Oral health of an indigenous population in northeastern Brazil: a cross-sectional Study of the Fulni-ô ethnic group

ABSTRACT BACKGROUND: There is a lack of studies evaluating the oral health of traditional indigenous communities in Brazil. OBJECTIVES: Thus, the objective of this study was to describe the oral health characteristics of the indigenous Fulni-ô ethnic group in Northeast Brazil. DESIGN AND SETTING: A cross-sectional observational investigation was conducted within the Project on Atherosclerosis among Indigenous Populations. METHODS: This study included participants of both sexes from the Fulni-ô ethnic group. The participants included in this investigation underwent a comprehensive oral health evaluation by a registered and experienced dentist to assess oral health and identify potentially malignant oral lesions. Participants with suspicious lesions were referred for biopsy. Shapiro-Wilk, Mann-Whitney, and Student's t-tests were used, and measures of central tendency and dispersion were described. Statistical significance was 5%. RESULTS: A total of 104 individuals were included in this study. The prevalence of the use of tobacco derivatives was 94.0%, with similarities between sexes. The prevalence of oral changes in this study population was 84.4%. Fifty-one individuals who underwent oral reassessment were referred for oral lesion biopsy. CONCLUSIONS: This study demonstrated a high prevalence of oral alterations in the Fulni-ô population. Histopathological analyses indicated the presence of mild oral epithelial dysplasia in five cases.

Elastin remodeling: Does it play a role in priming the malignant phenotype of oral mucosa?

Background: The extracellular matrix (ECM) is a dynamic tissue that provides nutrition and support to overlying epithelium. During tumorigenesis, the tumor microenvironment (TME) dysregulates the ECM. This is reflected by morphological changes seen in collagen and elastic fibers and is thought to facilitate metastasis. Aim: To study the degradation of elastic fibers in different grades of oral squamous cell carcinoma (OSCC) and in oral epithelial dysplasia (OED) using histochemistry and to correlate it to the TNM stage of OSCC. Materials and Methods: Tumor cores from 38 cases of OSCC (well-differentiated[15], moderately differentiated[14], and poorly differentiated[9]) and 15 incisional biopsies of OED were analyzed. Hematoxylin-eosin and Verhoeff's–Van Gieson (VVG) stains were used. The stained sections were assessed for morphological changes in elastic fibers. Statistical Analysis: Data were analyzed using Statistical Package for Social Sciences (SPSS) version 22 software. Fisher's exact, Kruskal–Wallis, one-way ANOVA, and Turkey post hoc tests were used to establish significance (P ? 0.05). Spearman's correlation test was used to correlate elastin fiber degradation with TNM stage of OSCC. Results: All grades of OSCC showed absence of elastic fibers around the tumor islands. Elastic fiber degradation (fragmented and clumped type fibers) increased proportionately with the grade and TNM stage of OSCC. In OED, A significant reduction in the amount of elastic fibers with increasing grade was noted. Conclusion: A positive correlation was noted between elastin degradation and grade and stage of OSCC. Therefore, it may be implicated in tumor progression of OSCC.

Immunohistochemical evaluation of E-cadherin in oral epithelial dysplasia and squamous cell carcinoma

Aim: To evaluate the expression of E-cadherin (E-cad) in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). Material and Method: Immunohistochemistry was used to detect E-cad expression in 20 cases each of normal oral mucosa, oral epithelial dysplasia and squamous cell carcinoma. Statistical Analysis Used: Inferential statistical methods for statistical analysis used were Chi-square test for comparison of the frequency between different severity of dysplasia and OSCC. Results: Upon assessing the expression of E-cad in OED and OSCC, increase in E-cad immunoreactivity was seen in early lesions. However, the expression of E-cad decreased significantly as the grade of dysplasia increased. Conclusion: We observed a significant decrease in E-cad expression from dysplasia to poorly differentiated squamous cell carcinoma suggesting that loss of expression of E-cad is closely related to carcinoma.

Epidermal Growth Factor Receptor (EGFR) is Overexpressed in Both Dysplasia and Neoplastic Oral Diseases

Introduction: The Epidermal Growth Factor Receptor (EGFR) is a transmembrane cytoplasmic protein; studies indicate that it contributes to the development and progression of potentially malignant lesions to oral squamous cell carcinoma (OSCC). In the present study we determine and characterize the expression of EGFR in samples of oral epithelial dysplasia (OED) and OSCC. Materials and Methods: 54 samples with histopathological diagnosis of OED were selected, 19 of low grade dysplasia (LGD) and 35 of high grade dysplasia (HGD) and a tissue matrix was with 60 samples of OSCC and 9 of normal oral mucosa were used. EGFR detection was performed by immunohistochemical technique. In the photomicrographs, protein expression was deter- mined. Chi square test and Fisher test were used for statistical analysis (P <0.05). Results: 54% of OED and 60% of OSCC showed a significant pattern of high EGFR expression when compared with normal oral mucosa. Discussion: We found a tendency in LGD, HGD and OSCC to over expression of EGFR. Conclusion: There is over expression of EGFR in OED and OSCC, so it could be considered as an early marker of these patholo- gies

Apoptosis in oral epithelial dysplastic lesions and oral squamous cell carcinoma: A prognostic marker.

Background: Apoptotic index (AI) using light microscopy as an indirect measure to assess the significance of apoptosis as a proliferative marker in dysplastic lesions and malignant epithelial lesions of the oral cavity. Aims: (1) To quantify the apoptotic bodies/cells in oral epithelial dysplastic (OED) lesions and oral squamous cell carcinoma (OSCC). (2) To measure AI in OED and OSCC. (3) To compare AI in OED and OSCC. Settings and Design: The proposed laboratory‑based retrospective study involved the use of hematoxylin and eosin (H and E)‑stained slides of previously diagnosed OED lesions and OSCC from institutional archives. Materials and Methods: This study constituted 50 cases, each of H and E‑stained slides of previously diagnosed cases of OED and OSCC. AI was calculated as the number of apoptotic bodies/cells expressed as a percentage of the total number of nonapoptotic tumor/dysplastic cells counted in each case. Statistical Analysis Used: Nonparametric tests such as Kruskal–Wallis test and Mann–Whitney test were used. Results: There was a statistically significant increase in AI from OED to OSCC (P = 0.000). Conclusions: Further studies need to be undertaken to detect and understand the apoptotic mechanisms in the progression from OED to OSCC.

p53 and p16 in oral epithelial dysplasia and oral squamous cell carcinoma: A study of 208 cases.

Background: The use of p16 and p53 as biomarkers of malignant transformation of oral epithelial dysplasia (OED) and biological behavior of oral squamous cell carcinoma (OSCC) is controversial. Aim: To determine the immunoexpression of p16 and p53 in OED and OSCC and to establish their possible relation to histopathological grading of OED/OSCC. Materials and Methods: Ninety‑six OEDs (40 mild, 36 moderate, and 20 severe dysplasia); and 112 OSCCs (64 well‑differentiated, 38 moderately differentiated, and 10 poorly differentiated) coming from archives of four centers of oral pathology were included. Histological slides from all cases were processed with immunohistochemical technique using anti‑p53 and anti‑p16 antibodies. The intensity of the immunoreactivity were classified using the ImageLab®MCM systemas follows: <60 mild, >60–<90 moderate, and >90 strong. Forstatistical purposesa χ2 test (P < 0.05) was performed. Results: Severe dysplasia show highest relative frequency of p16‑positive (35.5%), whereas p53 is associated with mild dysplasia (P = 0.04). Moderately differentiated OSCC had larger relative frequency of p16‑positive and p53‑positive cases (47.3% both circumstances) (P > 0.05). Statistical association of p16‑positive and p53‑positive cells to basal stratum of OED (P = 0.0008; P = 0.0000, respectively) and p16‑positive cells and p53‑positive cells to perivascular zone of OSCC (P = 0.001; P = 0.0000, respectively) was found. Conclusions: p16 and p53 could be not specific enough to identify patients suffering OED with high risk to malignancy; however, the evaluation of the presence of p16 and p53 in the tumoral invasive front of OSCC could contribute to establish the tumor progression.

Oral lichen planus: clinical profile and determination of oral epithelial dysplasia / Liquen plano oral: perfil clínico y determinación de la displasia epitelial oral

Oral lichen planus (OLP) is the most common noninfectious oral disease and is considered a potentially malignant disorders (OPMDs). The etiology and pathogenesis of OLP are not completely understood and the malignant transformation remains under discussion. The aim was to asses the cytological and histological features of OLP, and establish relationship between clinical and microscopic profiles. A total of 10 patients diagnosed with OLP were investigated. Slides were prepared and stained with Hematoxylin­Eosin to identify 8 histological features and 8 cytological alterations. Finally, oral epithelial dysplasia degree was determined. Hyperplasia and loss of polarity of basal cells were detected in 90 % of cases. Anisonucleosis, nuclear pleomorphism and hyperchromasia affected 100 % of the sample. Six cases were classified as mild-grade OED, with no cases of severe-grade. Microscopic alterations were higher in women (P <0.0001) and moderate-grade OED was diagnosed only in this group (P <0.0014). The findings demonstrated that microscopic and clinical data association should be analyzed to a better understand of disease behavior. OED was absence only in one case, so the periodic follow-up of patients diagnosed with OLP is mandatory to avoid the malignant transformation.

El liquen plano oral (LPO) es la enfermedad no infecciosa más común y se considera un trastorno potencialmente maligno. La etiología y la patogénesis del LPO no se conoce y la transformación maligna sigue siendo objeto de debate. El objetivo de este estudio fue evaluar las características citológicas e histológicas del LPO y establecer la relación entre los perfiles clínicos y microscópicos. Un total de 10 pacientes diagnosticados con LPO fueron investigados. Secciones histológicas se prepararon y tiñeron con hematoxilina-eosina para identificar 8 características histológicas y 8 alteraciones citológicas. Finalmente, se determinó el grado de displasia epitelial. La hiperplasia y la pérdida de la polaridad de las células basales se detectaron en el 90 % de los casos. Anisonucleosis, pleomorfismo nuclear e hipercromasia afectaron al 100 % de las muestras. Seis casos fueron clasificados como displasia epitelial oral (DEO) de grado leve y no se reportaron casos de grado severo. Las alteraciones microscópicas fueron mayores en las mujeres (p <0,0001) y DEO de grado moderado fue diagnosticado sólo en este grupo (p <0,0014). Los resultados demostraron que la asociación de datos microscópicos y clínicos deben ser analizados para una mejor comprensión del comportamiento de la enfermedad. La DEO estuvo ausente sólo en un caso, por lo que el seguimiento periódico de los pacientes diagnosticados con LPO es necesario para evitar la transformación maligna.

Immunohistochemical expression of Bcl‑2 in oral epithelial dysplasia and oral squamous cell carcinoma.

BACKGROUND: The B cell lymphoma‑2 gene is a proto‑oncogene whose protein product inhibits apoptosis. Its role is associated with keeping cells alive, but not by stimulating them to proliferation, as other proto‑oncogenes do. Increased expression of protein product of Bcl‑2 gene appears in the early phase of carcinogenesis leading to apoptosis impairment and in consequence to the progression of neoplastic changes. OBJECTIVE: To evaluate and compare the expression of Bcl‑2 protein in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Sixty cases of formalin‑fixed paraffin‑embedded archival specimens comprising of 30 cases of leukoplakia with oral epithelial dysplasia and 30 cases of OSCC were taken for immunohistochemical analysis using monoclonal antibody against anti‑human Bcl‑2 oncoprotein. RESULTS: Immunostaining for Bcl‑2 protein was identified in basal and parabasal layers as granular cytoplasmic staining in oral epithelial dysplasia. In OSCC, Bcl‑2 immunoreactivity was most prominent in the peripheral cells of the infiltrating tumor islands which diminished toward the center in well‑differentiated and moderately differentiated OSCC, whereas stronger and more diffuse expression of Bcl‑2 oncoprotein was seen in poorly differentiated OSCC. Overall positivity of 26.7% (8/30) was observed in oral epithelial dysplasia and 30% (9/30) in OSCC in this study. INTERPRETATION AND CONCLUSION: Altered expression of Bcl‑2 oncoprotein may be an early molecular event which leads to prolonged cell survival, increased chances of accumulation of genetic alterations, and subsequent increase in malignant transformation potential.

Estudo do perfil de expressão de componentes da via de sinalização sonic hedgehog em displasia epitelial oral / Study of the expression profile of components of sonic hedgehog signaling pathway in oral epithelial dysplasia

A displasia epitelial oral (DEO) é um aspecto histológico descrito em lesões potencialmente malignas, cujos mecanismos relacionados a patogênese e potencial de transformação são pouco conhecidos. Sabendo-se que a via de sinalização Sonic Hedgehog(SHH)tem participação no desenvolvimento do carcinoma escamocelular de boca(CEB) e que as proteínas relacionadas a esta via de sinalização estão envolvidas nos mecanismos biológicos relacionados a iniciação e progressão de tumores humanos. O objetivo deste trabalho foi estudar a expressão das proteínas da via de sinalização SHH em DEO, a fim de contribuir para o conhecimento do perfil biológico desta lesão...

Oral epithelial dysplasia (OED) is a histological aspect described in premalignant lesions and themechanisms related to the pathogenesis and malignant progression are poorly understood. It is knownthat Sonic Hedgehog (SHH) signaling pathway participates in the development of oral squamous cellcarcinoma, and proteins related to this cascade are involved in biological mechanisms related to theinitiation and progression of human tumors. The aim of this study was to investigate SHH signalingmolecules in OED, in order to contribute to the knowledge of the biological profile of this lesion...

Crystal violet stain as a selective stain for the assessment of mitotic figures in oral epithelial dysplasia and oral squamous cell carcinoma.

Background: Assessment of mitotic figures (MFs) is routinely practiced as prognostic indicator in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC), but identification of MFs poses a problem in terms of staining characteristics. Aim: To evaluate effectiveness of crystal violet stain for staining of MFs and its comparison with hematoxylin and eosin (H and E) stain. Materials and Methods: Study sample includes archival tissues embedded in paraffin blocks diagnosed as OED (n = 30) and OSCC (n = 30). The control group comprised of tissue specimen from oral mucosa of healthy volunteers (n = 30). Two serial sections of each tissue specimen were stained separately with H and E stain and 1% crystal violet stain. The stained sections were observed under microscope for identification and counting of MFs. Data obtained was statistically analyzed by using the Man-Whitney U test. Results: A significant increase in number of MFs was observed in OED and OSCC in comparison with normal oral mucosa. There was a highly significant increase in number of MFs in crystal violet stained tissue sections when compared with H and E stain. Metaphase is the most commonly observed phase of mitosis in crystal violet stain when compared with H and E stain for all three groups. Conclusion: Crystal violet stain can be considered as selective stain for mitotic figures.

Análisis clínico e histomorfológico de la mucosa oral normal, hiperplasia fibroepitelial inflamatoria oral y displasia oral / Clinical and histomorphological analysis of normal oral mucosa, oral inflammatory hyperplasia and oral epithelial displasia

El desarrollo del cáncer oral puede darse a partir de una mucosa aparentemente normal o a partir de una lesión precursora inicial, las cuales pueden representar pasos diferentes del proceso de carcinogénesis epitelial oral. El objetivo de este estudio fue analizar morfológicamente, a través de la técnica de la hematoxilina / eosina, la mucosa oral normal, con hiperplasia fibroepitelial oral y displasia epitelial oral, con el propósito de obtener mayor información sobre las alteraciones epiteliales que pueden preceder al establecimiento y evolución de una neoplasia propiamente tal. Fue observado que muchas de las alteraciones morfológicas observadas en las hiperplasias fibroepiteliales orales probablemente eran asociadas al proceso inflamatorio, donde es conocida la acción de mediadores químicos con capacidad de promover modificaciones morfológicas celulares y en la estructura tisular y no necesariamente representan alteraciones comunes de lesiones potencialmente malignas. Correlacionando el aspecto clínico de las lesiones con el diagnóstico histopatológico de displasia epitelial oral, no fue observada diferencia expresiva; sin embargo, la mayoría de los especímenes tuvo diagnostico clínico de leucoplasia. Se concluyó que la simple observación de las características morfológicas de las alteraciones de la mucosa oral puede ayudar el establecimiento del diagnóstico de las lesiones sufridas por la mucosa; sin embargo, no ofrecen muchas información sobre cuáles serían los eventos que llevarían al establecimiento de una determinada lesión.

The oral cancer development can be from apparently normal mucosa, or from precursory lesions, that can represent different step of oral epithelial carcinogenesis process. This study aimed to analyze morphologically trough the hematoxilina/eosine technique normal oral mucosa, oral fibroepithelial inflammatory hyperplasia and oral epithelial dysplasia (OED) to get more informations about the epithelial alterations that can to precede the installation and evolution of oral cancer. Its was observed that some of the morphologic alterations in the oral fibroepitelial hyperplasia were provably associated to the inflammatory process, where exist the action of chemical mediators with capacity to promote cellular morphologic modifications and alterations of the tissue architecture but not to common alterations of lesions potentially malignant. Correlating the clinical aspect of the lesions with the histopatologic diagnosis of oral epithelial dysplasia its was not observed expressive difference, however the majority of the OED specimens had clinical diagnosis of leucoplasia. Its was concluded that the simple observation of the morphologic characteristics of epithelial alterations in the oral mucosa can to improve the diagnostic of the lesions suffered by this mucosa, however, its not offers much informations about which would be the events that would lead to the establishment of a determined lesion.

Expressão imuno-histoquimico das integranas a2B1, a3B1, e a5B1, em mucosa oral norma hiperplasia fibroepitalial inflamatória oral e displasia epitelial oral

Este estudo se propôs analisar através da técnica da estreptoavidina-biotina a expressão imuno-histoquímica das integrinas α2ß1, α3ß1 e α5ß1 em 11 espécimes de mucosa oral normal (MON), 16 de hiperplasia fibroepitelial inflamatória oral (HFIO) e 25 de displasia epitelial oral (DEO) (16 leves, 2 moderadas e 7 graves), procurando determinar se existe alteração qualitativa na expressão destas integrinas e se a mesma guarda relação com as modificações sofridas pelo epitélio oral. Para a integrina α2ß1 a maioria dos espécimes exibiu uma marcação predominantemente intensa e difusa nos contatos intercelulares e no citoplasma celular das camadas basal e suprabasal, sem diferença desse perfil entre os diferentes tipos de espécimes, porém com uma tendência a fraca ou perda da expressão em 21.1% das DEOs, sendo todos os espécimes que não expressaram marcação para este heterodímero DEOs graves. Para a integrina α3ß1 a maioria da amostra exibiu uma marcação fraca ou ausente predominantemente em camada basal. A integrina α5ß1 exibiu uma forte marcação difusa nos contatos intercelulares e citoplasmática na camada suprabasal, com diferença apenas na intensidade de marcação entre os tipos de espécimes, residindo essa diferença nas DEOs, onde 12 (48%) espécimes exibiram uma fraca marcação. Concluiu-se que as integrinas avaliadas podem estar envolvidas nas interações célula-célula e célula-MEC que garantem a diferenciação celular e manutenção do arranjo estrutural tecidual. A variável expressão da integrina α5ß1 nas DEOs, poderia sugerir, respectivamente, um papel dessa molécula na sobrevida celular, com o intuito de perpetuar o fenótipo alterado nessas lesões, ou uma ação supressora desse fenótipo devido à falta de interação desta molécula com a fibronectina da MEC (AU).

The objective of this study was perform by the streptoavidin-biotin technique an immunohistochemical analysis of α2ß1, α3ß1 e α5ß1 integrins in 11 normal oral mucosa (NOM), 16 oral inflammatory fibroepithelial hyperplasia (OIFH) and 25 oral epithelial dysplasia (OED) (16 mild, 2 moderates and 7 severe), to determine if exists qualitative alteration in the expression of these integrins and if this guard relation with the oral epithelial modifications. It was observed that for the α2ß1 integrin the majority of the sample showed a predominantly intense labeling diffusely distributed in the intercellular contacts and the cytoplasm of cells of the basal and suprabasal layers, without difference of this profile between the different types of specimens, however with a trend to weak or loss of expression in 21.1% of the OEDs, being all the specimens that had not expressed this heterodimer, severe OEDs. For the α3ß1 integrin the majority of the sample showed a weak or absent labeling in basal layer. The α5ß1 integrin showed a predominant strong diffuse labeling in the intercellular contacts and cytoplasm in the suprabasal layer, with difference only in the labeling intensity between the types of specimens, inhabiting this difference in the OEDs, where 12 (48%) specimens had shown a weak labeling. It was concluded that the evaluated integrins can be involved in the cell-cell, cell-ECM interactions modulating the cellular differentiation and maintenance of the epithelial structural arrangement. The variable expression of the α5ß1 integrin in the OEDs, could suggest, respectively, a role of this molecule in the cellular survival, with intention to perpetuate the modified phenotype in these lesions, or a suppressor role on the modified phenotype due to lack of interaction of this molecule with the fibronectina of the MEC (AU).

Alterations in G1 Phase Cell Cycle Regulation during the Development of Benzo[a]pyrene-induced Epithelial Dysplasia in the Murine Tongue / Oral Science International

The environmental contaminant benzo[a]pyrene (B[a]P) has been regarded as one of the pathogens of oral premalignant and malignant lesions. To elucidate the pathogenesis of oral premalignancies, B[a]P-induced dysplasia of the murine tongue was investigated for G1-associated cell cycle regulation. B[a]P solution was applied orally up to six weeks to induce epithelial dysplasia of the tongue. BrdU incorporation and the expression of p21, cyclin D1, and CDK4 were examined by immunohistochemistry and Western blotting. Rb phosphorylation and E2F-Rb binding were examined by immunoprecipitation and Western blotting. B[a]P treatment resulted in dysplastic changes and active DNA synthesis in the tongue epithelia. Immunohistochemical analyses showed p21 up-regulation and cyclin D1/CDK4 overexpression in B[a]P-induced dysplasia. Rb hyperphosphorylation and E2F release were caused by B[a]P treatment. Thus, dysregulation of G1-phase regulation is likely to be an important event in the development of oral epithelial dysplasia in mice.