Resumo Introdução Os ameloblastomas (AM) são considerados os tumores odontogênicos mais comuns da cavidade bucal, apresentando grande importância clínica devido à sua agressividade, capacidade infiltrativa e comportamento recorrente. De maneira semelhante, o ceratocisto odontogênico (CO) desperta a atenção por ter um comportamento agressivo e altas taxas de recorrência em relação aos outros cistos de desenvolvimento. Objetivo Avaliar e comparar o índice de proliferação epitelial e a presença de miofibroblastos em CO e AM, por meio dos anticorpos Ki-67 e α-SMA, respectivamente. Metodologia Foram selecionados 15 casos de AM e 24 casos de CO para investigação imuno-histoquímica das proteínas Ki-67 e α-SMA. Um grupo de sete folículos pericoronários (FP) foi incluído como controle de tecido odontogênico normal. A média de células positivas foi calculada para cada marcador. Resultado O teste de Kruskal-Wallis revelou que a expressão de ambos os marcadores foi maior nos casos de CO, quando comparada à expressão em AM e FP. Segundo o teste de Mann-Whitney, a expressão dos marcadores foi semelhante entre os subtipos de AM. Conclusão A alta expressão de Ki-67 e α-SMA observada em CO poderia estar associada ao comportamento agressivo desta lesão em relação aos outros cistos de desenvolvimento. Por outro lado, a expressão semelhante destas proteínas nos casos de AM e FP, assim como nos subtipos de AM, poderia indicar que outros fatores, além do potencial proliferativo, estariam associados ao comportamento clínico agressivo do AM.

Abstract Introduction Ameloblastomas (AM) are considered the most common odontogenic tumors, with great clinical importance linked to its locally aggressive, infiltrative, and recurrent behavior. The odontogenic keratocyst (OK) represents a peculiar cyst that also draws attention because of its aggressive behavior and high rates of local recurrence. Objective The aim of this study was to evaluate the cell proliferation index and the presence of myofibroblasts in AM and OK using Ki-67 and α-SMA antibodies, respectively. Methodology Fifteen cases of AM and 24 cases of OK were selected for immunohistochemical investigation of the proteins α-SMA and Ki-67. A group of 7 pericoronal follicles (PF) was included as control for normal odontogenic tissue. The mean percentage of positive cells was calculated for each protein. Result Kruskal-Wallis test for both markers showed that expression was higher in OK, when compared to AM and PF. Mann-Whitney test showed no statistical difference when comparing the expression of both markers between the subtypes of AM. Conclusion Elevated expression of Ki-67 and α-SMA in OK may be associated with the aggressive clinical behavior of this cyst in comparison to other development cysts. The similar expression of the markers observed among AM and PF cases, as well as among subtypes of AM, may indicate that other factors, besides proliferative potential, are associated with the aggressive behavior of AM.

Odontogenic tumors (OTs) are lesions that develop exclusively on maxillary bones, and form a heterogeneous group. They vary from hamartomatous lesions to benign and malign tumors. Although they are rarely observed in dentistry clinics, it is extremely important for the dentist to be aware of them. The aim of this study was to investigate the incidence of odontogenic tumors diagnosed in the population of Florianópolis, Santa Catarina, Brazil. Cases of odontogenic tumors were selected from the anatomopathological diagnostic services at Federal University of Santa Catarina from 1998 to 2011. Clinical data on these cases were collected from biopsy reports and patient files. Seventy-eight cases of odontogenic tumors were surveyed. Of these diagnoses, 51% were keratocystic odontogenic tumors (KCOTs); the remaining cases were mainly ameloblastomas and odontomas. The most frequently observed lesion in this retrospective study was KCOT (more than half of cases). Thus, this study shows that modifying the classification of the OTs altered the frequency of the lesions, possibly making KCOT the most common lesion observed in diagnostic services worldwide.

The objective of this study was to evaluate the cytological content of ameloblastomas of the jaw. Nine cases of ameloblastoma were punctured, and the intralesional material was processed using the cell block technique. After centrifugation, the pellet obtained from the punctured material was fixed in formaldehyde and routinely processed to inclusion in paraffin. The obtained sections were stained with haematoxylin and eosin (H&E). Immunohistochemical reactions against anti-pan-cytokeratin (AE1/AE3) were performed to measure the presence of epithelial cells. Cytological analyses of the obtained slides revealed the presence of epithelial cells (as evidenced by AE1/AE3 labelling) and acellular amorphous eosinophilic materials. These cytological findings, in light of clinical and imaging data, can be helpful in the presumptive diagnosis of this disease entity by eliminating other possible diagnoses. Nonetheless further studies are needed in order to determine the nature of the acellular amorphous eosinophilic material and to ascertain the immunoprofile of epithelial cells.

INTRODUÇÃO: A busca por novos métodos que auxiliem e simplifiquem de maneira eficaz o diagnóstico de lesões maxilares, cistos e tumores, objetiva beneficiar os pacientes e facilitar a atuação dos profissionais da área de diagnóstico bucal. Além dos dados clínicos, radiográficos e histopatológicos classicamente utilizados nos protocolos de investigação das lesões maxilares, a adaptação de técnicas já consagradas na medicina pode ser de grande valia. A técnica de cell block se propõe a auxiliar nesse processo, pois consiste na análise citológica de materiais, efusões e líquidos, coletados de lesões passíveis de punção aspirativa, como cistos e tumores císticos dos maxilares. OBJETIVO: Demonstrar a aplicabilidade da técnica de cell block para avaliação citológica de material biológico coletado a partir de lesões císticas dos maxilares. RESULTADOS: Das 20 lesões, das quais o conteúdo foi processado pela técnica, a avaliação citológica de cinco casos de tumores odontogênicos ceratocísticos (TOCs) demonstrou a presença predominante de ceratina, sempre com áreas de paraceratina. Nos demais casos (cinco cistos dentígeros, cinco cistos radiculares e cinco cistos residuais) foi observada a presença de hemácias, células inflamatórias e fendas de cristais de colesterol. CONCLUSÃO: A avaliação citológica, a partir da técnica de cell block, foi útil no estabelecimento do diagnóstico diferencial entre TOC e demais lesões estudadas, cistos radicular, residual e dentígero.

INTRODUCTION: The search for new methods that aid and optimize the diagnosis of cystic and tumoral maxillary lesions aims to benefit both patients and professionals from oral diagnosis. In addition to clinical, radiographic and histological findings traditionally used in research protocol for maxillary lesions, the adaptation of widely used medical techniques may be very helpful. The cell block procedure streamlines this process, inasmuch as it consists of cytopathological analysis of materials, liquids and effusions, collected from aspirated lesions such as maxillary cysts and cystic maxillary tumors. OBJECTIVE: To demonstrate the applicability of cell block technique for cytological assessment of biological material collected from cystic maxillary lesions. RESULTS: The cytological evaluation revealed that five out of 20 lesions, whose content had been processed by this technique, were odontogenic keratocystic tumors (TOCs), predominantly with keratin and always with parakeratin areas. In the other cases (five dentigerous, five radicular and five residual cysts) there were erythrocytes, inflammatory cells, and cholesterol clefts. CONCLUSION: The cytological assessment through cell block technique was useful as to establishing the differential diagnosis between TOC and other lesions, radicular, residual and dentigerous cysts.