Objective. The aim of this study was to evaluate the immunohistochemical expression of collagen IV, matrix metalloproteinase (MMP) 9 and tissue inhibitor of MMP (TIMP) 2 in dentigerous cysts (DCs), radicular cysts (RCs), keratocystic odontogenic tumors (KOTs), and ameloblastomas. Study design. Twenty cases of DCs, 20 RCs, 20 KOTs, and 20 ameloblastomas were selected and analyzed by immunohistochemistry. Results. Most DCs and RCs showed continuous and Ͼ50% staining for collagen IV in the basement membrane of the epithelium, whereas predominantly discontinuous thin and Յ50% staining was observed in KOTs and ameloblastomas, with a significant difference in staining percentage (P Ͻ .001). MMP-9 was diffusely distributed and localized in both epithelial and mesenchymal cells of all of the lesions analyzed. The staining percentage was higher in the epithelium (P ϭ .058) and mesenchyme (P ϭ .005) of KOTs and ameloblastomas. Moreover, the distribution pattern, location, and percentage of expression of TIMP-2 were similar in the lesions studied, except for ameloblastoma, with a significant difference in staining percentage (P Ͻ .001).Conclusion. These results demonstrate that the interaction between collagen IV, MMP-9, and TIMP-2 is an important factor for the establishment of differences in the biologic behavior of the odontogenic cysts and tumors studied. Factors related to the epithelial and mesenchymal components participate in the regulation of the growth of odontogenic cystic lesions and tumors. 1 The altered expression of specific proteins of the extracellular matrix (ECM), associated with the exuberant presence of matrix metalloproteinases (MMPs) and the absence of expression of metalloproteinase inhibitors (TIMPs), may influence the behavior of these lesions. In the case of tumors, this situation contributes to the growth and higher aggressiveness of the tumor. 2 The odontogenic keratocyst, recently reclassified as keratocystic odontogenic tumor (KOT), 3 is known for its aggressive nature and high rate of recurrence, especially compared with other odontogenic cysts. 4 Ameloblastoma is a locally aggressive benign epithelial odontogenic tumor with a marked invasion potential that results in multiple recurrences after enucleation and curettage. 5 In contrast, dentigerous (DC) and radicular (RC) cysts show an indolent behavior and rarely recur after surgical removal. KOT presents a cystic structure similar to that of DC and RC, but its invasive and destructive growth is similar to that of ameloblastoma. 6 KOT, ameloblastoma, DC, and RC show distinct evolutions and biologic behaviors. In view of this fact, a growing number of studies have tried to identify

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Introduction and objective: The peripheral and central giant cell lesions (PGCL and CGCL) are a group of pathological entities with similar histopathological features and whose origin has not been fully elucidated. The former is reactive and the latter exhibits a nonneoplastic proliferative behavior. This article aims to review the literature on peripheral giant cell lesions (PGCL) and central giant cell lesions (CGCL) by discussing the most important aspects pertaining to each of them. Results: These lesions are found in different locations and show diverse clinical signs despite having the same histopathological features. The treatment consists in the surgical resection by different techniques depending on the type of the lesion and clinical conditions. In the case of CGCL, drug therapy may also be employed. Conclusion: Although there is no consensus in the literature, it is essential to know the etiology of these lesions as well as the exact origin of the giant cells. Due to their singular biological behavior, it is of utmost importance to establish a differential diagnosis between the two lesions and other processes that have similar clinical, radiological and histological characteristics, inasmuch as this procedure is essential to provide a suitable treatment and establish a prognosis.

Cryopreservation aims to cease all biological functions of living tissues in a reversible and controlled manner, i.e., to permit the recovery of cells by maintaining a high degree of their viability and functional integrity. The objective of this study was to evaluate in vitro the influence of cryopreservation on undifferentiated mesenchymal cells derived from the periodontal ligament of human third molars. Mesenchymal cells were isolated from six healthy teeth and cultured in α-MEM medium supplemented with antibiotics and 15% FBS in a humid atmosphere with 5% CO(2) at 37°C. The cells isolated from each tooth were divided into two groups: group I (fresh, non-cryopreserved cells) was immediately cultured, and group II was submitted to cryopreservation for 30 days. The rates of cell adhesion and proliferation were analyzed in the two groups by counting the cells adhered to the wells at 24, 48 and 72 h after plating. The number of cells per well was obtained by counting viable cells in a hemocytometer using the Trypan blue exclusion method. Differences between groups at each time point were evaluated by the Wilcoxon test. The Friedman test was used to determine differences between time points and, if detected, the Wilcoxon test with Bonferroni correction was applied. The results showed no significant difference in the in vitro growth capacity of undifferentiated mesenchymal cells between the two groups. In conclusion, cryopreservation for 30 days had no influence on periodontal ligament mesenchymal cells.

Purpose: Oral squamous cell carcinomas have the potential for rapid and unlimited growth. Therefore, hypoxic tissue areas are common in these malignant tumors and contribute to cancer progression, therapy resistance, and poor outcomes. The aim of the present study was to analyze the gene product distribution of hypoxia-inducible factor-1a (HIF-1a) and glucose transporter-1 (GLUT-1) in cases of tongue squamous cell carcinoma (TSCC) and to identify a preliminary correlation between these proteins and clinical staging and Brynes's histologic grading system (HGS). Materials and Methods:The sample included 57 cases of TSCC. Histologic sections of 3 mm were submitted to the immunoperoxidase method and semiquantitative analysis. The association between HIF-1a and GLUT-1 expression in TSCC and the clinical stage and the HGS of Bryne (1998) was evaluated using the c 2 test, with the significance level set at 0.05 (a = 0.05).Results: HIF-1a was mainly expressed in the nucleus/cytoplasm of neoplastic cells, most specimens exhibited diffuse staining in neoplastic cells (84.2%), and focal staining was only observed in perinecrotic areas (15.8%). GLUT-1 was expressed in the cytoplasm and membrane of malignant cells, and diffuse staining was observed in all cases. The intensity of HIF-1a expression correlated significantly with clinical stage (P = .011) and HGS (P = .002). A significant association was observed between the distribution of HIF-1a expression and metastasis (P = .040). Immunoexpression of GLUT-1 correlated significantly with clinical stage (P = .002) and HGS (P = .000). GLUT-1 expression in the peripheral island was predominant in most low-grade tumors (78.6%); in the high-grade cases, the expression prevailed in the location center/periphery (55.8%). Comparison of the location of the tumor island in the different histologic grades showed a statistically significant difference (P = .025).

The objective of this study was to assess angiogenic activity by analyzing anti-CD105 and anti-CD34 immunostaining in 20 cases of vascular malformations (VMs) and 20 cases of oral pyogenic granulomas (OPG). In addition, the usefulness of these markers for the differential diagnosis of these two oral tumors was evaluated. The results showed no significant difference in mean microvessel count between the anti-CD105 (P = 0.803) and anti-CD34 (P = 0.279) antibody. The mean number of vessels was 18.75 and 59.72 for oral VMs immunostained with anti-CD105 and anti-CD34 antibody, respectively, whereas in OPG the mean number was 20.22 and 48.09, respectively. CD34 was found to be more effective than CD105 in identifying blood vessels. However, the anti-CD105 antibody seems to be more related to vascular neoformation. Overall, this study supports the role of angiogenic factors in the etiopathogenesis of oral VMs and PG, but the results showed that quantification of angiogenesis cannot be used as a marker for the differential diagnosis of these two types of lesions.

RESUMO Objetivo: Realizar uma discussão a cerca das principais alterações morfofisiológicas que ocorrem com o envelhecimento e a repercussão destas na maneira como os cirurgiões-dentistas irão atender a estes pacientes. Afinal, nos últimos anos, o constante aumento da população idosa no Brasil fez com que a saúde do idoso ganhasse ênfase no cenário nacional. Material e Métodos: A busca dos artigos para esta revisão usou as bases de pesquisa online: PubMed/ MEDLINE, LILACS, BBO, Scielo e Science Direct. Como estratégias de busca utilizou-se as palavras "geriatric" e "dentistry" e limitou-se a um período de cinco anos, de 2006 a 2011. Resultado: Constatou-se que as alterações morfofisiológicas orais que mais prevalecem no paciente idoso são a xerostomia, a perda da capacidade gustativa, alterações no periodonto, o déficit motor que leva à dificuldade de higienização bucal, perdas dentárias e lesões em mucosa. Além disso, a saúde bucal desempenha um importante papel na qualidade de vida destes pacientes. Conclusão: O odontólogo deve aprender sobre os cuidados específicos que a população idosa necessita e entender que o atendimento desta parcela da população deve ser empregado sob uma visão mais abrangente, visto que esta pode trazer consigo um conjunto de patologias sistêmicas que interferem na saúde bucal.

Introdução: Os traumatismos dento-alveolares (TDA) podem ser definidos como lesões que são causadas por impactos nos dentes e/ou tecidos duros e moles no interior e/ou exterior da cavidade bucal. Objetivo: Realizar uma revisão de literatura revisão de literatura acerca dos traumatismos dento-alveolares. Serão abordados, de forma geral, os principais índices epidemiológicos, etiologia, formas de diagnóstico e classificação dos traumatismos dento-alveolares.  Métodos: Realizou-se uma busca bibliográfica na base de dados PubMed/ Medline, Scielo e Google acadêmico, tendo como filtro publicações dos últimos 10 anos. A busca foi realizada com descritores previamente selecionados. A pesquisa ocorreu em 3 fases e os artigos foram incluídos obedecendo aos critérios de inclusão e exclusão. Resultados: As lesões por TDA podem acometer crianças, adolescentes e adultos, porém, são bastante comuns durante a infância. Os dados sobre a prevalência variam e as causas mais frequentes são quedas, acidentes esportivos (ciclismo), acidentes de trânsito e violência física. A conduta realizada nesses casos interfere diretamente nos resultados do tratamento, por isso, é importante que o cirurgião-dentista possua conhecimentos adequados sobre como agir frente a essas lesões. Conclusão: Os traumatismos dento-alveolares são lesões vistas rotineiramente na prática clínica odontológica.  A realização de um adequado diagnóstico é fundamental para que o tratamento seja efetivo e o paciente apresente o melhor prognóstico possível.