Modulation of blood redox status by the progression of induced apical periodontitis in rats.

This study aimed to investigate if apical periodontitis in different periods changes systemic levels of the antioxidant and pro-oxidant parameters in Wistar rats. Twenty-four rats were randomly allocated into healthy animals, apical periodontitis at 14 days (AP14) and apical periodontitis at 28 days (AP28). The first mandibular molars were accessed in the AP groups, and the pulp chamber was exposed to the oral environment, inducing the apical lesion. After 14 and 28 days, the animals were anesthetized, euthanized, and hemimandibles were collected for micro-computed tomography (micro-CT) analysis to measure lesion volume, bone volume (BV), percent of bone to total tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular space (Tb.Sp). A histological examination of the remaining bone was also performed. Finally, blood samples were collected for oxidative biochemistry analysis, investigating glutathione (GSH), Trolox equivalent antioxidant capacity (TEAC), and lipid peroxidation (TBARS). The lesion volume was greater at 28 than at 14 days, as shown by micro-CT. AP14 and AP28 had decreased BV and Tb.Th, but only AP28 showed a reduction in BV/TV. Tb.N and Tb. Sp were increased in apical periodontitis at 28 days. In the histopathological analysis, AP14 had focal regions of moderate mononuclear inflammatory infiltrate, and AP28 had an intense inflammatory infiltrate with bacterial colonies. In the biochemical evaluation, GSH, TEAC, and TBARS were increased after 14 days. However, GSH returned to control levels, TEAC was similar to AP14, and TBARS increased significantly after 28 days. Therefore, the oxidative biochemistry response was modulated according to the progression of periapical damage. After 14 days, the organism could still react to the injury. However, at 28 days, the antioxidant response decreased, associated with an increase in TBARS.

Do dental implant therapies arouse signs and symptoms of temporomandibular disorders? A scoping review.

OBJECTIVE: To delineate and discuss the literature about TMD in the context of dental implantology. METHODS: The PRISMA-ScR and Joanna Briggs guidelines for scoping reviews were used as methodological parameters. In vivo studies published in the English language showing interplay between dental implant therapy and TMD were included. A systematic screen strategy was applied in two platforms to obtain a broad range of relevant literature published in English. RESULTS: The literature review indicated that prolonged surgical procedure may be a risk for TMD. Conversely, implant-supported prostheses were found to contribute to the mitigation of some TMD aspects. Empirical principles for the best practice in implant dentistry concerning the TMD were discussed in the present study. CONCLUSION: The included clinical studies suggest that factors associated with the implant placement, such as long duration of surgical procedures, may represent risk factors for TMD. They also indicate long-term benefits of implant-supported restorations.

Ocorrência simultânea de cisto dentígero e odontoma composto-complexo causando impacção dentária / Simultaneous occurrence of dentigerous cyst and compound-complex odontoma causing dental impaction

O presente trabalho ilustra e discute essa doença que representa o tumor odontogênico mais comum da prática clínica, o Odontoma. Para tal, apresenta um caso clínico com imagens clínicas e radiográficas esclarecedoras dos aspectos dessa doença, bem como discussão a partir de revisão narrativa de literatura direcionada para a carac-terização da doença. Relata-se o caso de um odontoma composto-complexo, uma forma incomum de odontoma, mas que mantém os demais aspectos usuais, sendo uma mulher de 21 anos com lesão radiopaca em maxila de-tectada devido à não erupção do 23. A remoção cirúrgica seguiu a partir de acesso anterior na maxila e o exame histopatológico mostrou os aspectos típicos de um Odontoma composto e complexo juntos. Independentemente da variante, nota-se que o Odontoma é quase sempre indolente, porém requer cuidados de remoção precoce devido à possibilidade de crescimento, de desenvolvimento de cistos e comprometimento de estruturas adjacentes devido a sua localização e possibilidade de crescimento (AU)

The present work illustrates and discusses this disease that represents the most common odontogenic tumor in clinical practice, the Odontoma. However, an unusual variation of the same is included here in the literature, char-acterized by the exams as a form of compound-complex odontoma additionally causing dentigerous cyst formation and dental impaction. The unusual case occurred in a 21-year-old woman, complaining of missing the tooth 23. The details of the exams allowed the visualization of compound and complex areas in the lesion, cystic formation and dental impaction. The histopathological findings confirmed the diagnosis of the Odontoma, and the interpreta-tion with the set of other exams led to the final diagnosis of Compound-complex odontoma with dentigerous cyst. The present case highlights the need for early removal of Odontoma due to the possibility of developing cysts, compromising adjacent structures, in addition to its growth potential already reported in the literature (AU)

Low-level laser or LED photobiomodulation on oral mucositis in pediatric patients under high doses of methotrexate: prospective, randomized, controlled trial.

PURPOSE: The objective of the present study was to compare the efficacy of photobiomodulation with low-level laser therapy (LLLT) or light-emitting diode therapy (LEDT) devices for the prevention and treatment of oral mucositis in pediatric patients diagnosed with acute lymphoblastic leukemia undergoing chemotherapy with high doses of methotrexate (MTX). METHODS: Eighty patients were randomly divided into two groups: LLLT and LEDT. Both protocols were applied with the same energy and radiant exposure. The protocols started in the beginning of high doses MTX and finished when the patients were discharged from the hospital or there was oral mucositis resolution. The oral mucositis was assessed during each session in accordance to the World Health Organization (WHO) score. The patients' self-assessed pain was scored on a visual analog scale (VAS). RESULTS: The incidence of oral mucositis was similar to LLLT and LEDT, 10% and 12.5%, respectively. Both groups required the same number of days to reach score of zero for mucositis and pain (p > 0. 05), and there was no significant difference in mean VAS between the groups. CONCLUSIONS: These findings suggest that LEDT has similar effects to LLLT to avoid and treat oral mucositis. Brazilian Clinical Trial Registry with #U1111-1221-5943.

Parasitological association between human leishmaniosis mucosa and paracoccidioidomycosis. Case report.

INTRODUCTION: Leishmaniasis Mucosa (LM) is a tropical disease that affects the upper respiratory tract and/or oral mucosa. Its etiological agent is Leishmania spp. Paracoccidioidomycosis disease caused by the fungus Paracoccidioides brazilienses. The aim is to report a case of Leishmaniasis Mucosa in association with Paracoccidioidomycosis. PRESENTATION OF CASE: A male patient, 24 years old; Intraorally, presence of a non-bleeding erythro-leucoplastic lesion that affected the soft palate and oropharynx; 3 years of evolution. On the face Computerized Tomography (CT) examination, it was possible to observe muco-periosteal thickening in the soft palate region; immunohistochemical markings for Paracoccidiodes brasiliensis. He was diagnosed with Leishmaniasis by Montenegro intradermoreaction (MIDR). DISCUSSION: The predisposition to Paracocodioidomycosis after Leishmaniasis infection is justified by factors already elucidated - hygiene, nutrition habits and immunodeficiency, but the reason for the non-progression of the fungus after years of evolution could be related to its inhibition due to the presence of the protozoan in the same wound. CONCLUSION: This phenomenon may be explained by future studies that need to be performed to answer such questions.

Oral mucosal lesions in patients with SARS-CoV-2 infection. Report of four cases. Are they a true sign of COVID-19 disease?

BACKGROUND: Vesiculobullous and macular lesions in the oral mucosa have been reported in patients positive for SARS-CoV-2 infection. Nonetheless, the significance and physiopathology of oral manifestations have not been clearly established in the clinical progression or outcome of the infection. AIM: To describe the clinico-pathological oral mucosal lesions in four patients with confirmed SARS-CoV-2 infection. METHODS AND RESULTS: Four patients with COVID-19 disease and confirmed by polymerase chain reaction (PCR) presented angina bullosa hemorragica-like lesion, vascular disorder, and nonspecific stomatitis, one patient with histological analysis demonstrated perivascular reactive lymphocitic infliltrate, focal capillary thrombosis, and hemorrhage. According to the discrimination of other local and systemic conditions and the synchronous onset of oral and systemic symptoms, the diagnosis of oral lesions probably associated with COVID-19 was established. CONCLUSION: Infection with SARS-CoV-2 may result in oral manifestations with various clinical presentations, which presumably support the hypothesis of thrombi formation and vasculitis; nevertheless, these findings need more evidence and a long-term follow up of patients to accurately establish the significance of the oral mucosa affection in the COVID-19 disease.

Effects of Dexamethasone and Photobiomodulation on Pain, Swelling, and Quality of Life After Buccal Fat Pad Removal: A Clinical Trial.

PURPOSE: In this study we aimed to compare the effects of photobiomodulation (PBM) and dexamethasone (DXM) on pain, swelling, and the quality-of-life (QOL) of patients submitted to buccal fat pad removal. PATIENTS AND METHODS: A total of 20 patients with pseudoherniation of buccal fat pad were included in the present study. The patients were divided randomly into 2 groups: the PBM group (660 nm, 100 mW, 6 seconds, 2 J/cm2) and the DXM group (4 mg every 8 hours for 3 days after the procedure). Pain levels were evaluated using a visual analog scale at days 2 and 4 after surgery, whereas the edema was evaluated by measuring the distance between 6 reference points: tragus, pogonion of the soft tissue, lateral eye commissure, the gonial angle, nose wing, and mouth commissure at days 2, 4, 7, 15, 30, 60, and 90. The QOL was evaluated using the Oral Health Impact Profile 14 questionnaire at days 2 and 4 after surgery. RESULTS: There were no differences between the PBM and DXM groups in pain or edema. In terms of the QOL, the PBM group was significantly more comfortable when chewing than the DXM group (P < .05) CONCLUSION: The use of PBM at a power of 100 mW and 2 J/cm2 per point had similar effects to oral DXM for the control of pain and edema, as well as in the QOL, except for masticatory function, which was significantly better in the PBM group.

Nonsteroidal Anti-inflammatory Drugs Modulate Gene Expression of Inflammatory Mediators in Oral Squamous Cell Carcinoma.

BACKGROUND: Most patients with head and neck cancer receive nonsteroidal anti-inflammatory drugs concomitant with oncogenic treatment in order to control cardiovascular diseases and chronic inflammatory processes. Inflammation is closely related to neoplastic development and the release of inflammatory cytokines and chemokines represents a crucial event in this relationship. The aim of the present study was to evaluate the effect of acetylsalicylic acid (ASA) and celecoxib treatment in the gene expression pattern of cytokines and chemokines in squamous cell carcinoma (OSCC) cell lines. MATERIALS AND METHODS: Cells were treated with plasmatic concentrations of ASA and celecoxib and were submitted to cell viability assay and immunoenzymatic assay to investigate interleukin 6 (IL6) production. Treated cells were collected and a gene expression array was performed using the reverse transcriptase-quantitative polymerase chain reaction. RESULTS: Both treatments provoked a discrete inhibitory effect on cell viability and modulated IL6 production. The mRNA expression of several cytokines, chemokines, chemokine receptors, and other chemotaxis-related genes were modulated after treatment with ASA and celecoxib. CONCLUSION: Plasmatic doses of ASA and celecoxib altered the expression of IL6 and the gene expression of chemokines (ligands and receptors) and cytokines in a dose- and time-dependent manner.

Photobiomodulation is associated with a decrease in cell viability and migration in oral squamous cell carcinoma.

The treatment of squamous cell carcinoma (SCC) involves surgery, chemotherapy, and/or radiotherapy, which can cause mucositis (inflammation of the oral mucosa that causes considerable pain and can compromise the continuity of oncological treatment). Photobiomodulation (PBM) has been successfully used in the treatment of mucositis, but doubts arise regarding the use of laser for areas in which tumor cells may remain. In this study, the effect of PBM on the viability, mitochondrial activity, proliferation, apoptosis, and migration of cells derived from oral SCC was evaluated. SCC9 cells were irradiated with laser (660 and 780 nm, using 11 dosimetric parameters) and submitted to mitochondrial and caspase 3 activity tests after 1 and 3 days. Based on the results, cell viability (neutral red assay), proliferation (BrdU assay), and migration (scratch-wound assay) were evaluated using only the dosimetric parameters recommended for mucositis. Non-irradiated cells served as the control. The experiments were performed in triplicate. The 11 parameters diminished mitochondrial activity and induced tumor cell apoptosis. Using the parameters recommended for mucositis, irradiation with 780 nm (70 mW, 4 J/cm2) proved to be the safest and led to a reduction in cell viability, the induction of apoptosis, and a reduction in the migration capacity of the tumor cells.

Central mucoepidermoid carcinoma: An up-to-date analysis of 147 cases and review of prognostic factors.

OBJECTIVE: To integrate the available data published on central mucoepidermoid carcinoma (CMC) into a comprehensive analysis of its clinical aspects, histology, treatment, and prognostic factors. METHODS: An electronic search was undertaken in July 2017. Eligibility criteria for publications included having clinical, histological, treatment, and time of follow-up data to confirm the diagnosis. RESULTS: In addition, gender, histological grade, conservative treatment, and lymph node metastasis were significant independent prognostic factors. CONCLUSION: Male patients with histological grade III CMC of the jaw bone, who used conservative treatment as the main treatment, and presented with lymph node metastasis, were more likely to have a worse prognosis.

Ki-67 protein predicts survival in oral squamous carcinoma cells: an immunohistochemical study.

The aim of this study was to identify the expression of Ki-67 and MCM3 in oral squamous cell carcinoma (OSCC) as well as to address the correlation with patient survival and clinical features. Samples were collected from 51 patients with OSCC who presented for follow-up. Immunohistochemical expression of Ki-67 and MCM3 in all groups was performed. The scoring system was previous published by Tsurutani in 2005. We used Kappa index to evaluate observers agreement degree. The associations between protein expression and clinical variables were examined for statistical significance using the chi-squared test. The overall survival rates were estimated by the Kaplan-Meier method and the relationship between protein expression and survival was compared using the log-rank test (p < 0.05). The overall survival time for a patient with positive immunostaining for Ki-67 is shorter than for a patient with negative immunostaining, (log-rank test, p = 0.00882). Patients with tumor size T3 and T4 showed a statistically significant relationship with Ki-67 immunoexpression (log-rank test, p = 0.0174). The relationship between Ki-67 expression and the relation between age, gender, smoking, tumor site, lymph node metastasis and disease stage was not significant. The examiners agreement degree by Kappa presented p value < 0.05. There was not a significant correlation when we evaluated MCM3 expression regarding clinical characteristics and survival rate. From these results, the present study suggests that positive Ki-67 expression found in OSCC patients may contribute to predict the survival in OSCC samples, as well as the relation between the protein and the tumor size.

Reduced chromatin acetylation of malignant salivary gland tumors correlates with enhanced proliferation.

BACKGROUND: Epigenetic changes refer to any heritable modification in gene expression independent of alterations in the DNA sequence. Currently, it is well established that epigenetics represents a crucial player for tumor development. Nevertheless, the epigenetic mechanisms involved in the development and progression of salivary gland tumors (SGTs) remain poorly understood. METHODS: In this study, we analyzed the pattern of acetyl-histone H3 (lys9) expression in benign and malignant SGTs and further correlate our results with tumors' proliferative activity and clinical outcomes. We assembled tissue microarrays (TMAs) of 84 cases of SGTs and analyzed for acetyl-histone H3 (lys9) and Ki-67 using immunohistochemistry. The study comprised 42 benign and 42 malignant SGTs. RESULTS: All cases included in this study were positive to acetyl-H3 (lys9). We observed that malignant SGTs were hypoacetylated compared with benign (P = 0.04). Moreover, acetyl-H3 (lys9) expression was inversely correlated with Ki67 (**P = 0.02). CONCLUSION: This study provides the first insight regarding histone modifications in SGTs. Our results suggest that epigenetic mechanism, particularly hypoacetylation of histone H3 (lys9), might play a role in the behavior of salivary gland tumors. Also, our findings suggest that interfering with the acetylation pattern of tumor histones represents a potential novel therapeutic strategy for the treatment of SGTs.

Ki-67 protein predicts survival in oral squamous carcinoma cells: an immunohistochemical study

Abstract The aim of this study was to identify the expression of Ki-67 and MCM3 in oral squamous cell carcinoma (OSCC) as well as to address the correlation with patient survival and clinical features. Samples were collected from 51 patients with OSCC who presented for follow-up. Immunohistochemical expression of Ki-67 and MCM3 in all groups was performed. The scoring system was previous published by Tsurutani in 2005. We used Kappa index to evaluate observers agreement degree. The associations between protein expression and clinical variables were examined for statistical significance using the chi-squared test. The overall survival rates were estimated by the Kaplan-Meier method and the relationship between protein expression and survival was compared using the log-rank test (p < 0.05). The overall survival time for a patient with positive immunostaining for Ki-67 is shorter than for a patient with negative immunostaining, (log-rank test, p = 0.00882). Patients with tumor size T3 and T4 showed a statistically significant relationship with Ki-67 immunoexpression (log-rank test, p = 0.0174). The relationship between Ki-67 expression and the relation between age, gender, smoking, tumor site, lymph node metastasis and disease stage was not significant. The examiners agreement degree by Kappa presented p value < 0.05. There was not a significant correlation when we evaluated MCM3 expression regarding clinical characteristics and survival rate. From these results, the present study suggests that positive Ki-67 expression found in OSCC patients may contribute to predict the survival in OSCC samples, as well as the relation between the protein and the tumor size.

The influence of low-intensity physiotherapeutic ultrasound on the initial stage of bone healing in rats: an experimental and simulation study.

BACKGROUND: Low-intensity physiotherapeutic ultrasound has been used in physical therapy clinics; however, there remain some scientific issues regarding the bone-healing process. The objective of this study was to investigate the influence of low-intensity physiotherapeutic ultrasound on the initial stage of bone healing in rats. METHODS: Twenty-two male adult rats were assessed quantitatively and qualitatively using radiographic, biochemical, and histological analyses. Numerical simulations were also performed. Fractures in animals in the ultrasound group (n = 11) were treated with low-intensity ultrasound (pulsed mode, duty cycle 20 %) for 10 min daily at an intensity of 40 mW/cm2 SATA (1.0 MHz) for 10 days. Fractures in animals in the control group (n = 11) were not treated. RESULTS: Alkaline phosphatase levels were non-significantly higher in the ultrasound group than in the control group in the time intervals considered (t(13) = 0.440; 95 % confidence interval (CI) -13.79 to 20.82; p = 0.67). Between-group serum calcium levels were also not significantly different (t(13) = -0.842; 95 % CI -0.48 to 0.21; p = 0.42). Finally, there were no significant differences in radiological scores between the two groups (U = 118; 95 % CI -1.99 to 1.99; p = 0.72). However, the diameter of the newly formed bone tissue was greater and more evident in the ultrasound group. CONCLUSIONS: Thirteen days after fracture, there was no significant between-group differences in bone-healing processes, although the increased alkaline phosphatase levels and diameter of new bone tissue need to be further investigated.

Metastatic Renal Cell Carcinoma to the Oral Cavity.

Metastases to the oral cavity are extremely rare events, representing less than 1% of all malignant oral tumors. Renal cell carcinoma constitutes about 3% of solid tumors in adults, and it is the most frequent kidney neoplasm, representing about 90% of kidney malignancies. Due to the silent growth of this neoplasm, most patients have no symptoms and the diagnosis is belated, usually after metastases. The present study reports an additional patient of metastatic renal cell carcinoma to the oral cavity regarding the clinical and pathologic features.

Avascular necrosis of the jaws as initial presentation of acute leukemia.

Leukemia is a malignant neoplasm of hematologic origin occurring from disorganized proliferation or increased life span of white cells. The initial manifestations of leukemia are generally signs of bone marrow failure, such as pallor, fatigue, fever, bleeding, and infection related to peripheral blood cytopenias. Few reports have described osteonecrosis, especially in the femoral head, as an initial manifestation of acute lymphoblastic leukemia. To the best of our knowledge, osteonecrosis of the jaw has not been reported as a first sign of leukemia. Here, two cases of osteonecrosis of the jaw as an initial manifestation of acute leukemia are reported, as well as a review of the literature regarding the main oral manifestations of leukemia.

Immunohistochemical expression of WNT5A and MMPs in odontogenic epithelial tumors and cysts.

OBJECTIVE: The aim of this study was compare the expression of WNT5A and MMP2, 7 and 20, in frequent benign odontogenic tumors and odontogenic cysts, since these lesions have a different biological behavior. MATERIALS AND METHODS: Eighty-one paraffin-embedded specimens of odontogenic tumors, including ameloblastoma and keratocystic odontogenic tumor, and thirty-two odontogenic cysts were used for immunohistochemical analysis. RESULTS: The expression of WNT5A in odontogenic tumors and inflammatory cyst was higher than in developmental odontogenic cyst. There was no statistical difference (p<0.05) in the expression of WNT5A when comparing the analyzed tumors. The expression of MMP7 was lower in RC with a statistical difference when compared with all tumors and cysts. Statistical differences also occurred when comparing glandular odontogenic cyst (GOC) to keratocyst odontogenic tumor (KOT) and calcifying cystic odontogenic tumor (CCOT). MMP20 expression was higher in ameloblastoma when compared to adenomatoid odontogenic tumor (AOT), DC and GOC. The expression of MMP20 was lower in CCOT when compared to all tumors and cysts. CONCLUSIONS: The expression of WNT5A in a group of odontogenic lesions suggests the participation of a non-canonical WNT signaling pathway in the progression and maintenance of these lesions. These molecules are possibly involved in the biological differences between odontogenic tumors and cysts. Considering previous studies, WNT5A may help promote the calcification seen in AOT, CCOT and CEOT by activating MMP7.

DNA methyltransferase immunohistochemical expression in odontogenic tumours.

BACKGROUND: Odontogenic tumours are a heterogeneous group of lesions formed from tissues that give rise to the tooth. DNA methylation, a covalent addition of a methyl group to the 5-carbon position of a cytosine nucleotide, is considered an important regulator of gene expression. The addition of the methyl radical is catalysed by DNA methyltransferases (DNMTs). Although some epigenetic studies have been conducted in odontogenic tumours, a study with the three types of DNMTs in several different members of this group is missing. This study analyses the expression of DNMTs in odontogenic tumours. METHODS: Formalin-fixed and paraffin-embedded tissue samples of 20 ameloblastomas, 10 calcifying cystic odontogenic tumours, 10 calcifying epithelial tumours, 10 adenomatoid odontogenic tumours, 10 keratocystic odontogenic tumours, five ameloblastic fibromas, two ameloblastic fibro-odontomas, four central odontogenic fibromas, seven peripheral odontogenic fibromas and 10 odontogenic myxomas were included. Immunohistochemical expression of DNMT1, 3A and 3B was assessed using a semi-quantitative analysis, and also a correlation with p21, p27 and E-cadherin immunoexpression was made. RESULTS: DNMT1, 3A and 3B were expressed in the nucleus and/or cytoplasm of all odontogenic tumours. DNMT1 expression was directly correlated with p27 expression in ameloblastomas. CONCLUSION: The high expression of DNMTs in odontogenic tumour cells suggests methylation as an important mechanism for this group of tumours.

Uso de inibidores de Histona Deacetilase como estratégia terapêutica para sensibilizar células-tronco tumorais a quimioterapia: uma nova visão terapêutica sobre carcinomas mucoepidermoide bucais / Sensitizing Mucoepidermoid Carcinomas to chemotherapy by disrupting the population of Cancer Stem Cells using HDAC inhibitors

Carcinoma mucoepidermóide (CME) é o tumor maligno de glândulas salivares mais comum, representando cerca de 30% dos tumores malignos. O tratamento do CME é a ressecção cirúrgica com eventual radioterapia. Assim, o tratamento do CME pode levar a varias complicações estéticas e funcionais. A quimioterapia tem sido utilizadas apenas em casos recorrentes ou com metástases à distancia. Vários relatos na literatura tem mostrado que o tratamento com drogas isoladas ou combinadas possuem uma resposta insatisfatória e de curta duração em grande parte devido a aquisição de resistência a quimioterapia. Recentemente, a quimiorresistência tem sido relacionada com a presença de Células-Tronco Tumorais (CTT). Essa resistência tem sido associada ao fato de que as essa células são quiescentes e possuem altos níveis de proteínas associadas ao reparo do DNA e baixos níveis das proteínas que levam a apoptose. Recentemente mostrou-se que a resistência a quimioterapia tem sido relacionada com modificações de histonas, uma vez que as células quimiorresistentes possuem núcleo pequeno e baixos níveis de acetilação de histonas, adicionalmente as células sensíveis são relacionadas com núcleo aumentado. O objetivo desse estudo foi avaliar os efeitos do tratamento com IHDAC e cisplatina sobre a população de CTT de CME...

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary tumor compromising about 30% of all salivary malignances. Managing MEC patients remain challenging especially due to the heterogeneous response of tumor cells to available therapy. For this reason clinical outcome remains unpredictable. Current treatment of MEC encompasses surgical resection with eventual adjuvant radiotherapy, which frequently leads to functional and aesthetic complications. The use of chemotherapy is often reserved for recurrent and metastatic tumors. Administration of single-agent or combination therapy has showed activity, however overall response rates are unsatisfactory and of short duration. Emerging evidences suggest that the modest response of tumor cells to therapy resulting in high recurrence rates and poor survival, are associated with the presence of cancer stem cells (CSC). Quiescence of CSC is achieved by the reduced levels of transcription in a process that requires tight folding of DNA driven by core histone proteins. Changes in DNA folding are responsible for different cellular phenotypes mediated by a cell type-specific chromatin organization. Of interest, we also found that acetylation of HNSCC tumor histones driven by histone deacetylase (HDAC) inhibitors abrogate tumor resistance to chemotherapy. We investigate the effects of HDACi and cisplatin in the population of CSCs of MEC...

Anatomical variation of mandibular canal simulating a recurrence of odontogenic tumor.

Mandibular nerve has an important role in the field of oral maxillofacial surgery. Furthermore, several anatomical variations can be found and are clinically relevant mainly in procedures involving the posterior mandible. The unknown of these anatomical variations of the inferior alveolar nerve have been implicated with complications in the performance of surgical procedures and anesthesia in dental and maxillofacial practice. The present paper reports a rare anatomical variation of inferior alveolar nerve mimicking a recurrence of keratocystic odontogenic tumor.