Impact of radiotherapy on the morphological and compositional structure of intra-radicular dentin

Abstract Considering the side effects in the oral cavity and dental structures of radiotherapy (RDT) for head and neck cancer, this study aimed to evaluate the effects of RDT on the root dentin concerning the obliteration of dentinal tubules, the inorganic composition of intra-radicular dentin, and the integrity of collagen fibers. Thirty human canines were selected from a biobank and randomly divided into two groups (n=15). The samples were sectioned buccolingually, and a hemisection was used for structural analysis by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometer (EDS). Low-vacuum SEM images were obtained at 2000-x magnification to observe the obliteration of the dentinal tubules. Moreover, compositional evaluation was performed using EDS. After RDT, the SEM and EDS analyses were repeated using the same methodology. RDT was applied fractionally at 2 Gy per day, 5 days per week, for 7 weeks, resulting in a total dose of 70 Gy. The collagen integrity of the irradiated and non-irradiated samples was analyzed using Masson's trichrome and picrosirius red staining polarization microscopy. Samples subjected to RDT exhibited dentinal tubule obliteration (p < 0.001); low integrity of type I and III collagen fibers (p < 0.05); compositional reduction of calcium (p = 0.012), phosphorus (p = 0.001), and magnesium (p < 0.001); an increased Ca/P ratio (p < 0.001). RDT affects the structure of dentinal tubules, the inorganic composition of intra-radicular dentin, and the collagen fiber integrity in the root dentin, which may interfere with the effectiveness and durability of dental procedures.

Resumo Considerando os efeitos colaterais na cavidade oral e estruturas dentárias da radioterapia (RDT) para o câncer de cabeça e pescoço, este estudo teve como objetivo avaliar os efeitos da RDT sobre a dentina radicular quanto à obliteração dos túbulos dentinários, a composição inorgânica da dentina intra-radicular e a integridade das fibras colágenas. Trinta caninos humanos foram selecionados de um biobanco e divididos aleatoriamente em dois grupos (n=15). As amostras foram seccionadas no sentido vestíbulo-lingual, e uma hemissecção foi utilizada para análise estrutural por microscopia eletrônica de varredura (MEV) e espectrômetro de raios X de dispersão de energia (EDS). Imagens de MEV de baixo vácuo foram obtidas com aumento de 2500x para observar a obliteração dos túbulos dentinários. Além disso, a avaliação composicional foi realizada usando EDS. Após a RDT, as análises em MEV e EDS foram repetidas usando a mesma metodologia. A RDT foi aplicada fracionada a 2 Gy por dia, 5 dias por semana, durante 7 semanas, resultando em uma dose total de 70 Gy. A integridade do colágeno das amostras irradiadas e não irradiadas foi analisada usando microscopia de polarização de coloração com tricrômio de Masson e picrosirius red. As amostras submetidas a RDT apresentaram obliteração dos túbulos dentinários (p < 0,001); baixa integridade das fibras colágenas tipo I e III (p < 0,05); redução composicional de cálcio (p = 0,012), fósforo (p = 0,001) e magnésio (p < 0,001); e uma relação Ca/P aumentada (p < 0,001). A RDT afeta a estrutura dos túbulos dentinários, a composição inorgânica da dentina intra-radicular e a integridade das fibras colágenas na dentina radicular, o que pode interferir na eficácia e durabilidade dos procedimentos odontológicos.

Contribution of public oral pathology services to the diagnosis of oral and oropharyngeal cancer in Brazil

Abstract This study aimed to evaluate the contribution of oral and maxillofacial pathology laboratories (OMPLs) in Brazilian public universities to the diagnosis of lip, oral cavity, and oropharyngeal squamous cell carcinoma (SCC). A cross-sectional study was performed using biopsy records from a consortium of sixteen public OMPLs from all regions of Brazil (North, Northeast, Central-West, Southeast, and South). Clinical and demographic data of patients diagnosed with lip, oral cavity, and oropharyngeal SCC between 2010 and 2019 were collected from the patients' histopathological records. Of the 120,010 oral and maxillofacial biopsies (2010-2019), 6.9% (8,321 cases) were diagnosed as lip (0.8%, 951 cases), oral cavity (4.9%, 5,971 cases), and oropharyngeal (1.2%, 1,399 cases) SCCs. Most cases were from Brazil's Southeast (64.5%), where six of the OMPLs analyzed are located. The predominant profile of patients with lip and oral cavity SCC was Caucasian men, with a mean age over 60 years, low schooling level, and a previous history of heavy tobacco consumption. In the oropharyngeal group, the majority were non-Caucasian men, with a mean age under 60 years, had a low education level, and were former/current tobacco and alcohol users. According to data from the Brazilian National Cancer Institute, approximately 9.9% of the total lip, oral cavity, and oropharyngeal SCCs reported over the last decade in Brazil may have been diagnosed at the OMPLs included in the current study. Therefore, this data confirms the contribution of public OMPLs with respect to the important diagnostic support they provide to the oral healthcare services extended by the Brazilian Public Health System.

Decreased CD1a + and CD83 + cells in tonsillar squamous cell carcinoma regardless of HPV status

Abstract Dendritic cells (DCs) are specialized antigen-presenting cells that play a critical role in the immune response against human papillomavirus (HPV) infection, and represent a therapeutic target in cancer. Objective: To identify and quantify DCs in tonsillar squamous cell carcinoma (TSCC) under the influence of HPV infection. Methodology: CD1a and CD83 antibodies were used to identify immature dendritic cells and mature dendritic cells by immunohistochemistry in 33 primary TSCC and 10 normal tonsils (NTs), respectively. For the TSCC samples, the number of DCs per area was evaluated in the intra- and peritumoral compartments. For the NTs, the quantification of DCs was evaluated in the intra- and peritonsillar compartments. HPV detection methods were determined according to the ASCO Clinical Practice Guidelines from the College of American Pathologists Guideline (2018). Results: There were fewer intratumoral CD1a+ DCs in the HPV-positive and HPV-negative TSCC groups than in the NT group (p<0.05). In the peritumoral compartment, there were fewer CD83+ DCs in the HPV-positive and HPV-negative TSCC groups than in the NT group (p<0.001). The quantification of DCs subtypes showed no statistical differences between HPV-positive and HPV-negative TSCC groups (p>0.137). Patients with HPV-positive TSCC had significantly better overall survival rate than those with HPV-negative TSCC (p=0.004). Conclusion: Tumor activity contributes to DC depletion regardless of intralesional HPV positivity. An improved prognosis has been reported in patients with HPV-positive TSCC.

Impact of smoking on dendritic cells in patients with oral squamous cell carcinoma

Abstract Smoking has been shown to alter innate and adaptive immune responses and is directly associated with the onset of oral squamous cell carcinoma (OSCC). The purpose of this study was to evaluate the effect of cigarette smoke exposure on dendritic cells (DCs) from OSCC patients. CD1a and CD83 antibodies were used to identify immature and mature DCs, respectively, by immunohistochemistry in OSCC samples of 24 smokers and 24 non-smokers. Density of DCs was calculated in intra and peritumoral areas. Clinical and microscopic findings were reviewed and analyzed for all patients. Smokers with OSCC had a lower density of intra and peritumoral DCs when compared to non-smokers. Tumors classified as moderately/poorly differentiated had lower peritumoral CD1a+ DCs than well-differentiated tumors (p < 0.001). Smoking contributed to a depletion of immature and mature DCs in the OSCC.

Immunohistochemical expression of RANKL in oral giant cell lesions is predictive of aggressiveness

Abstract The aim of this study was to evaluate the immunohistochemical expression of receptor activator of nuclear factor kappa-B ligand (RANKL) and of osteoprotegerin (OPG), important proteins correlated with osteoclastogenesis, in central giant cell lesions (CGCL) and peripheral giant cell lesions (PGCL) and to compare their expression with the histological and clinical parameters for quantification of multinucleated giant cells (MGC) and their nuclei, lesion size, and recurrences. Twenty cases of each lesion type were selected to quantify the number of MGCs and nuclei/mm2 of connective tissue. The immunoreactivity of RANKL and OPG was expressed as a percentage of the marked area in the stroma. Clinical data were collected from pathoanatomical and medical reports. No statistical differences were found for the number of MGCs (p = 0.24) between PGCL and CGCL, but the number of nuclei within the MGCs was higher in CGCL (p = 0.01). RANKL expression was higher in CGCL than in PGCL (p = 0.04) and all recurrent lesions showed higher RANKL and OPG expressions than nonrecurrent lesions. We report higher RANKL expression and a greater number of nuclei in CGCL, which may explain the difference in clinical behaviour between these lesions and their pathogenesis.

Cellular Proliferation Index between Carcinoma Ex-Pleomorphic Adenoma and Pleomorphic Adenoma

Carcinoma ex pleomorphic adenoma (CXPA) has been considered an interesting model of carcinogenesis, presenting various histological subtypes and invasiveness phase. The objective was to determine the proliferative index of CXPA and comparing to pleomorphic adenoma (PA). Thirty six cases of CXPA (36 PA) and 22 areas of PA in CXPA (residual PA) were studied by Ki-67 expression. All CXPA cases were classified according to invasiveness phase (intracapsular, minimally and frankly invasive) and histopathological subtypes. Data was statistically analyzed by Wilcoxon, Mann-Whitney and Kruskal-Wallis tests. CXPA included 5 intracapsular, 9 minimally invasive and 22 frankly invasive cases. Fifteen cases corresponded to salivary duct carcinoma, 7 to adenocarcinoma NOS, 7 myoepithelial, 5 epithelial-myoepithelial, one case of squamous cell and one case of sarcomatoid carcinoma. The Ki-67 index of PA and residual PA were significantly lower than CXPA. Intracapsular and minimally invasive showed smaller proliferative index than frankly invasive. Considering the subtypes of CXPA, there was not a statistic difference among them. Ki-67 is a useful marker in the differential diagnosis of PA and CXPA, even when in the early invasive phase.

Carcinoma ex adenoma pleomorfo (CXAP) tem sido considerado um interessante modelo de carcinogênese, apresentando vários subtipos histológicos e fases de invasividade. Determinar o índice proliferativo de CXAP e compará-lo ao adenoma pleomorfo (AP). e seis casos de CXAP, 36 AP, e 22 áreas de AP em CXAP (AP residual) foram estudadas através da expressão de Ki-67. Todos os casos de CXAP foram classificados de acordo com a fase de invasividade (intracapsular, minimamente invasivo e francamente invasivo) e de acordo com os diversos subtipos histopatológicos. Os dados foram estatisticamente analisados através dos testes Wilcoxon, Mann-Whitney e Kruskal-Wallis. O grupo de CXAP era formado por 5 intracapsulares, 9 minimamente invasivos e 22 francamente invasivos. Quinze casos corresponderam a carcinoma de ducto salivar, 7 a adenocarcinoma nos, 7 a carcinoma mioepitelial, 5 a carcinoma epitelial-mioepitelial, 1 a carcinoma epidermoide e 1 a carcinoma sarcomatóide. Os índices de Ki-67 de AP e AP residual foram significativamente menores que o encontrado em CXAP. Os casos intracapsulares e minimamente invasivos mostraram índices proliferativos menores que os francamente invasivos. Considerando os subtipos histológicos de CXAP, não houve diferença estatística entre eles. Ki-67 é um marcador útil no diagnóstico diferencial de AP e CXAP, mesmo quando o carcinoma está em fase precoce de invasividade.

Banco de tecidos musculoesqueléticos: coleta, processamento e distribuição / Musculoskeletal tissue bank: collects, processing and distribution

Bancos de tecidos musculoesqueléticos estão disponíveis para fornecer tecidos adquiridos através de fontes pós-morte ou doadores vivos. Enxertos ósseos alógenos estão sendo utilizados de forma crescente em Implantodontia, porém poucos cirurgiões conhecem os mecanismos de obtenção desses tecidos e as técnicas de processamento. O objetivo deste trabalho é descrever os procedimentos de coleta, preparo e distribuição do osso alógeno fresco congelado.