Prognostic value of the expression and localization of cell proliferation and apoptosis markers in unicystic ameloblastomas.

The aim of this study was to verify whether the expression of cell proliferation and apoptosis markers in different types of unicystic ameloblastoma (UA) is associated with the location of neoplastic cells. Immunohistochemical study with a sample of 32 cases of UA, 11 cases of conventional ameloblastoma (CAM) and ten dental follicles (DF) cases was performed. Cell proliferation was assessed using Ki-67 status, and apoptosis by caspase-3 expression. Mural UA (MUA) showed a higher immunostaining of Ki-67 (p < 0.05) and a lower immunostaining of Caspase-3 (p < 0.05) compared with luminal and intraluminal subtypes of UA and CAM. The neoplastic cells of the MUA's cystic capsule showed a higher expression of Ki-67 protein (p < 0.0001) and a lower expression of Caspase-3 (p < 0.0001) compared with the lumen. DF showed lower Ki-67 and Caspase-3 immunostaining (p < 0.05) than neoplasms. The higher immunoexpression of Ki-67 and the lower immunoexpression of Caspase-3 in MUA, in the parenchyma cells within the cystic capsule, suggest an association between the biological behaviour and location of neoplastic cells in a tumour.

Melanotic Neuroectodermal Tumor of Infancy: the Use of Immunohistochemical Analysis.

The Melanotic Neuroectodermal Tumor of Infancy (MNTI) is an asymptomatic, pigmented neoplasm characterized by a fast and locally aggressive growth along with a rare tissue formation. In the diagnostic process, the use of imaging exams can suggest a local destruction suggestive of malignancy, a sign of bone remodeling and expansion. Therefore, as any early diagnosis minimizes risks and improves the prognosis of treatment for the patient, the aim of this study was, based on a clinical case report, to corroborate the use of histopathological analysis associated with immunohistochemistry. Thus, we conclude that the immunohistochemical exam is of great importance for a better complementation of the MNTI diagnosis process. In addition, it can reveal signs of possible aggressive growth.

Ameloblastoma Differential Radiographic Findings in Children and Adolescents

ABSTRACT: The aim of this research was to investigate the radiographic, clinical, and histological features of cases of ameloblastoma from a period of 17 years in a Brazilian center and to explore potential differences in children and adolescen ts in relation to adults. Seventy-five patients diagnosed with ameloblastoma from 2001 to 2018 were included. Data from each patient including gender, age, histologic type, location, and radiographic characteristics were reviewed and analyzed retrospectively. The association between the clinical, radiographic, and histologic findings was investigated. No differences regarding the histological pattern of the lesions were observed between groups. Children and adolescents presented well- defined lesions associated with an unerupted tooth compared to adults (p<0.05). The presence of an unerupted tooth was associated with cortical erosion and expansion and MC displacement (p<0.05). Despite similar histologic characteristics, differential radiographic appearance was observed between young patients and adults.

RESUMEN: El objetivo de este trabajo fue investigar las características radiográficas, clínicas e histológicas de casos de ameloblastoma en un período de 17 años, en un centro brasileño y explorar las posibles diferencias en niños y adolescentes en relación con los adultos. Se incluyeron 75 pacientes diagnosticados con ameloblastoma desde 2001 hasta 2018. Los datos de cada paciente, incluyendo el sexo, la edad, el tipo histológico, la ubicación y las características radiográficas, se revisaron y analizaron retrospectivamente. Se investigó la asociación entre los hallazgos clínicos, radiográficos e histológicos. No se observaron diferencias en cuanto al patrón histológico de las lesiones entre los grupos. Los niños y adolescentes presentaron lesiones bien definidas asociadas a un diente no erupcionado en comparación con los adultos (p<0,05). La presencia de un diente no erupcionado se asoció con erosión y expansión cortical y desplazamiento de MC (p<0,05). A pesar de las características histológicas similares, se observó una apariencia radiográfica diferente entre pacientes jóvenes y adultos.

Conceptual changes in ameloblastoma: Suggested re-classification of a "veteran" tumor.

OBJECTIVES: The merging of ameloblastoma (AM) with mural unicystic ameloblastoma (UAM-M) was suggested by the 2017 WHO based on similar treatment needs. In an international multicenter study, we investigated the characteristics of their merged product (merged-AM) and raised the possibility of unifying AM and UAM (total-AM). MATERIALS AND METHODS: AM and UAM (luminal/intraluminal/mural), separate and combined, were analyzed for demographic/clinical/radiological features. ANOVA and chi-square tests were followed by univariate and multivariate analyses, and significance was set at p < .05. RESULTS: The patients' mean age was 39.6 ± 20.3 years in merged-AM (147 AM, 76 UAM-M), 45.1 ± 19.4 years in AM (p = .009). Merged-AM comprised 51.3% multilocular/48.7% unilocular tumors, AM comprised 72.5%/27.5%, respectively (p < .001). Merged-AM was associated with impacted teeth in 30.8%, AM in 18% (p = .023). The probability of merged-AM for multilocularity increased by 2.4% per year of age (95%CI 0.6-4.2, p = .009). Association with impacted teeth decreased by 7.9% per year of age (95%CI 1.9-14.39, p = .009). Merged-AM did not differ from total-AM (p > .05). CONCLUSIONS: Merged-AM partially differed from AM, but differences appeared to diminish in an age/time-wise manner. Merged-AM and total-AM were nearly indistinguishable. Therefore, AM and UAM may be considered a continuous spectrum of one type of tumor, further necessitating revision of the treatment approaches.

Antimicrobial resistance of bacterial strains in patients undergoing orthodontic treatment with and without fixed appliances.

OBJECTIVES: To identify microorganisms isolated from patients wearing fixed orthodontic appliances and to evaluate the resistance of isolated bacterial strains to different antimicrobials. MATERIALS AND METHODS: Seventeen healthy patients wearing a fixed orthodontic appliance (group 1) and six nonwearers (group 2, control group) were evaluated. The biofilm that formed around the orthodontic brackets was collected, and the samples were then plated in a chromogenic medium (chromIDT, bioMérieux). Colony-forming units (CFUs) were isolated and inoculated in blood-agar medium. Automated biochemical tests (VITEK 2, bioMérieux) were carried out to identify the genus and species of the microorganisms and the resistance provided by 43 drugs (37 antibacterial and 6 antifungal). RESULTS: The most prevalent microbial genera identified in group 1 were Streptococcus (24.0%), Staphylococcus (20.0%), Enterobacter (12.0%), Geobacillus (12.0%), and Candida (12.0%), and the most frequent species were Enterobacter cloacae complex (13.6%) and Staphylococcus hominis (13.6%). In group 2, the most prevalent genera were Streptococcus (57.1%), Staphylococcus (14.2%), Sphingomonas (14.2%), and Enterobacter (14.2%). With regard to antimicrobial resistance, 14 of 19 (74%) isolated bacterial strains were found to be resistant to at least 1 of the tested antimicrobials. CONCLUSIONS: The findings of the present study suggest that patients undergoing orthodontic treatment with fixed appliances have a more complex biofilm with a higher level of bacterial resistance.