Bone substitute made from a Brazilian oyster shell functions as a fast stimulator for bone-forming cells in an animal model.

Despite their demonstrated biocompatibility and osteogenic properties, oyster shells have been reported as a potential alternative to other commonly used materials for bone substitution. This study evaluated whether an experimental bone substitute (EBS) made from a typical oyster shell of Northeastern Brazil (Crassostrea rhizophora) has effects on bone development using an animal model. Oysters were collected from a biologically assisted vivarium, and their inner layer was used for preparing an EBS. Chemical and surface characterization of EBS was performed using Individually Coupled Plasma Optical Emission Spectrometry (ICP-OES) and Scanning Electron Microscope (SEM), respectively. Seventy-two rats were randomly assigned to groups according to the treatment of bone defects created in the submandibular area: Negative Control (-C), Positive Control (+C; Bio-Oss®) and EBS. Euthanasia occurred at 7, 21, 42 and 56 days postoperatively. The bone pieces were stained with hematoxylin and eosin (H&E). The formation of bone tissue was evaluated histologically and histomorphometrically. Data were analyzed through the Kruskal-Wallis test and ANOVA considering a significant level of 5%. The main element found in EBS was calcium (71.68%), and it presented heterogeneity in the particle size and a porosity aspect at SEM analysis. Histological results revealed the absence of inflammatory cells in all groups, being that EBS presented the most accelerated process of bone formation with a statistically significant difference between this group and the +C and -C groups in the 21-day time-point (p < 0.05). After 21 days, the bone formation process was similar between all groups (p > 0.05), showing an immature lamellar bone pattern after 56 days of experimentation (p > 0.05). Within the limitations of this study, it was possible to conclude that EBS presented good biocompatibility and promoted fast stimulation for bone-forming cells in an animal model.

Screening and early detection of oral cancer: current controversies.

Some evidence suggests that the early detection of oral cancer (OC) during surveillance might improve survival rates. In addition to this, interventions aimed at enhancing public awareness and knowledge of signs, symptoms and risk factors of OC are thought to decrease the burden of disease. Nevertheless, there is much controversy with regard to the cost-effectiveness of population-based strategies for OC screening. Here, we present and briefly discuss timely findings that have put under scrutiny the applicability of approaches targeted at the early identification of patients with OC.

A closer look at strategies for preserving salivary gland function after radiotherapy in the head and neck region.

Radiation-induced damage to the salivary glands remains a major complication of using radiation therapy to treat head and neck cancer, and it has led a wide range of research attempting to resolve the problem. From this perspective, we sought to briefly discuss relevant and timely approaches aimed at protecting or regenerating irradiated salivary glands, thereby preventing the development of salivary hypofunction or rescuing the functional properties of damaged glands. Such findings include molecular, cell, tissue, organ, and drug-based therapies.

Oral microbiome, periodontitis and risk of head and neck cancer.

A wide range of studies has been successfully exploring the association between the human microenvironment, sustained inflammation, and cancer. Growing evidence has then emerged in this field over the past few years. Nevertheless, reliable data addressing the impact of the oral microbiome and periodontitis on the pathogenesis and risk of head and neck malignancies remain scarce. Hence, this communication focuses on briefly discuss the relationship between the oral microbiome, periodontitis and head and neck cancer based on the current understanding of such a disease-associated scenario.

The dentist's role in identifying child abuse: an evaluation about experiences, attitudes, and knowledge.

This study sought to investigate dentists' experiences, attitudes, and knowledge in recognizing and reporting suspected cases of child abuse. It was designed as a cross-sectional study across dental practices. Data were collected through a self-administered questionnaire, which was distributed randomly to 500 dentists. The questionnaire investigated characteristics of the population, education concerning child abuse, experience and attitudes in reporting suspected cases, and the ability to recognize signs of abuse. Approximately 60% of the dentists responded to the survey. Among the dentists who participated in the survey, 87% believed that recognizing child abuse is important, however, 63.2% reported that they did not know how to act in such situations, and 44.2% were unaware of the proper child protection authorities to contact. Among the dentists surveyed, 94.7% reported they did not receive enough education concerning child abuse in their undergraduate studies. While 31.3% of dentists suspected child abuse among their patients, 84% reported their suspicions to the proper authorities. The reason cited most often (33.3%) for not reporting suspected abuse was the fear of litigation and its potential impact on their practice. Only 34.2% of dentists demonstrated knowledge about the potential signs of child abuse.

Immunohistochemical analysis of mismatch proteins in carcinogenesis of the lower lip.

AIM: This study investigated the immunohistochemical expression of hMLH1 and hMSH2 proteins in lower lip squamous cell carcinoma (SCC) and actinic cheilitis (AC), to contribute to the understanding of the development of lower lip cancer. METHODS AND RESULTS: Forty cases of lower lip AC and SCC were studied. Quantitative immunohistochemical analysis was undertaken by counting 1000 cells (positive and negative) in each lesion. Statistical evaluation included Student's t-test and one-way ANOVA. For SCC and AC, the mean number of hMLH1- and hMSH2-positive cells decreased with advanced stage of the lesion. The largest mean number of immunostained cells was observed in AC cases without dysplasia or with mild dysplasia (hMLH1: 721.23 ± 88.116; hMHS2: 781.50 ± 156.93). Intermediate values were obtained for AC with moderate or severe dysplasia (hMLH1: 532.86 ± 197.72; hMHS2: 611.14 ± 172.48). Lower lip SSCs presented the smallest number of positive cells (hMLH1: 255.03 ± 199.47; hMHS2: 518.38 ± 265.68). A statistically significant difference was observed between groups (P < 0.001). CONCLUSIONS: The results support the hypothesis that changes in the immunoexpression of these mismatch proteins are related to the process of carcinogenesis of the lower lip.

Longitudinal assessment of immunological and oral clinical conditions in patients undergoing anticancer treatment for leukemia.

OBJECTIVE: The aim of this study was to evaluate the evolution of the immunological and oral clinical conditions of children and adolescents undergoing anticancer treatment for leukemia (ATL). METHODS: Twenty patients aged 3-15 years undergoing chemotherapy seen at a referral center for cancer treatment in the State of Maranhão, Brazil, from 2008 to 2009, were evaluated at baseline (1st). Twenty-two controls were selected in public schools. Oral lesions, caries experience (deft and DMFT), plaque index (PI), gingival index (GI) and salivary IgA were analyzed. Patients and controls were evaluated after 6 months (2nd). The Shapiro Wilk, Mann-Whitney, Wilkoxon and Spearman correlation tests were carried out (alpha=5%). RESULTS: Gingivitis and mucositis were the most frequent manifestations in oral mucosae during the two phases. The mean DMFT index increased from 3.9 ± 4.2 (1st) to 4.4 ± 4.3 (2nd) (p = 0.04). The mean deft index was the same in the 1st (1.9 ± 2.7) and 2nd (1.9 ± 2.7) evaluation (p = 0.86). The GI also did not vary between assessments: 1st (1.3 ± 0.4) and 2nd (1.3 ± 0.3) - (p = 0.12), except on the lingual and distal surfaces, where increased from the 1st to 2nd evaluation (p < 0.01). The PI varied from 0.9 to 1.1, but this difference was not significant (p = 0.48), except for the lingual surface, where increased from 0.6 to 1.0 (p = 0.04). There was a reduction in salivary IgA levels from 2.9 to 1.9 µg/mL (p = 0.04), and mean IgA was significantly higher in the control group (5.4 µg/mL) if compared to cases (p < 0.01). CONCLUSION: The clinical and immunological oral conditions of children and adolescents undergoing ATL presented an unfavorable evolution. This study highlights the need for monitoring oral conditions during the ATL and draws attention to the additional responsibility of the otolaryngologist in referring ATL patients to the dentist, especially in the presence of clinical evidence of oral problems. We suggest that the planning of ATL take into account the oral health, in a multidisciplinary oncology team.

Role of integrins in the carcinogenesis of squamous cell carcinoma of the tongue and lower lip.

OBJECTIVE AND METHODS: This study analyzed the distribution, intensity, and pattern of immunohistochemical expression of α2ß1, α3ß1, and α5ß1 integrins in squamous cell carcinoma (SCC) of the lower lip and tongue to identify biomarkers that reflect the clinical course of this cancer. Immunoexpression was compared considering prognostic parameters such as anatomic site, metastasis, and histologic grade of malignancy. RESULTS: Immunohistochemical analysis at the invasion front showed a predominance of granular cytoplasmic expression of the integrins studied. In most cases, immunopositive cells were diffusely distributed in the tumors, irrespective of their location, except for α3ß1 integrin-positive cells which were focally distributed in 53.3% of tongue SCC cases. With respect to staining intensity, positive staining for α2ß1 integrin was observed in 80% of lower lip SCCs and in 93.3% of tongue SCCs. Staining for α3ß1 integrin was moderately positive in 60% of lower lip and tongue SCCs. The staining intensity of α5ß1 integrin was moderately and strongly positive in 53.3% and 46.7% of lower lip SCCs, respectively, and in 46.7% and 53.3% of tongue SCCs. CONCLUSIONS: The strong immunoreactivity for integrins α2ß1, α3ß1, and α5ß1 seen in the oral SCC cases studied suggests a significant participation of these proteins in oral carcinogenesis. However, their expression does not reflect the clinical course of this cancer.

Oral manifestations as important symptoms for juvenile dermatomyositis early diagnosis: a case report.

BACKGROUND: Juvenile dermatomyositis (JDM) is an idiopathic inflammatory myopathy of childhood and adolescence, characterized by symmetrical weakness of proximal muscles and classical cutaneous features. Literature reports rarely describe or focus on oral lesions that are associated with this disease. CASE REPORT: This case describes a 4-year-old girl in whom the oral lesions were the initial manifestations of JDM. Physical examination revealed characteristic skin manifestations, proximal muscle weakness, extensive calcinosis, necrotic ulceration, complicated erysipelas, and diffuse alopecia. The diagnosis was established based on the clinical, histological, electroneuromyography, and biochemical findings. CONCLUSION: Recognition of gingival telangiectases as an important diagnostic marker of JDM leads us to suggest that identifying oral manifestations, which may be carried out by a paediatric dentist, contributes in establishing an early diagnosis and an immediate treatment of this condition.

Changes in immunoexpression of E-cadherin and beta-catenin in oral squamous cell carcinoma with and without nodal metastasis.

The aim of this study is to analyze the immunohistochemical expression of E-cadherin and beta-catenin in oral squamous cell carcinoma to better understand the biological behavior of this lesion. The sample consisted of 15 cases of the tongue and 15 of the lower lip. The pattern and intensity of the labeling and the analysis of the percentage of tumor cells immunopositive in membrane for E-cadherin and beta-catenin were related to the anatomic location of the lesion, the presence or absence of nodal metastasis, and the histological gradation of malignancy in the tumor invasion front. The presence or absence of cytoplasmic and nuclear labeling was also recorded. The membrane expression for E-cadherin and beta-catenin predominately displayed a heterogeneous pattern in the carcinomas studied. No significant difference was observed between the expression pattern and the quantity of cells immunopositive for E-cadherin and beta-catenin and the anatomic location of the lesion or the presence or absence of nodal metastasis. However, a statistically significant difference was found between the reduced expressio\n of these proteins and the high malignancy score. The reduced immunoexpression of these proteins in the membrane may be related to the high degree of cell indifferentiation in cases of oral squamous cell carcinoma with high scores.