH1 methylation and any clinicopathological feature or survival in our institutional cohort. MLH1 methylation was present mainly in OSCC, whilst MGMT in OPMD represented a modest contribution to field cancerization, with an overall consistency with the TCGA database.

Metabolic syndrome and masticatory hypofunction: a cross-sectional study.

The objective of this paper is to clarify the rate of abdominal obesity (AO), waist-to-height ratio (WHtR), metabolic syndrome (MetS) and determine the relationship with the masticatory capacity (MC) in terms of total functional tooth units (t-FTU) in a representative sample of older Spanish adults. This cross-sectional study included 544 adult subjects aged 50 or over, who were prospectively selected and who had participated in a survey conducted in a primary dental care service in a Public Oral Health Service in Spain. Anthropometric, clinical variables and t-FTUs were obtained through a calibrated and well-established protocol. Univariate and multivariate binary and multinomial logistic regression analyses were developed. With regards to the t-FTU or MC, it was poor in 60.3%, good in 17.6%, and complete in 22.1% of the sample. The univariate odss ratio (OR) for MetS and AO increased as the MC decreased and as the age group increased. With regards to gender, women presented with an OR of 5.56 (CI 95% 3.70-8.38). With regards to the WHtR-a3 (WHtR grouped into three categories), the univariate ORs were all significant for morbid obesity compared to the healthy group, with a risk of 6.86 (CI 95% 3.23-14.58) for patients with poor MC compared to those with complete MC. Masticatory hypofunctionality could be associated with the presence of MetS. Clinical relevance: The number of t-FTUs is directly related to AO.

Validity, reliability and optimisation of the TOPICOP questionnaire for oral lichen planus.

Objectives: Due to their anti-inflammatory and immunosuppressive effects, topical corticosteroids (TCs) are commonly used for the treatment of patients with oral lichen planus (OLP) with an erosive or ulcerative component. It has been suggested that many of these patients may suffer from fear or anxiety as a result of prolonged treatment with TCs. The objective of this study was twofold: (1) to optimise a patient reported outcome measure (PROM) in order to explore this feature, and (2) to evaluate this PROM in the treatment of OLP patients.Methods: A group of qualitative researchers adapted the TOPICOP questionnaire in order for it to be used as a PROM for OLP via structural equation modelling (SEM) and internal consistency (IC) analysis. Consequently, 34 patients with symptomatic OLP who were undergoing treatment with TCs completed a questionnaire and underwent a clinical assessment.Results: SEM presented an adequate fit (RMSA = 0.07, CFI = 0.94 and WRMR = 1.18), as well as a high IC (α = 0.81). A total of 16 patients (47.1%) reported TCs phobia. The receiver operating characteristic analysis (ROC) revealed that a TOPICOP value ≥50% predicted the presence of TCs phobia with a sensitivity of 93% and a specificity of 100%.Conclusions: The optimised TOPICOP scale proved valuable as a PROM in OLP. TCs phobia can be a real consideration in OLP, nonetheless, it does not appear to be an impediment to treatment adherence.

Multicentre retrospective study of 97 cases of intraoral lipoma.

BACKGROUND: Lipomas are benign neoplasms derived from adipose tissue that are unfrequently found in the oral cavity. The objective of this study is to identify the main clinicopathological characteristics of this tumour in a case series of oral lipomas (OL) in a population from Spain and Brazil. MATERIAL AND METHODS: A multicentre retrospective observational study was conducted in collaboration with the Oral Pathology Unit of the São Paulo State University (UNESP), São José dos Campos, in Brazil, and the Oral Medicine and Pathology Units of the University of Santiago de Compostela (USC) and the University of the Basque Country (UPV/EHU) in Spain. RESULTS: This multicentre series consists of a total of 97 of OL cases, 31 (32%) of which correspond to Spain, and 66 (68%) to Brazil with an overall prevalence of 0.33%. The average age of the patients is 56.44 years old, with a range of 10-92 (SD = 15.52). Buccal mucosa was the most frequent location (42.3%). Cases from Spain coexisted with other lesions in a significant number of cases, 12.9%, vs Brazil, 1.5% (P = 0.018). According to the progression time, Brazil has an average of 60.35 months (CI: 27.20-93.51), compared to 5.41 months in Spain (CI: 3.17-7.65) (P = 0.022). Average size is 12.55 mm (SD = 11.06), ranging from 2 to 75 mm. A positive correlation is also seen between the increase in the lesion size and a greater progression time (CC = 0.367; P = 0.008). CONCLUSIONS: Correct differential diagnosis of the clinical lesion is key, followed by a good histopathological study, to achieve the final diagnosis.

Lichen planus and diabetes mellitus: Systematic review and meta-analysis.

OBJECTIVE: The aim of this study was to perform a systematic review and meta-analysis answering the following questions: (a) "What is the prevalence and risk of oral lichen planus among patients with diabetes mellitus?" and (b) "What is the prevalence and risk of diabetes mellitus among patients with oral lichen planus?". MATERIAL AND METHODS: A bibliographic search was conducted in PubMed/Medline and Scopus database from 1966 to March 2018, using the following terms: "Lichen planus" AND "Diabetes mellitus" AND "Prevalence" AND "Oral mucosal lesions". RESULTS: Twenty-two studies were included in this review. Twelve studies assessed the prevalence of diabetes mellitus among patients with lichen planus. The prevalence reported ranges from 1.6% to 37.7% with a relative risk of 2.432. Ten studies assessed the prevalence of lichen planus among patients with diabetes mellitus which showed a prevalence of lichen planus ranging from 0.5% to 6.1% with a relative risk of 1.4. CONCLUSIONS: Contradictory results were found when analyzing the relationship between lichen planus and diabetes mellitus. Diverse factors should be considered when studying this association for a correct interpretation of results. Diabetes mellitus has high prevalence and morbidity, which is why new case-control studies are needed to further investigate this association.

Psychological disorders and quality of life in oral lichen planus patients and a control group.

OBJECTIVES: Oral lichen planus (OLP) is a common disease whose aetiopathogenesis is linked to psychological disorders. This study aims to determine the influence of anxiety and depression in OLP patients, define the perception of quality of life in these patients and check for potential differences between atrophic/ ulcerative and reticular lesions. MATERIALS AND METHODS: A group of 48 OLP patients and a control group of 40 patients were selected. In order to assess anxiety, depression and quality of life, Hospital Anxiety and Depression Scale (HADS) and Oral Health Impact Profile 14 (OHIP-14) tests were completed. RESULTS: OLP patients showed higher scores on HADS (anxiety p < 0.01, depression p < 0.05) and OHIP-14 (physical pain p < 0.05, psychological discomfort p = 0.001). Patients with reticular lesions obtained higher scores in HADS (anxiety p = 0.001, depression p < 0.001), whereas patients with atrophic/ ulcerative lesions obtained higher scores in OHIP-14 (p = 0.02). CONCLUSIONS: Psychological disorders play an important role as a trigger for OLP and are responsible for many relapses. Psychological support would be advisable in order to improve their mental health, as this would have a positive impact on their quality of life and would lead to a better progression of the disease.

Exosomes in head and neck cancer. Updating and revisiting.

Exosomes have gone from being considered simple containers of intracellular waste substances to be considered important carriers of cellular signals. Its broad capacity to promote tumour growth, both in situ and metastatic, has greatly intensified scientific research on them. In the same way and depending on its content, its tumour suppressive properties have opened a window of light and hope in the fight against cancer. In the present review we try to gather in a simple and understandable way the most relevant knowledge to date on the role of exosomes in oral squamous cell carcinoma, helping to understand their process of formation, release and activity on the tumour microenvironment.

Knowledge About the Relation Between Tobacco and Disease and the Attitude Toward Advising the Cessation of Its Consumption Among a Group of Spanish Dental Students.

Tobacco is one of the leading causes of preventable death in the developed world. Smoking is associated with a large number of oral pathologies, such as cancer and periodontitis. Dental professionals can play a key role in preventing these health problems. The objectives of this study were (1) to analyze tobacco consumption habits among a group of Spanish dental students, and (2) to assess their knowledge, perceptions, and attitudes regarding procedures to help patients quit smoking. A cross-sectional descriptive study was carried out at the Faculty of Medicine and Dentistry of Santiago de Compostela (Galicia, Spain). Three validated questionnaires were distributed, and the obtained data was processed using SPSS. One hundred twenty out of 220 surveys were completed. Of the students, 18.3% were smokers and the average number of smoked cigarettes per day was 7.5. Tobacco dependence and the intention to give up the habit were low (Fagerström Test) and doubtful (Richmond test), respectively. The majority of students (94.2%) considered it appropriate to promote tobacco use cessation (TUC) activities. A great divergence of criteria regarding tobacco-associated pathologies was found among courses. This article provides positive data about the motivation of dental students to implement TUC strategies. Nevertheless, the usefulness of these interventions makes it necessary to modify the university curricula in order to improve the education on this issue to reduce the incidence of future health problems.