Revisiting the metallothionein genes polymorphisms and the risk of oral squamous cell carcinoma in a Brazilian population.

BACKGROUND: Metallothioneins (MTs) gene polymorphisms have been associated with the ability of free radical scavenging and detoxification of heavy metals leading to cancer development. Our aim was to revisit, in a Brazilian population, single-nucleotide polymorphisms (SNPs) of the MT gene family previously associated with oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: A case-control investigation with 28 OSCC patients and 45 controls was conducted, using conventional risk factors (tobacco use and alcohol consumption) as covariates. SNPs genotyping for rs8052334 (MT1B), rs964372 (MT1B), and rs1610216 (MT2A) was performed by PCR-RFLP, and SNPs for rs11076161 (MT1A) were analyzed by TaqMan assay. RESULTS: The only SNP associated with increased risk for OSCC was the MT-1A AA genotype (OR = 4.7; p = 0.01). We have also evidenced for the first time a significant linkage disequilibrium between the SNPs of MT-2A and MT-1A in this population with the highest frequency (30%) of the unfavorable haplotype G/A/C/T (rs1610216 / rs11076161 / rs964372 / rs8052334) of MT gene polymorphisms (OR = 6.2; p = 0.04). Interestingly, after removing the effects of conventional risk factors, we have uncovered the significance of the AA genotype of the rs11076161 with increased odds of 19-fold higher towards OSCC development. CONCLUSIONS: This is the first demonstration that a significant linkage disequilibrium among gene polymorphisms of the MT family may affect susceptibility to oral cancer, which is conditioned by the G/A/C/T haplotype (rs1610216/rs11076161/rs964372/ rs8052334) and the MT-1A gene polymorphism has a potential clinical utility for the OSCC risk assessment.

Simple bone cyst: description of 60 cases seen at a Brazilian School of Dentistry and review of international literature.

BACKGROUND: The aim of this study was to describe the relative frequency and the main demographic and clinic-radiographic features related to patients diagnosed with Simple bone cyst (SBC) in an Oral Diagnosis Service in Southeast Brazil and present a review and discussion of international literature on this topic. MATERIAL AND METHODS: SBC cases from our service encompassing the period between 1978 and 2017 were selected. In addition, a literature search was performed in the Pubmed/MEDLINE online electronic database published between 1951 and 2019. RESULTS: A total of 2,459 cystic lesions were documented in our service, thus 60 patients were diagnosed with the SBC representing 2.4% of all jaw cystic. Most of cases were asymptomatic. Multiple SBC lesions were seen in two patients (3.4%) and association with cemento-osseous dysplasia was seen in one female patient (1.7%). A total of 793 cases were enrolled in this literature review. CONCLUSIONS: The SBC is an asymptomatic lesion often discovered in routine image exams in young patients. The unilocular, well defined margin with scalloped appearance is characteristic and helps the definition of diagnosis. This review suggests a different epidemiologic trend concerning to the sex and it confirms the posterior region of mandible as the more frequent location. The conservative treatment with limited exploration and curettage remains as the gold-standard treatment.

Differential metallothionein expression in oral lichen planus and amalgam-associated oral lichenoid lesions.

BACKGROUND: Oral lichen planus (OLP) is a chronic inflammatory disease mediated by T cells, which manifests as reticular (white) or erosive (red) lesions, that are eventually painful. Oral lichenoid lesion (OLL) are distinguished from OLP by the presence of precipitating factors. The aim of this study was to evaluate whether the presence of metallothionein, which is involved in anti-apoptotic pathways and the anti-oxidative response, could serve as a differential diagnostic for OLP and OLL. MATERIAL AND METHODS: We evaluated the expression of metallothionein in 40 cases of OLP and 20 cases of OLL using immunohistochemistry. RESULTS AND CONCLUSIONS: White OLP has higher concentrations of metallothionein than red OLP in basal and parabasal layers. Moreover, metallothionein was more frequently observed in the cytoplasm and nuclei of basal cells in OLP patients compared to the same regions of OLL cases. Metallothionein levels are related to OLP severity and may contribute to a differential diagnosis between OLP and OLL.

Adenoid cystic carcinoma of the maxillary sinus: a clinical-pathological report of 10 years of experience from a single institution.

Adenoid cystic carcinoma (ACC) is the most common malignant salivary gland tumour of the maxillary sinus. The present study describes 24 cases seen over a period of 10 years at the Brazilian National Cancer Institute. Socio-demographic, clinical, pathological, and follow-up data were retrieved from the medical files for the period 1997-2006. The mean age of the patients was 51.1 years. Twenty-one (87.5%) presented advanced tumours. The main signs and symptoms found were a tumour mass (87.5%), pain (50%), nasal obstruction (25%), and epistaxis (20.8%). Most cases (62.5%) were treated with surgery and radiation therapy. Follow-up data showed two patients (8.3%) with residual disease, local recurrences in four (16.7%) patients, and distant metastasis in five (20.8%). The overall 5- and 10-year survival rates were 72.61% and 62.11%, respectively. Maxillary sinus ACC has an aggressive but indolent behaviour, typically presenting at an advanced T stage that reflects a poor prognosis for patients.

Synthesis and characterization of zinc oxide nanocrystals and histologic evaluation of their biocompatibility by means of intraosseous implants.

AIM: To synthesize and characterize zinc oxide (ZnO) nanocrystals and assess their biological properties for applications in dentistry, particularly in endodontics, by means of intraosseous implants. METHODOLOGY: ZnO nanocrystals were synthesized and characterized by micro-Raman spectroscopy and X-ray Diffraction. Ten guinea pigs were divided into two groups representing experimental periods of 4 and 12 weeks and received implants on both sides of the mandible in the region of the symphysis. The connective tissue response along the lateral wall outside the cup served as the negative control. The animals were euthanized at the end of each observation period and prepared for routine histological examinations which evaluated inflammatory response and material biocompatibility. RESULTS: ZnO nanocrystals were highly pure, crystalline, and averaged 21 nm in size. After 12 weeks, tissue analysis revealed the presence of a thin layer of connective tissue with some giant cells between the implanted material and underlying bone tissue. While signs of mild inflammation could be seen, bone resorption and remodeling were not apparent. CONCLUSION: ZnO nanocrystals were biocompatible, well tolerated and allowed new bone formation and bone remodelling.

Metastatic tumours to the head and neck: retrospective analysis from a Brazilian tertiary referral centre.

Data regarding the development of head and neck metastases are limited, with the majority of the studies focusing on single cases affecting mainly the oral cavity and surrounding tissues. This study describes the incidence of head and neck metastases from primary tumours originating elsewhere. The medical records of selected patients were reviewed, and socio-demographic data as well as information about the localization of the primary tumours and their metastases to this region, treatment modalities employed, follow-up, and outcomes were collected. A total of 24 cases were found. The mean age at diagnosis was 52.1±17.6 years and the male to female ratio was 1:1.4. Most primary tumours were located in the lung and breast. The overall 1-, 2-, and 5-year survival rates were 63.0%, 39.1%, and 19.6%, respectively. Radiotherapy for the metastatic focus significantly prolonged the survival time of the patients (P=0.048). Cervical lymph node metastases are a common event in patients with primary tumours growing elsewhere.

Odontogenic tumours: 240 cases diagnosed over 31 years at a Brazilian university and a review of international literature.

This study describes the epidemiology and clinical presentation of odontogenic tumours (OT) seen at a regional Brazilian oral and maxillofacial pathology service; to assess the quantitative impact of the most recent World Health Organization (WHO) classification of these lesions; and to compare this series with others available in international databases. The study was carried out by retrospectively analysing 240 cases diagnosed from 1978 to 2009, followed by a comprehensive review of the literature. The patients' mean age was 29 years, with a male to female ratio of 1:1.1. Benign lesions comprised 97.9% of the cases (mostly keratocystic odontogenic tumours (KCOT), odontomas and ameloblastomas) with the remaining tumours depicting a prevalence of less than 5%. Adenomatoid OT were less frequent than in most previous studies, while malignant OT were strikingly numerous. Most OT in children and in the anterior maxilla were odontomas, while maxillary ameloblastomas were rare. Lack of swelling was more frequent in KCOT than in ameloblastomas. The present study confirms the relative impact of KCOT in the epidemiology of OT and identifies more similarities between the present series with reports from the United States and Europe than with African and Asian populations.

Small cell carcinoma of the salivary gland: a systematic literature review and two case reports.

Salivary gland small cell carcinoma is a rare neoplasm, accounting for less than 1% of salivary gland tumours. Little is known about the epidemiologic factors and treatment of this lesion. The authors report two cases and perform a systematic literature search from 1960 to 2011 for articles on salivary gland small cell carcinoma. Once the papers were reviewed, a database was generated to analyse clinical and pathological features, treatments and outcomes, and an attempt was made to identify prognostic factors. Available data were retrieved for 44 cases which fully satisfied the inclusion criteria; the median age was 64.25 years and the male:female ratio was 2.4:1. The parotid gland was the most common site (79.6%). The overall 1-, 2- and 5-year survival rates were 75.3%, 56.4% and 36.6%, respectively. According to the present review, patient age, tumour size, distant metastasis and cytokeratin-20 positive immunostaining were all significant prognostic factors in a univariate analysis. No particular treatment approach appeared to improve survival. This work reinforces knowledge about salivary gland small cell carcinoma's epidemiologic features, and identifies new prognostic markers. The optimal management of this lesion remains controversial.

Oral phaeohyphomycosis.

This is the first description of solitary phaeohyphomycosis affecting the mucosal surface. The lesion developed in the inferior lip of a 57-year-old woman. After surgical resection, histopathological examination evidenced characteristic brownish fungal structures within granulomatous-purulent inflammation. Amplification and sequencing of rDNA obtained from paraffin-embedded tissue identified Alternaria species, as the causative agent.

Apoptosis in epithelial cells of apical radicular cysts.

AIM: To investigate the occurrence of apoptotic cell death in the epithelium of radicular cysts and to compare its frequency in lesions presenting a distinct functional state. METHODOLOGY: Twenty radicular cysts were selected and arranged into two groups with 10 lesions in each group: atrophic (quiescent) and hyperplastic (active) epithelium. Morphologic investigations of apoptosis were conducted by means of optic microscopy in haematoxylin and eosin slides. Immunohistochemical techniques to detect the bcl-2 protein were carried out by streptavidin-biotin-peroxidase assay. In both instances, 30 sequential high-power microscopic fields were observed to determine apoptotic (AI) and bcl-2 immunostaining (bcl-2I) indexes. The presence of AI and bcl-2I within the two groups was compared using the t-test. Correlation between the AI and the bcl-2I was investigated using the Spearman test. RESULTS: Apoptosis was detected in the epithelium of all cysts. Higher AI levels were found in lesions with an atrophic (0.17 +/- 0.19) rather than a hyperplastic (0.10 +/- 0.10) epithelium. The same was found for the bcl-2I levels (0.06 +/- 0.03 vs. 0.04 +/- 0.01, respectively). However, these differences were not statistically significant. A positive and significant correlation was found between AI and bcl-2I. CONCLUSIONS: Apoptosis was always present in the epithelium of the lesions and was more frequent in lesions with atrophic (quiescent) epithelium.

Unicystic ameloblastoma: a possible pitfall in periapical diagnosis.

AIM: To report a clinical case of unicystic ameloblastoma previously misdiagnosed as radicular cyst. SUMMARY: A 49-year-old white male was referred to a private practitioner complaining of an asymptomatic bony hard swelling of the left posterior mandible. The patient's dental history indicated that his left mandibular first molar had been extracted approximately 10 years previously. At that time, preoperative radiographic examination demonstrated a radiolucent area of 1.5 cm diameter with well-defined margins involving the distal root of tooth 36. The lesion was diagnosed as cystic and surgery for its removal was advised, but not performed. At presentation, radiography demonstrated a well-defined 3 cm diameter radiolucency extending from the second premolar to the second molar. The lesion was enucleated and histopathological examination confirmed a diagnosis of unicystic ameloblastoma. KEY LEARNING POINTS: *Despite a clinical diagnosis of periapical disease of endodontic origin, a nonendodontic lesion may be present. *Unicystic ameloblastoma located on the periapical area of a tooth can lead to a pulp-periapical misdiagnosis, and should be considered in differential diagnosis. *All tissue specimens recovered in apical surgery should be submitted to histopathological analysis.

A comparative histological evaluation of the biocompatibility of materials used in apical surgery.

AIM: To evaluate the biological properties of a variety of materials that could be used in apical surgery. METHODOLOGY: The intraosseous implant technique recommended by the FDI (1980) and ADA (1982) was used to test the following materials: zinc oxide-eugenol (ZOE), mineral trioxide aggregate (MTA), and Z-100 light-cured composite resin. Thirty guinea-pigs, 10 for each material, divided into experimental periods of 4 and 12 weeks, received one implant on each side of the lower jaw symphysis. The connective tissue response alongside the lateral wall outside the cup served as a negative control for the technique. At the end of the observation periods, the animals were killed and the specimens prepared for routine histological examination to evaluate their biocompatibility. RESULTS: The reaction of the tissue to the materials diminished with time. The ZOE cement was highly toxic during the 4-week experimental period, but this profile changed significantly after 12 weeks, when it showed biocompatible characteristics. MTA and Z-100 showed biocompatibility in this test model at both time periods. CONCLUSIONS: MTA and Z-100 composite were biocompatible at 4 and 12 weeks in this experimental model.

Levels of GM-CSF, IL-3, and IL-6 in fluid and tissue from human radicular cysts.

Cytokines released by immune system cells play an important role in cyst enlargement. This study aimed to determine, by ELISA, the levels of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin 3 (IL-3), and IL-6 in fluid and tissue from human radicular cysts. GM-CSF was found in 42.8% of the fluid samples (164.3 pg/mL) and IL-6 in 92.8% (641.4 pg/mL). No IL-3 was detected in any fluid samples. In the tissue samples, 28.6% were positive for IL-3 (369.2 pg/mL), 86.4% for IL-6 (92.4 pg/mL), and 95.8% for GM-CSF (200.5 pg/mL). It can be concluded that GM-CSF and IL-6 were widely found in the fluid and tissue samples. In contrast, IL-3 was found only in the cystic tissue, even though in few lesions. These cytokines may contribute to the inflammation, cystic growth, and bone resorption that characterize cystic lesions.

Exfoliative cytology: a helpful tool for the diagnosis of paracoccidioidomycosis.

OBJECTIVE: To describe the main cytological findings associated with smears collected from oral lesions of paracoccidioidomycosis and to appraise the use of cytology as a diagnostic tool for the disease. STUDY DESIGN: Cytological smears and biopsies were collected from 40 lesions with a clinical suspicion of paracoccidioidomycosis. Evaluation of the sensitivity, specificity, positive and negative predictive values, accuracy and the positive likeness ratio of the oral smear when compared with the histological diagnosis, was performed. The latter is considered the 'gold standard' for comparison. RESULTS: The main morphological findings were the rounded-shaped, birefringent and multiple-budded fungi, Langhans' giant cells and epithelioid cells. The following associative measures were found: sensitivity, 67.9%; specificity, 91.7%; positive predictive value, 95.0%; negative predictive value, 55.0%; accuracy, 75.0%; and positive likeness ratio, 8.14. CONCLUSION: The cytological findings of paracoccidioidomycosis are characteristic and cytology is accurate in the diagnosis of the disease. Positive patients should be treated. Negative patients should be submitted to biopsy to confirm or to dismiss the diagnosis of this mycosis.

Mucus extravasation phenomenon in newborn babies: report of two cases.

Two rare cases of congenital mucoceles in newborn babies are reported. The patients presented with nodular swellings on their lower lips at birth with no obvious local aetiology. In both cases the mucoceles interfered with normal feeding. The lesions were excised by surgical approach under general anaesthesia and histopathological examination confirmed the lesions to be extravasation-type mucoceles. The article includes a brief discussion of the epidemiology and ethiopathogeny of mucoceles.

AgNOR count in exfoliative cytology of normal buccal mucosa. Effect of smoking.

OBJECTIVE: To compare the argyrophilic nucleolar organizer region (AgNOR) count of cells collected from normal buccal mucosa of cigarette smokers with that obtained from nonsmokers. STUDY DESIGN: Cytologic smears of normal buccal mucosa from 20 smokers and 20 nonsmokers were stained for AgNORs. The AgNOR count was established on 100 cells. The count values of groups were compared and analyzed using Student's unpaired t test. RESULTS: The AgNORs were round and had a clustered distribution in both groups. The mean AgNOR count was statistically higher in cells of smokers than nonsmokers (P < .01). CONCLUSION: Analysis of AgNORs suggests that cigarette smoking influences proliferative activity in cells of normal buccal mucosa.

Intraosseous leiomyoma of the mandible.

An intraosseous leiomyoma arising within the mandible was diagnosed in a 24-year-old woman. Clinically, a nodular swelling of the lower border of the mandible was noted. Radiographically, a unilocular ellipsoid radiolucency, loss of the lower border of the mandible, and tooth resorption were observed. The mitotic count was 0.4 per 10 high-power fields, which supported the benign nature of the tumor. The clinical and histologic parameters for distinguishing between benign and malignant smooth muscle neoplasms are discussed.