Patient perception after oral biopsies: an observational outpatient study.

OBJECTIVE: The aim of this study was to evaluate the postoperative course in patients undergoing oral mucosal biopsies, considering clinical and patient's perception variables potentially correlated to poor healing. SUBJECTS AND METHODS: Eighty patients underwent oral biopsies. All the variables connected with the surgery were recorded, and the harvested volume was calculated through image software (ImageJ, NIH, Betesda, USA). To evaluate the postoperative discomfort, the OHIP-14 and the numeric rating scale of pain (NRS) were administered at 6 h, 7 days and 21 days after biopsy. RESULTS: Six hours after the biopsy, 22 (OHIP-14 ≥ 20) and 24 (NRS ≥ 4) patients experienced a troublesome or painful healing, respectively. A significant statistical correlation between poor healing and high scores of NRS and OHIP was detected (Pearson's correlation test p < 0.05). Higher values of OHIP-14 were correlated to the type of lesion (OR = 1.165; p < 0.05), whereas high values of NRS were correlated to the use of systemic drugs (p < 0.05). No surgical variable had a significant statistical correlation with any of the outcomes. CONCLUSIONS: The clinical evaluation was correlated with the patient's perception of pain and discomfort. This finding could be suggestive of the fact that wound healing can be reliably monitored with the help of these tools. CLINICAL RELEVANCE: Patient perception can be a predictor of the healing of biopsied tissues.

Temporomandibular disc displacement with reduction treated with anterior repositioning splint: a 2-year clinical and magnetic resonance imaging (MRI) follow-up.

Clicking may appear in the initial, middle, or final phase of mandibular opening. Magnetic Resonance Imaging (MRI) is the most appropriate diagnostic imaging for diagnosing disc position. With anterior repositioning splint (ARS), disc recapture is achieved through a change in the position of the condyle to encourage adaptation of the retrodiscal tissues. Three patients reported pain and sounds during movement and clicking in the final phases; also, the MRI confirmed anteriorized disc position and the treatments consisted of an ARS. The post-treatment examination confirmed a normal opening without deviations and deflections. After 2 years, the conditions were stable, and the MRI showed thickening of the retrodiscal tissues, including extra fibrous tissue, resulting in a pseudodisc. Treatment using ARS can stimulate tissue fibrosis and the formation of a pseudodisc. MRI is the gold standard for diagnosis and treatment planning of disc displacement cases.

Analysis of lip pigmentations by reflectance confocal microscopy: report of two cases.

Oral mucosa pigmentations belong to a heterogeneous variety of lesions, which are usually divided into two groups: exogenous or endogenous pigmentations. The pigmented lesions most frequently found in the oral mucosa are the amalgam tattoo, the melanotic macula and the nevus. All these lesions may affect every part of the oral mucosa, and they may represent a hard diagnostic challenge for the clinician; the clinical objective examination is not sufficient to make a correct diagnosis. Reflectance Confocal Microscopy provides a real-time microscopic evaluation of tissue layers, and is widely considered a useful auxiliary tool in monitoring skin and mucosa lesions. In this context, Reflectance Confocal Microscopy imaging is a valid aid in the management of oral mucosa pigmented lesions, to corroborate and support the diagnostic process.

Analysis of oral mucosa erosive-ulcerative lesions by reflectance confocal microscopy.

In vivo Reflectance Confocal Microscopy (RCM) allows to optically biopsy vital tissues, non-invasively and in real time. It results in horizontal virtual slices at a microscopic resolution and correlating with conventional histopathology. The aim of the present work is to describe RCM cellular and architectural findings in oral mucosae affected by erosive-ulcerative diseases, thus highlighting in vivo the wellknown histological peculiarities. A series of conventionally diagnosed Recurrent Aphthous stomatitis (RAS) and Pemphigus Vulgaris (PV) erosive and/or ulcerative oral lesions underwent RCM imaging to establish the application of RCM imaging to this kind of inflammatory non-tumoral lesions. A total of 12 RAS-related lesions and 8 PV-related lesions were considered. RCM imaging was capable to visualize their microscopic peculiarities, mainly inflammatory infiltrate, vessel dilation (RAS) and acantholytic cells, intraepithelial clefts and inflammatory cell carpets (PV). Despite RCM may result unnecessary to diagnose oral lesions referred to RAS and PV, its capability to highlight their main microscopic features could be advantageously used to monitor the healing or worsening of the clinical situation as well as the responsiveness/refractoriness to therapy.

Association between denture stomatitis, candida species and diabetic status.

Candida species are commensal yeasts of the oral cavity, which, under predisposing systemic and/or local circumstances, are responsible for a wide variety of clinical manifestations, globally known as oral candidiasis. Candida-associated denture stomatitis is an oral candidiasis particularly affecting the oral mucosa covered by a dental prosthesis, with several degree of severity. Diabetics suffer oral candidiasis more frequently than healthy individuals do and if they are denture wearers, the risk increases. Since various controversies still remain regarding the interrelationship among diabetes, oral Candida spp. strains involved in denture stomatitis and the presence of dentures, the present review aims to investigate the differences in Candida species frequencies and degree of denture stomatitis severity existing among diabetic and non- diabetic individuals, with and without dentures.

Topical toluidine blue-mediated photodynamic therapy for the treatment of oral lichen planus.

Photodynamic Therapy (PDT) is a minimally invasive approach that has shown promising results in management of oral, head and neck lesions. PDT can be used alone or in combination with other conventional treatments (surgery, chemotherapy, radiotherapy). Oral Lichen Planus (OLP) is a mucosal and cutaneous chronic disease characterized by an autoimmune insult of basal keratinocytes. We aim to evaluate the feasibility of topical toluidine blue-mediated PDT for the treatment of oral cavity multifocal homogeneous white lesions by oral lichen planus without dysplastic features.

Radiosurgery-assisted gingival displacement: a proof of concept technique to enhance the efficiency of intraoral digital impression.

Nowadays, an increasing number of dentists are using intraoral scanners (IOS) in their daily practice as an alternative to conventional impression taking. One of the main concerns is related to the capability of scanning the subgingival anatomy of the die, usually very challenging due to the limited operative field and the presence of oral fluids. The radiosurgery assisted gingival displacement technique (RAGD) may enhance the intraoral optical scanning of the finish line and neighbor tooth anatomy. The contour of the interim prosthesis is used to drive the tip of radiosurgery electrode along the tooth surface and open selectively the gingival crevice with a prosthetically-driven and minimally invasive approach. The clinical implication of this technique is related to increasing the efficiency and accuracy of the digital impression technique in the critical zone of the prosthetic shoulder.

Colonization of Legionella spp. In dental unit waterlines.

Legionella spp. are ubiquitous in aquatic habitats and water distribution systems, including dental unit waterlines. Surveys have shown that the percentage of samples taken at different dental sites that were positive for Legionella spp. were highly variable and ranged from 0% to 100%. Cultivation is the principal approach to evaluating bacterial contamination employed in the past, but applying this approach to testing for Legionella spp. may result in false-negative data or underestimated bacterial counts. PCR and direct fluorescent counts can detect viable non-cultivable bacteria, which are not counted by plating procedures. Legionella spp., commonly form such viable non-culturable cells and it is likely that they contribute to the difference between plate count results and those of PCR and fluorescent-antibody detection. However, studies have shown that Legionella is present in the municipal water source in spite of the current filtration and chlorination procedures. Once Legionella reaches the building water system, it settles down into a biofilm layer of stagnant water. By means of this layer, Legionella can protect itself from antimicrobial agents and then multiply. Dental unit waterlines may be contaminated with opportunistic bacteria. The water quality in the dental units should be controlled to eliminate opportunistic pathogens and to provide water for dental treatment that meets public health standards for potable water.

Focus on periodontal disease and development of endocarditis.

Infective endocarditis is a devastating disease with high morbidity and mortality. The link to oral bacteria has been known for many decades and has caused ongoing concern for dentists, patients and cardiologists. The microbiota of the mouth is extremely diverse and more than 700 bacterial species have been detected. Half of them are uncultivable so far. Oral microbiota is not uniform, specific sites exist in the mouth such as tongue, palate, cheek, teeth and periodontal pockets that have their own microbiota. Factors involved in the development of a bacterial endocarditis are difficult to define but a vulnerable surface (i.e. a damaged endocardium) and a high bacterial load in the blood seems to be decisive. The cause of microorganisms, in 90% of cases, are staphylococcus, streptococcus and enterococcus. Oral streptococci belong to viridans group (streptococcus mutans and streptococcus sanguis). As they are part of dental plaque, they could enter the bloodstream causing bacteraemia through daily habits like chewing or tooth brushing. Effective treatment of periodontal infections is important to reduce local inflammation and bacteraemia. In addition, poor periodontal health appears to increase the risk of cardiovascular disease, pulmonary disease, and preterm and low birth weight. CONCLUSIONS: Long-standing oral disease prevention protocols reduce the risk of developing periodontal disease. Data suggests that methods used to prevent cases of IE that originate from oral bacteria should focus on improving oral hygiene and reducing or eliminating gingivitis, which should reduce the incidence of bacteraemia after tooth-brushing and the need to extract teeth owing to periodontal disease and caries.

Evaluation of the intraepithelial papillary capillary loops in benign and malignant oral lesions by in vivo Virtual Chromoendoscopic Magnification: a preliminary study.

This preliminary study aims to establish the Virtual Chromoendoscopic Magnification (VCM) feasibility to visualize and distinguish the Intraepithelial Papillary Capillary Loops (IPCL) patterns of benign oral pathologies from malignant ones. Thirty-one consecutive subjects affected by oral lesions/pathologies underwent white light examination and VCM imaging by the Narrow Band Imaging System (Olympus Medical Systems Corp., Tokyo, Japan). A class system of four IPCL types corresponding to progressive vessel disarray was adopted. IPCL type IV were considered criterion of “malignancy”. A histopathological exam completed the diagnosis: sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated. IPCL patterns of benign oral entities ranged from types I to III. IPCL type IV was associated with malignancy in 4 out of 6 cases. Sensitivity, specificity, PPV, and NPV were 100%, 93%, 67% and 100%, respectively. This study preliminarily describes IPCL patterns of different oral mucosal diseases and confirms the association between IPCL IV and oral cancer.

Oral squamous cell carcinoma: diagnostic markers and prognostic indicators.

OSCC is the most frequent malignant tumour of the oral cavity, accounting for more than 90% of malignant tumours of this anatomic region and it often arises from precursor lesions. Aside from tobacco and alcohol consumption, further determinants have been considered to increase the risk of OSCC development, such as micronutrient deficiencies, chronic traumatism, poor oral hygiene and viruses. Recurrence, survival and conversely, mortality depends on numerous and different biological, histological, macroscopic and microscopic factors that have been investigated in order to define causes, to help diagnosis and to refine appropriate treatments that perfectly fit with the different features of OSCCs. For this purpose, during the last decades, the improvement of scientific technologies and molecular analyses have allowed to investigate markers and genetic and epigenetic factors, in order to clarify their responsibilities related to early diagnosis and OSCC progression and prognosis in order to address them as targets in future selective and individually-shaped therapies. This review will focus on the etiology, advances in diagnostic markers and prognostic indicators for oral cancers.

Assessment of host defence mechanisms induced by Candida species.

Some species of Candida are opportunistic pathogens that can cause disease in a host immunocompromised by underlying local or systemic pathological processes. C. albicans is the species most often associated with oral lesions, but other species of Candida, including C. glabrata, C. tropicalis and C. parapsilosis, have also been isolated in the saliva of subjects with and without candidiasis. In the present study we evaluated the host defence mechanisms induced by Candida albicans and other Candida species in monocytes and oral epithelial cells in order to establish the existence of a species-specific cellular response. Our results indicated that, during Candida species infection, the epithelial cells actively participate in the host defence by producing antimicrobial peptides and proinflammatory cytokines. Moreover, in infections caused by Candida tropicalis and Candida glabrata, the host defence may be strengthened by the release of perforin and granzyme by polymorphonuclear leukocytes recruited at the site of infection.

Pilot study on reflectance confocal microscopy imaging of lichen planus: a real-time, non-invasive aid for clinical diagnosis.

BACKGROUND: Lichen planus (LP) represents a relatively common skin inflammatory entity included in the major group of interface dermatitis. In recent years, reflectance confocal microscopy has demonstrated to be a valuable tool for the 'in vivo' characterization of various skin diseases with cellular level resolution. No data are currently available that uses reflectance confocal microscopy to study LP. OBSERVATIONS: In this study, we have investigated the clinical and confocal features of five cases of histopathologically proven LP, and we have correlated the observed features with histopathological findings. The most characteristic criterion was the presence of interface dermatitis. Papillary rims, usually visible in normal skin, were obscured by the presence of a diffuse inflammatory cells infiltrate, arranged in sheet-like structures that surrounded the junction almost completely. There was an almost total obliteration of the ring-like structures around DP, which appeared non-edged and non-rimmed. Granular cells appeared as very large, polygonal structures, with an evident grainy cytoplasm, with the transition between spinous and granular cells being clearly recognizable, and this feature corresponded to hypergranulosis in histology. The presence of inflammatory cells at the level of the epidermis was seen as round-to-polygonal bright structures in the context of a variable degree of epidermal disarray and spongiosis. Melanophages in dermis were visible as brightly refractile, plump, oval to stellate-shaped cells. Prominent round or linear dark canalicular structures corresponded to dilated blood vessels in the superficial dermis on histopathology and appeared horizontally oriented in confocal sections. CONCLUSIONS: Reflectance confocal microscopy may represent a real-time, non-invasive aid to clinical diagnosis of LP. However, it might be difficult to distinguish between different subtypes of interface dermatitis. Further research, including larger case series, will better define a possible differential diagnosis of these diseases using confocal microscopy.

Lymphovascular invasion as a prognostic tool for oral squamous cell carcinoma: a comprehensive review.

Oral cancer is the most common malignancy of the head and neck region, characterized by a poor prognosis. Novel prognostic markers are needed to better stratify these patients. Lymphovascular invasion (LVI) has been included in the eighth edition of the AJCC Cancer Staging Manual as an additional prognostic factor, but its influence on the recurrence risk and lymph node metastasis is relatively understudied. This is a comprehensive review of the literature on the clinical and prognostic role of LVI in oral cancer. A relevant search of the PubMed, Scopus, and Web of Science databases yielded 29 articles that satisfied the inclusion criteria. Findings indicated that LVI is an independent negative prognostic factor in oral cancer patients and appears to be associated with cervical lymph node metastasis and loco-regional recurrence. Notably, in oral tongue cancer, survival outcomes progressively worsen when LVI is associated with other adverse pathological features, especially in the early stages. Therefore, these patients could benefit from elective neck dissection and/or adjuvant therapy. The high variability of LVI prevalence hinders the comparison of literature results. Several methodological limitations were found to be present in the collected articles, including the lack of a rigorous definition for LVI, the difficult detection in routine histological section, the presence of potential confounders, the retrospective nature, and an inadequate sample size in most studies. Therefore, it is necessary to conduct prognostic studies using standardized methods to define and quantify LVI.

Double demonstration of oncogenic high risk human papilloma virus DNA and HPV-E7 protein in oral cancers.

Oncogenic HPVs are necessarily involved in cervical cancer but their role in oral carcinogenesis is debated. To detect HPV in oral cancer, 38 cases of formalin fixed-paraffin embedded OSCC were studied by both DNA genotyping (MY09/11 L1 consensus primers in combination with GP5-GP6 primer pair followed by sequencing) and immunohistochemistry (monoclonal Abs against capsid protein and HPV-E7 protein, K1H8 DAKO and clone 8C9 INVITROGEN, respectively). HPV-16 tonsil cancer was used as positive control. The overall prevalence of HPV infection in OSCCs was 10.5%. Amplification of DNA samples showed single HPV DNA infection in 3 cases (HPV16; HPV53; HPV70) and double infection in one case of cheek cancer (HPV31/HPV44). The overall HR-HPV prevalence was 7.5%. E-7 antigen was immunohistochemically detected in all HPV-positive cases. HPV+ OSCC cases showed an overall better outcome than HPV negative oral cancers, as evaluated by Kaplan-Meier curves. HPVs exert their oncogenic role after DNA integration, gene expression of E5, E6 and E7 loci and p53/pRb host proteins suppression. This study showed that HPV-E7 protein inactivating pRb is expressed in oral cancer cells infected by oncogenic HPV other than classical HR-HPV-16/18. Interestingly HPV-70, considered a low risk virus with no definite collocation in oncogenic type category, gives rise to the expression of HPV-E7 protein and inactivate pRb in oral cancer. HPV-70, as proved in current literature, is able to inactivates also p53 protein, promoting cell immortalization. HPV-53, classified as a possible high risk virus, expresses E7 protein in OSCC, contributing to oral carcinogenesis. We have identified among OSCCs, a subgroup characterized by HPV infection (10.5%). Finally, we have proved the oncogenic potential of some HPV virus types, not well known in literature.

Inhibition of HSV-1 replication by laser diode-irradiation: possible mechanism of action.

Herpes labialis are the most frequent clinical manifestations of HSV-1 infection. Epithelial cells are able to respond to HSV-1 presence inducing the expression of IL-6, IL-1, TNF-α and IL-8. These proinflammatory cytokines have a function in the acute-phase response mediation, chemotaxis, inflammatory cell activation and antigen-presenting cells. In the human epithelial cell models, it has been demonstrated that, after an early induction of proinflammatory host response, HSV-1 down-modulates the proinflammatory cytokine production through the accumulation of two viral proteins, ICP4 and ICP27, whose transcription is induced by tegument protein VP16. These viral proteins, through the decreasing of stabilizing the mRNAs of proinflammatory genes, delay cytokine production to an extent that allows the virus to replicate. Moreover, viral transactivating proteins, ICP-0 and VP-16 induce IL-10 expression. The conventional treatment of herpes labialis involves the topical and systemic use of antiviral drugs but it is necessary to find new therapies that can act in a selective and non-cytotoxic manner in viral infection. Laser diode therapy has been considered as a non-invasive alternative treatment to the conventional treatment of herpes labialis in pain therapy, in modulation of inflammation and in wound healing. This study aims to report a possible mechanism of action of laser diode irradiation in prevention and reduction of severity of labial manifestations of herpes labialis virus. We investigated, in an in vitro model of epithelial cells HaCat, the laser-effect on HSV-1 replication and we evaluated the modulation of expression of certain proinflammatory cytokines (TNF-α, IL-1ß and IL-6), antimicrobial peptide HBD2, chemokine IL-8 and the immunosuppressive cytokine, IL-10. Our results lead us to hypothesize that LD-irradiation acts in the final stage of HSV-1 replication by limiting viral spread from cell to cell and that laser therapy acts also on the host immune response unblocking the suppression of proinflammatory mediators induced by accumulation of progeny virus in infected epithelial cells.

Bisphosphonate-related osteonecrosis of the jaws and dental surgery procedures in children and young people with osteogenesis imperfecta: A systematic review.

BACKGROUND: Bisphosphonates (BPs) contrast the bone fragility and improve bone density in some metastatic cancers and bone diseases, such as Osteogenesis Imperfecta (OI). BPs use has been associated with osteonecrosis of the jaws (BRONJs) in adults needing for invasive dental procedures. AIM: To conduct a systematic review on BRONJ occurrence after dental surgery in paediatric population under BPs therapy for OI, so as to identify the pre-surgical protocols adopted. DESIGN: According to PRISMA guidelines, Pubmed, Web of Science (WoS) and Cochrane were investigated on September 2018, and re-checked on July 2019. Inclusion criteria were English-language papers on children/young adults (until 24 years old) reporting dental/oral surgery procedures. RESULTS: Totally, 60 articles were found. After title/abstract reviews and duplicates exclusion, 22 eligible titles underwent full-text evaluation. Finally, 10 studies were included. CONCLUSIONS: The lack of BRONJ occurrence in paediatric population suffering OI and treated with BPs, was confirmed, but the reasons are still debated, being the BPs therapies and the surgical strategies various and not standardized. Longitudinal studies should evaluate what happens to those former children once adult, to evaluate the delayed BRONJs onset associated with the occurrence of comorbidities during the adulthood.

A comparative study on different stemness gene expression between dental pulp stem cells vs. dental bud stem cells.

OBJECTIVE: The clinical use of mesenchymal stem cells (MSCs) in regenerative medicine either in tissue repair or tissue reconstruction has given highly interesting results thanks to their particular nature. Sources that have attracted the attention of medical scientists from where stem cells (SCs) in adults could be obtained are different and, dental tissues have certainly become an optimal source of MSCs. Dental tissue is a main reservoir of two types of MSCs dental bud (DBSCs) that constitute the immature precursor of the tooth and dental pulp (DPSCs) that are derived from dental inner pulp and partly from dental follicle tissue and can differentiate into several cell phenotypes as osteoblast, chondrocyte, hepatocytes, cardiomyocytes, neuron and ß cells. PATIENTS AND METHODS: Normal impacted third molars and tooth buds were collected from adults and adolescents underwent to extractions for orthodontic reasons. The expression of the five stemness genes Nanog, OCT4, Sox2, c-Myc and Klf4 were investigated by qRT-PCR in two different dental stem/progenitor cells: dental pulp stem cells (DPSCs) and stem cells from dental bud (DBSCs), differentiated toward osteoblastic phenotype and not. RESULTS: Both DPSCs and DBSCs are easy to access and we found their expression of the typical mesenchymal stemness makers and osteogenic capacity due to the effective presence of embryonic gene regulators like Nanog, OCT4, Sox2, c-Myc and Klf4. Both DBSCs and DPSCs could represent a valid tool in regenerative medicine and translational applications. CONCLUSIONS: The results depicted here provide, for the first time to our knowledge, a comparative outcome about the stemness properties generated from accessible tissues such as DPSCs and DBSCs. These two types of SCs showed few different distinctive genetic traits supposedly in relation to their origin, location and stage of maturation. Certainly these SCs reserve solid potential for human clinical application in autologous procedure for bone, hard tissue and soft tissue regeneration, easy to isolate, ready availability, high-biocompatibility and safety and no ethical restrictions.

Stemness genes expression in naïve vs. osteodifferentiated human dental-derived stem cells.

OBJECTIVE: Mesenchymal stem cells (MSCs) have been deeply investigated in regenerative medicine because of their crucial role in tissue healing, such as tissue regeneration. Dental-derived stem cells (d-DSCs) are easily available from dental tissues, which can be isolated from all age patients with minimal discomfort. PATIENTS AND METHODS: Normal unerupted third molars tooth buds were collected from adolescents' patients underwent to extractions for orthodontic reasons. The expression of the genes Kruppel-like factor 4 (Klf-4), octamer-binding transcription factor 4 (Oct-4), homeobox transcription factor Nanog (NANOG) was investigated in d-DSCs obtained from dental bud (DBSCs), differentiated toward osteoblastic phenotype and not. RESULTS: Our results showed that DBSCs expressed Oct-4, Nanog, and Klf-4 in undifferentiated conditions and interestingly the expression of such genes increased when the cells were kept in osteogenic medium. CONCLUSIONS: These attractive stemness properties, together with the effortlessly isolation, during common oral and maxillofacial surgical procedures, from undifferentiated tissues such as dental bud, make this kind of d-DSCs a promising tool in regenerative medicine, having the potential for clinical applications, and reinforcing the present challenge to develop new preventive and healing strategies in tissue regeneration.

The role of E-cadherin down-regulation in oral cancer: CDH1 gene expression and epigenetic blockage.

BACKGROUND: The prognosis of the oral squamous cell carcinoma (OSCC) patients remains very poor, mainly due to their high propensity to invade and metastasize. E-cadherin reduced expression occurs in the primary step of oral tumour progression and gene methylation is a mode by which the expression of this protein is regulated in cancers. In this perspective, we investigated E-cadherin gene (CDH1) promoter methylation status in OSCC and its correlation with Ecadherin protein expression, clinicopathological characteristics and patient outcome. METHODS: Histologically proven OSCC and paired normal mucosa were analyzed for CDH1 promoter methylation status and E-cadherin protein expression by methylation-specific polymerase chain reaction and immunohistochemistry. Colocalization of E-cadherin with epidermal growth factor (EGF) receptor (EGFR) was evidenced by confocal microscopy and by immunoprecipitation analyses. RESULTS: This study indicated E-cadherin protein down-regulation in OSCC associated with protein delocalization from membrane to cytoplasm. Low E-cadherin expression correlated to aggressive, poorly differentiated, high grade carcinomas and low patient survival. Moreover, protein down-regulation appeared to be due to E-cadherin mRNA downregulation and CDH1 promoter hypermethylation. In an in vitro model of OSCC the treatment with EGF caused internalization and co-localization of E-cadherin with EGFR and the addition of demethylating agents increased E-cadherin expression. CONCLUSION: Low E-Cadherin expression is a negative prognostic factor of OSCC and is likely due to the hypermethylation of CDH1 promoter. The delocalization of E-cadherin from membrane to cytoplasm could be also due to the increased expression of EGFR in OSCC and the consequent increase of E-cadherin co-internalization with EGFR.