Estrogen deficiency influences SEC23A gene expression in the odontogenic region of incisors ­ a murine model study / A deficiência de estrógeno influencia a expressão gênica de SEC23A na região odontogênica de incisivos ­ um estudo em modelo murino

Recent scientific evidence suggests a close relationship between estrogen deficiency and vitamin D- related genes. Estrogen and vitamin D were involved with alterations in odontogenesis and tooth eruption process. Objective: The aim of the present study was to evaluate the influence of estrogen deficiency on the expression of genes related to the activation and degradation of vitamin D in the odontogenic region of incisors in a murine model. Material and Methods: This is an experimental clinical study that used female Wistar Hannover rats. The animals were randomly divided into two groups according to the intervention received: Hypoestrogenism Group ­ animals submitted to estrogen deficiency by ovariectomy surgery and Control Group ­ animals submitted to sham surgery. Surgical intervention was performed in the prepubertal period; the animals were followed throughout the pubertal period. After euthanasia, the hemimandibles were removed to evaluate the mRNA expression of the vitamin D-related genes AMDHD1, CYP24A1, NADSYN1 and SEC23A in the odontogenic region of incisors through real time PCR. Student's t test was used to compare means. Kruskal-Wallis test and Dunn's posttest were also used. The level of significance was 5%. Results: SEC23A was overexpressed in the estrogen deficiency condition in the odontogenic region (p=0.021). Conclusion: Estrogen deficiency may influence the expression of the SEC23A gene involved in the activation and degradation of vitamin D in the odontogenic region of incisors in a murine model(AU)

Evidências científicas recentes sugerem uma estreita relação entre a deficiência de estrógeno e os genes relacionados à vitamina D. O estrógeno e a vitamina D estão envolvidos com alterações na odontogênese e no processo de erupção dentária. Objetivo: O objetivo do presente estudo foi avaliar a influência da deficiência de estrógeno na expressão de genes relacionados à ativação e degradação da vitamina D na região odontogênica de incisivos em modelo murino. Material e Métodos: Trata-se de um estudo clínico experimental que utilizou ratas Wistar Hannover fêmeas. Os animais foram divididos aleatoriamente em dois grupos de acordo com a intervenção recebida: Grupo Hipoestrogenismo ­ animais submetidos à deficiência de estrógeno pela cirurgia de ovariectomia e Grupo Controle ­ animais submetidos à cirurgia simulada. A intervenção cirúrgica foi realizada no período pré-púbere; os animais foram acompanhados durante todo o período puberal. Após a eutanásia, as hemimandíbulas foram removidas para avaliar a expressão de mRNA dos genes AMDHD1, CYP24A1, NADSYN1 e SEC23A, relacionados à vitamina D, na região odontogênica de incisivos por meio de PCR em tempo real. O teste t de Student foi utilizado para comparar as médias. Também foram utilizados o teste de Kruskal-Wallis e o pós-teste de Dunn. O nível de significância foi de 5%. Resultados: SEC23A foi superexpresso na condição de deficiência de estrógeno na região odontogênica (p=0,021). Conclusão: A deficiência de estrógeno pode influenciar a expressão do gene SEC23A envolvido na ativação e degradação da vitamina D na região odontogênica de incisivos em modelo murino (AU)

Investigating the association between dental age and polymorphisms in genes encoding estrogen receptors

Abstract Background Genetic polymorphisms have been shown to influence several physiological traits, including dental and craniofacial characteristics. Understanding the clinical relevance of genetic polymorphisms in dental practice is crucial to personalize treatment plans and improve treatment outcomes. Objective to evaluate the association between dental age and genetic polymorphisms in genes encoding estrogen receptors alpha and beta (ESR1 and ESR2, respectively) in a sample of Brazilian children. Methodology This retrospective cross-sectional study was performed with children undergoing orthodontic treatment. Patients with syndromes, congenital anomalies, craniofacial deformities, under hormonal or systemic treatment, and with a previous history of facial trauma were excluded. Panoramic radiographs were used to assess dental age according to the Demirjian, Goldstein, and Tanner method. A delta [dental age-chronological age (DA-CA)] was obtained, which shows whether the patient tends to have a normal, delayed (negative values), or advanced (positive values) dental age. DNA isolated from buccal cells was used to genotype four genetic polymorphisms: rs9340799 (A>G) and rs2234693 (C>T), located in ESR1; and rs1256049 (C>T) and rs4986938 (C>T), located in ESR2. A statistical analysis was performed and values of p<0.05 indicated statistical difference. Results A total of 79 patients were included, 44 (55.70%) girls and 35 (44.30%) boys. The Demirjian, Goldstein, and Tanner method, in general, overestimated patients' age by 0.75 years. There was no difference in the delta of dental age between the sexes (p>0.05). Genetic polymorphisms in ESR1 and ESR2 were not associated with dental age (p>0.05). Conclusion The studied genetic polymorphisms in ESR1 and ESR2 were not associated with dental age in Brazilian children.

Higher immunoexpression of CK14 from the Wnt-1/β-catenin pathway in the development of odontomas

Abstract Tooth development depends on a series of reciprocal signaling interactions between the oral epithelium and ectomesenchyme. This study aimed to investigate the role of CK14, a protein involved in Wnt-1/β-catenin signaling, in odontogenesis and the development of odontomas. This cross-sectional, retrospective, immunohistochemical study analyzed 30 compound odontomas, 30 complex odontomas, and 17 tooth germs. Higher immunoexpression of CK14 was observed in odontogenic epithelial cells of tooth germs (p < 0.001) and odontogenic epithelial cells of odontomas (p < 0.001). There was higher immunoexpression of Wnt-1 and β-catenin proteins in epithelial cells of tooth germs (p = 0.002 and p < 0.001, respectively), as well as in the ectomesenchyme of odontomas (p = 0.003 and p < 0.001, respectively). β-Catenin was moderately and significantly correlated with CK14 in the membrane of reduced enamel epithelial cells in odontomas (p = 0.007). Higher immunoexpression of CK14 was observed in the odontogenic epithelium during the bud and cap stages and lower immunoexpression in the internal enamel epithelium during the bell stage. In odontomas, lower expression of Wnt-1/β-catenin and higher immunoexpression of CK14 were found in odontogenic epithelial cells, especially adjacent to the mineralized material resembling the tooth formed in these lesions.

Resumo O desenvolvimento dentário depende de uma série de interações de sinalização recíproca entre o epitélio oral e o ectomesênquima. O objetivo deste estudo foi investigar o papel da CK14 das vias WNT-1/β-catenina na odontogênese e no desenvolvimento de odontomas. Este estudo transversal, retrospectivo, imuno-histoquímico analisou 30 odontomas compostos, 30 odontomas complexos e 17 germes dentários. A CK14 apresentou maior imunoexpressão em células epiteliais odontogênicas de germes dentários (p<0,001) e em células epiteliais odontogênicas de odontomas (p<0,001). A Wnt-1 e a β-catenina apresentaram maior imunoexpressão de proteínas nas células epiteliais dos germes dentários (p = 0,002 e p<0,001, respectivamente), bem como no ectomesênquima dos odontomas (p = 0,003 e p < 0,001, respectivamente). A β-catenina correlacionou-se moderada e significativamente com a CK14 na membrana de células epiteliais reduzidas do esmalte em odontomas (p = 0,007). Maior imunoexpressão da CK14 foi observada no epitélio odontogênico nos estágios de botão e capuz com menor imunoexpressão no epitélio interno do órgão do esmalte no estágio de sino. Nos odontomas, foi observado menor expressão de Wnt-1/β-catenina e maior imunoexpressão da CK14 presente nas células epiteliais odontogênicas, especialmente, vizinhas ao material mineralizado semelhante ao dente formado nessas lesões.

O papel de proteínas das vias WNT/ß-Catenina, TGF-ß/BMP4 e SHH na odontogênese e odontomas / The role of proteins from the WNT/ß-Catenin, TGF-ß/BMP4 and SHH pathways in odontogenesis and odontomas

O desenvolvimento do dente depende de uma série de interações sinalizadoras recíprocas entre o epitélio oral (EO) e o ectomesênquima derivado da crista neural, a via WNT com o TGF-ß e BMP4 tem sido implicada na tumorigênese. A via de sinalização tipo Wingless (Wnt) / ß-catenina é essencial para a ativação precoce da odontogênese e no desenvolvimento de tumores odontogênicos. O TGF-ß e as BMPs tem sido associadas aos processos de dentinogênese reacionária e reparadora. A sinalização de Shh pode regular a proliferação celular no ectomesênquima dentário, controlando assim a morfogênese dentária. O objetivo da pesquisa foi investigar a atuação de algumas proteínas das vias na odontogênese e na formação de odontomas e tumores odontogênicos mistos benignos, para isto, foi desenvolvido um estudo seccional restrospectivo e imuno-histoquímico contendo 23 odontomas compostos, 21 odontomas complexos, 17 germes dentários, 05 fibro-odontomas ameloblásticos e 01 fibroma ameloblástico. Os resultados encontrados demonstraram maiores imunoexpressões da via WNT/ß-catenina no epitélio dos germes dentários (p<0,001) e no fibroma ameloblástico, enquanto que, esteve no ectomesênquima dos odontomas (p<0,001) e fibro-odontomas ameloblásticos. A via WNT/ßcatenina correlacionou-se moderadamente e significativamente com a CK14 no epitélio (p = 0,007) dos odontomas. A BMP4 foi imunoexpressa, especialmente, no ectomesênquima dos odontomas complexos (mediana = 33,7; p<0,001). A via Shh foi mais imunoexpressa no epitélio dos germes dentários (p<0,001) e no ectomesênquima dos odontomas complexos (p=0,029). De forma similar, o TGFß apresentou maior imunoexpressão no epitélio dos germes dentários (p<0,001) e no ectomesênquima dos odontomas complexos (p = 0,002). O dente em desenvolvimento exibiu maiores concentrações para estas proteínas no epitélio odontogênico nas fases de botão e capuz e a expressão diferencial ocorreu, principalmente, no ectomesênquima dos tumores, o que indica que esse componente é de fato mais proliferativo (AU).

Tooth development depends on a series of reciprocal signaling interactions between oral epithelium (EO) and neural crest-derived ectomesenchyme, the WNT pathway with TGF-ß and BMP4 has been implicated in tumorigenesis. The Wingless (Wnt)/ß-catenin signaling pathway is essential for the early activation of odontogenesis and the development of odontogenic tumors. TGF-ß and BMPs have been associated with reactionary and reparative dentinogenesis processes. Shh signaling can regulate cell proliferation in dental ectomesenchyme, thus controlling dental morphogenesis. The objective of the research was to investigate the role of some proteins in the pathways in odontogenesis and in the formation of odontomas and benign mixed odontogenic tumors. tooth germs, 05 ameloblastic fibro-odontomas and 01 ameloblastic fibroma. The results found showed higher immunoexpressions of the WNT/ß-catenin pathway in the epithelium of tooth germs (p<0.001) and in ameloblastic fibroma, while it was in the ectomesenchyme of odontomas (p<0.001) and ameloblastic fibroodontomas. The WNT/ß-catenin pathway correlated moderately and significantly with CK14 in the epithelium (p = 0.007) of odontomas. BMP4 was immunoexpressed, especially in the ectomesenchyme of complex odontomas (median = 33.7; p<0.001). The Shh pathway was more immunoexpressed in the epithelium of tooth germs (p<0.001) and in the ectomesenchyme of complex odontomas (p=0.029). Similarly, TGF-ß showed higher immunoexpression in the epithelium of tooth germs (p<0.001) and in the ectomesenchyme of complex odontomas (p = 0.002). The developing tooth exhibited higher concentrations of these proteins in the odontogenic epithelium in the bud and cap phases and the differential expression occurred mainly in the ectomesenchyme of the tumors, which indicates that this component is in fact more proliferative (AU).

Expression of the of STRO-1 and HSP-25 markers during odontogenesis / Expressão dos marcadores STRO-1 e HSP-25 durante a odontogênese

ABSTRACT Objective: Therefore, the purpose of the currently study was to analyze the expression of the STRO-1 stem cell marker and the marker related to Hsp25 differentiation and dental development during odontogenesis in rats. Methods: Eighteen-day Wistar rat embryos and 7-day-old animals were analyzed morphologically via Hematoxylin and Eosin (HE) staining and via immunohistochemical marking for Stro-1 and Hsp25 in 5uM serial sections. Results: In the HE morphological analysis in 18-day embryos, the stage of tooth development was in the cap phase, while in the 7-day old animals it was in the bell phase. Conclusion: The expression of STRO-1 in the embryos was not found in the region of the dental papilla or enamel organ, however, in the 7-day-old animals, STRO-1-positive cells were found in the region of the dental follicle and dental papilla. As for the Hsp25, this exhibited weak marking in the cap phase while in the bell phase, there was a reaction, mainly in the odontoblasts. The expressions in the site of these markers vary according to the stage of tooth development.

RESUMO Objetivo: Analisar a expressão do marcador de células-tronco STRO-1 e o marcador relacionado à diferenciação da Hsp25 e ao desenvolvimento dental durante a odontogênese em ratos. Métodos: Embriões de ratos Wistar de dezoito dias e animais de sete dias de idade foram analisados morfologicamente através da coloração com Hematoxilina e Eosina (HE) e através de marcação imuno-histoquímica para STRO-1 e Hsp25 em seções seriais de 5uM. Resultados: Na análise morfológica da HE em embriões de 18 dias, o estágio de desenvolvimento dos dentes estava na fase capuz, enquanto nos animais de 7 dias estava na fase de campânula. Conclusão: Nos embriões, a expressão de STRO-1 não foi encontrada na região da papila dentária ou no órgão do esmalte; no entanto, nos animais de sete dias de idade, células positivas para STRO-1 estava presente na região do folículo e papila dentária. Quanto ao Hsp25, este apresentou fraca marcação na fase capuz, enquanto na fase campânula houve reação, principalmente nos odontoblastos. As expressões no local desses marcadores variam de acordo com o estágio do desenvolvimento dentário.

Temporo-spatial distribution of stem cell markers CD146 and p75NTR during odontogenesis in mice

Abstract Mesenchymal and epithelial stem cells were identified in dental tissues; however, knowledge about the odontogenic stem cells is limited, and there are some questions regarding their temporo-spatial dynamics in tooth development. Objective Our study aimed to analyze the expression of the stem cell markers CD146 and p75NTR during the different stages of odontogenesis. Methodology The groups consisted of 13.5, 15.5, 17.5 days old embryos, and 14 days postnatal BALB/c mice. The expression of CD146 and p75NTR was evaluated by immunohistochemistry. Results Our results showed that positive cells for both markers were present in all stages of tooth development, and the number of positive cells increased with the progression of this process. Cells of epithelial and ectomesenchymal origin were positive for CD146, and the expression of p75NTR was mainly detected in the dental papilla and dental follicle. In the postnatal group, dental pulp cells were positive for CD146, and the reduced enamel epithelium and the oral mucosa epithelium showed immunostaining for p75NTR. Conclusions These results suggest that the staining pattern of CD146 and p75NTR underwent temporal and spatial changes during odontogenesis and both markers were expressed by epithelial and mesenchymal cell types, which is relevant due to the significance of the epithelial-ectomesenchymal interactions in tooth development.

COVID-19 Pandemic: Oral Repercussions and its Possible Impact on Oral Health

Abstract Many viral infections cause oral manifestations, including disorders in odontogenesis, resulting in dental malformations. In this review, based on current knowledge, we will discuss the likely dental and oral consequences of COVID-19. In this article, we review currently available data associated with vertical transmission of COVID-19 and odontogenesis, oral manifestations, and the impact of COVID-19 pandemic on a diagnosis of oral diseases. Owing to the severity of the pandemic, the population's anxiety and fear of becoming infected with COVID-19 may underestimate the signs and symptoms of serious illnesses, besides discourage patients from seeking health, medical or dental services to determine the diagnosis of oral lesions. Thus, the COVID-19 pandemic could be an additional and aggravating factor for the delay of serious illness diagnosis, such as oral squamous cell carcinoma resulting in higher morbidity and worse prognosis. Several changes and oral lesions have been described as oral manifestations of COVID-19, such as dysgeusia, oral ulcers, petechiae, reddish macules, desquamative gingivitis, among others. Besides, it can cause major systemic changes and predispose opportunistic infections. As with other viral infections, oral manifestations, including dental anomalies, can occur as a direct result of SARS-CoV-2 infection. However, further studies are needed to guide and clarify possible oral changes.

Research progress on the distribution of primary cilia and related signaling pathways involved in odontogenesis / 口腔疾病防治

@#Primary cilia are organelles present on most mammalian cells that sense environmental changes and transduce signaling, and they are the key coordinators of various signaling pathways during tissue development. This article reviews the progress of research on the distribution of primary cilia in tooth development and the related signaling pathways. A literature review shows that in odontogenesis, primary cilia play an important role in the mutual induction of the epithelium and mesenchyme; during the continuous proliferation and differentiation of cells, the distribution of primary cilia is temporally and spatially dependent. Although the reason for this distribution is still unclear, some experimental evidence indicates that this phenomenon is compatible with the function of cells and tissues in which primary cilia are distributed. Primary cilia are involved in the regulation of two important signaling pathways, Hedgehog and Wnt, in odontogenesis. Genes encoding cilia (such as Kif3a, Evc/Evc2 and Ift) can affect the development of teeth by regulating these two signaling pathways, and there is an interaction between the two signaling pathways. Deletion of related genes (such as Ofd1 and Bbs) can damage the transmission of upstream and downstream signals by damaging the structure or function of cilia, thereby causing various types of dental dysplasia, including small teeth, enamel hypoplasia, missing teeth, or craniofacial deformities.

Desenvolvimento do sistema estomatognático durante a vida intrauterina: revisão de literatura / Development of the stomatognathic system during the intrauterine life: literature review

Através de uma Revisão da Literatura, o trabalho busca consolidar informações sobre o desenvolvimento do sistema estomatognático, durante a vida intrauterina. Foram realizadas pesquisas sobre o tema abordado, nas seguintes bases de dados: Scielo, Medline; Bireme; Google Acadêmico e o PubMed, no intervalo de tempo de agosto de 2006 a junho de 2017. Livros publicados no mesmo período também foram consultados. Foram selecionados os artigos em português ou inglês, que contemplaram assuntos inerentes ao estudo. O desenvolvimento do sistema estomatognático acontece a partir do primeiro mês gestacional. A exposição materna a fatores de risco como infecções, traumatismos, desnutrição e consumo de drogas, pode deixar sequelas no feto, comprometendo estruturas e funções buco-dentais.

Through a Literature Review, this work aims to consolidate information about the development of the stomatognathic system during the intrauterine life. The development of the stomatognathic system happens from the first gestational month. Maternal exposure to risk factors, such as infections, trauma, malnutrition, drug use, may leave sequels in the fetus and may compromise buccal-dental structures and functions.

Unveiling The Role Of Shh From Embryogenesis To Its Reactivation In Tumorigenesis:A Maxillofacial Perspective.

Sonic Hedgehog gene (SHH) plays a vital role in embryogenesis through its secreted protein sonic hedgehog protein (Shh). During embryogenesis, Shh acts as a morphogen controlling proximal and distant signaling in the specific development of tissue lineages, patterning, regulation of cell proliferation and suppression of tissue apoptosis. Shh also exerts its role in odontogenesis by determining the site of tooth bud formation, in tooth morphogenesis and root formation. The difference in the specific development of a region by Shh can be explained by its [a] 'Spatial gradient [b] the 'form' [c] Concentration gradient and [d] Temporal gradient. Shh signaling pathway has an extracellular and an intracellular component. A disruption of Shh pathway contributes to tumorigenesis of several cell types including those arising from odontogenic structures. This article reviews Shh from its formation in embryonic stages, its role in development and odontogenesis, to its reactivation in tumorigenesis and in specific to odontogenic pathologies.

Explanation for the signs and symptoms of tooth eruption: mast cells

Abstract This study contributes to the understanding of the mechanisms associated with signs and symptoms of tooth eruption, by investigating the presence of mast cells in pericoronal tissues during the intraosseous (Group 1) and submucosal (Group 2) phases of eruption. We compared findings for these two groups with each other and with those for the oral mucosa (Group 3). In each group, 14 specimens were analyzed microscopically after hematoxylin and eosin staining and immunohistochemical analysis of c-Kit and tryptase expression. Results revealed that the number and density of mast cells is different in follicular tissues according to the eruption phase, which may mean that: 1) masticatory trauma of the oral mucosa and dental follicles in the submucosa may explain why reduced enamel epithelium exposes enamel to the cells of the connective tissue; 2) exposure of antigenic enamel proteins might correspond to the release of sequestered antigens, which may lead to the interaction of IgE and a greater number of mast cells in the region; and 3) the consequent degranulation and the local release of mediators, such as histamine, leukotrienes, prostaglandins, proteases, cytokines and growth factors, contribute to the understanding of signs and symptoms associated with tooth eruption.

Resumo Para contribuir com a compreensão dos mecanismos relacionados à sintomatologia e aos sinais associados à erupção dentária, investigou-se a presença de mastócitos nos tecidos pericoronários na fase intraóssea (Grupo 1) e submucosa (Grupo 2), comparando-os entre si e com a mucosa bucal (Grupo 3). Em cada grupo, 14 espécimes foram analisados microscopicamente em cortes corados com hematoxilina e eosina, e imunocitoquimicamente marcados com Ckit e Triptase. Pelos resultados obtidos, concluiu-se que a quantidade/densidade dos mastócitos é diferente nos tecidos foliculares de acordo com a fase de erupção, o que permite inferir que: 1) O traumatismo decorrente da mastigação sobre o conjunto "mucosa bucal com o folículo pericoronário na submucosa" pode explicar porque o epitélio reduzido exporia o esmalte às células do tecido conjuntivo; 2) A exposição das proteínas do esmalte com propriedades antigênicas corresponderia à liberação de antígenos sequestrados que levariam à interação de IgE e mastócitos em número aumentado na região; e 3) A consequente degranulação e liberação de mediadores no local, como histamina, leucotrienes, prostaglandinas, proteases, citocinas e fatores de crescimento, contribuem para a compreensão dos sinais e sintomatologia atribuídos à erupção dentária.

Matrix Metalloproteinase 2: A Possible Role inTooth Development and Eruption / Metaloproteinasa de matriz 2: Un posible papel en el desarrollo dental y la erupción

Abstract 18. Introduction: Tooth development results from a highly coordinated epithelial-mesenchyme interaction in which mesenchyme cells originate the dental papilla and dental follicle, while ectodermal cells originate the enamel organ. Simultaneously, bone tissue is formed around the developing tooth, trapping it in a bony crypt. Tooth eruption requires the resorption of the coronal part of the bony crypt, followed by degradation of the lamina propria, most likely by metalloproteinases (MMPs) activity. Objectives: The aim of this research was to determine MMP-2 expression in the dental germ cells (ameloblasts, odontoblasts, dental papilla and dental follicle) and surrounding tissues (alveolar bone and lamina propria) of rat molars throughout the eruptive process. Material and Methods: A total of 24 rats (4,6,9,11,14 and 16 days old) were used in this study. MMP-2 was detected through immunohistochemistry. A qualitative analysis was performed to investigate the expression of MMP2 in the dental germ cells, lamina propria, and coronal and basal regions of the bony crypt. Results: MMP-2 expression was observed in the dental papilla cells, dental follicle, ameloblasts, odontoblasts and bone cells from the coronal and basal regions of the bony crypt. MMP-2 was also detected in the lamina propria during the mucosal penetration stage of tooth eruption. Conclusion: We conclude that MMP-2 may be important for the extracellular matrix rearrangement necessary for tooth development and secretion of its mineralized tissues. We also conclude that MMP-2 may play a role in the extensive tissue remodeling during the intra-and-extra-osseous phases of the tooth eruption process.

Resumen 24. Introducción: el desarrollo del diente resulta de una interacción epitelial-mesénquima altamente coordinada en la cual las células mesénquima originan la papila dental y el folículo dental, mientras que las células ectodérmicas originan el órgano del esmalte. Simultáneamente, el tejido óseo se forma alrededor del diente en desarrollo y lo atrapa en una cripta ósea. La erupción dentaria requiere la resorción de la parte coronal de la cripta ósea, seguida de la degradación de la lámina propia, muy probablemente por la actividad metaloproteinasas (MMPs). Objetivos: el objetivo de esta investigación fue determinar la expresión de MMP-2 en las células germinales dentales (ameloblastos, odontoblastos, papila dentaria y folículo dentario) y tejidos circundantes (hueso alveolar y lámina propia) de molares de rata a lo largo del proceso eruptivo. Material y métodos: en este estudio se utilizó un total de 24 ratas (4,6,9,11,14 y 16 días de edad). MMP-2 se detectó a través de inmunohistoquímica. Un análisis cualitativo fue realizado para investigar la expresión de MMP-2 en las células de germen dentales, el lámina propria, y las regiones coronales y basales de la cripta ósea. Resultados: la expresión de MMP2 fue observada en las células de la papila dental, el folículo dental, el ameloblastos, el odontoblastos y las células del las regiones basales y coronales de la cripta ósea. La expresión de MMP-2 también se detectó en la lámina propia durante la etapa de penetración de la mucosa de la erupción dental. Conclusión: Concluimos que MMP-2 puede ser importante para el cambio extracelular de la matriz necesario para el desarrollo del diente y la secreción de sus tejidos mineralizados. También concluimos que MMP-2 puede desempeñar un papel en la remodelación extensa del tejido durante las fases intra y extraósea del proceso de erupción dental.

Fisiopatología de los odontoblastos: una revisión / Odontoblast pathophysiology: a review

Los odontoblastos son células posmitóticas de origen mesenquimal dispuestas en forma de palizada en la periferia de la pulpa dental y responsables de la formación de la dentina. Los odontoblastos derivan de la cresta neural,y su diferenciación es la consecuencia de las interacciones epitelio-mesénquima entre las células de la papila dental y el epitelio dental interno. Este trabajo tiene como objetivo revisar los aspectos fisiológicos y patológicos de los odontoblastos, comprendiendo su origen, mecanismos de diferenciación y propiedades funcionales. Se realizó una búsqueda electrónica de literatura desde el año 2000 hasta febrero de 2018y seseleccionaron 2.889 artículos, de los cuales 52 fueron analizados y discutidos. Los resultados exponen el origen, las etapas y los factores relacionados con la diferenciación odontoblástica, junto con los aspectos principales de la organización estructural y las funciones que desempeñan los odontoblastos. Esta revisión demuestra mediante la evidencia científica actual cómo los estudios concernientes a los odontoblastos se focalizan en comprender los mecanismos en la formación de la dentina reparativa, la respuesta inmunitaria y su rol en los procesos de inflamación y dolor. Trabajos futuros deberán esclarecer las diferentes señales involucradas en los procesos fisiopatológicos celulares y moleculares llevados a cabo por los odontoblastos.

The odontoblasts are post-mitotic cells of mesenchymal origin arranged in the form of a palisade in the periphery of the dental pulp and responsible for the formation of the dentin. The odontoblasts are derived from the neural crest and their differentiation is the consequence of epithelial-mesenchymal interactions between the cells of the dental papilla and the internal dental epithelium. This work aims to review the physiological and pathological aspects of odontoblasts, including their origin, mechanismsof differentiation and functional properties. An electronic literature search was conducted from 2000 to February 2018, selecting 2889articles, of which 52 articles were analyzed and discussed. The results show the origin, stages and factors related to odontoblastic differentiation, together with the main aspects of the structural organization and functions performed by odontoblasts. This review demonstrates through current scientific evidence that the studies concerning odontoblasts focus on understanding the mechanisms in the formation of reparative dentin, the immune response and its role in the processes of inflammation and pain. Future work should clarify the different signals involved in the cellular and molecular pathophysiological processes carriedout by the odontoblasts.

The role of bone morphogenetic protein signaling pathway in tooth root development / 华西口腔医学杂志

The bone morphogenetic protein (BMP) family is an important factor in the regulation of cell ular life activities and in the development of almost all tissues. BMP-mediated signaling plays an important role in tooth root development, which is a part of tooth development. Epithelial and mesenchymal interactions are involved in tooth root development, but the BMP signaling pathway has a different effect on tooth root development in epithelial and mesenchymal. This review summarizes the advances of BMP signaling in tooth root development.

Clinical Risk Factors Influencing Dental Developmental Disturbances in Childhood Cancer Survivors / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Although studies regarding dental developmental disturbances after childhood cancer treatment have increased, they have many limitations. Studies analyzing the significance of independent clinical risk factors with regard to the dental health status are also rare. We aimed to investigate the risk factors for dental developmental disturbances, particularly severe disturbances, in childhood cancer survivors (CCS). MATERIALS AND METHODS: Oral examinations and retrospective reviews of medical and panoramic radiographs were performed for 196 CCS (mean age, 15.6 years). Cancer type, age at diagnosis, treatment modality, type and accumulated dose of administered drugs, and dose and site of radiation were recorded. Dental developmental disturbances were diagnosed using panoramic radiographs and graded for severity according to the Modified Dental Defect Index (MDDI). Descriptive statistics and multivariate analyseswere performed to determine the association between dental abnormalities and clinical factors. RESULTS: In total, 109 CCS (55.6%) exhibited at least one dental anomaly, and the median value of MDDI was 2.5. Microdontia (30.6%) was the most prevalent anomaly, followed by tooth agenesis (20.4%), V-shaped roots (14.8%), and taurodontism (10.2%). Multivariate analysis revealed that a young age at diagnosis (≤ 3 years), a history of hematopoietic stem cell transplantation, the use of multiple classes of chemotherapeutic agents (≥ 4 classes), and the use of heavy metal agents were significant risk factors for severe dental disturbances. CONCLUSION: CCS with any of the above risk factors for severe developmental disturbances should be comprehensively followed up to minimize adverse consequences to their dental development and preserve their future dental health.

Dientes fuera de la cavidad oral, un hallazgo infrecuente / Teeth outside the oral cavity, an uncommon finding

Los dientes derivan de tres estructuras embriológicas importantes: las células de la cresta neural, el mesodermo y el ectodermo bucal. Asimismo, los teratomas son lesiones tumorales que se desarrollan a partir de las células germinales de las tres capas germinativas embrionarias y que pueden dar lugar a la formación de estructuras dentales, adiposas, pilosas, óseas, cartilaginosas en localizaciones anatómicas aberrantes pudiendo aparecer en los pulmones, los ovarios, los testículos, la región hipofisiaria y pineal. Se trata de lesiones generalmente asintomáticas y subclínicas que tienden a aparecer en las primeras tres décadas de la vida y son comúnmente diagnosticadas de forma accidental mediante estudios imagenológicos como la tomografía axial computarizada o la resonancia magnética. Se describe el caso de una paciente de 28 años a quien se le realizó la extirpación de una masa tumoral en el ovario con el diagnóstico presuntivo de teratoma, y al realizar su apertura se encontraron órganos dentarios en su interior. El objetivo principal de este artículo es explicar el proceso embrionario que da lugar a losdientes y las circunstancias patológicas que pueden ocasionar que esteproceso odontogénico se suscite en sitios anatómicos aberrantes yatípicos ajenos a la cavidad bucal.

Teeth are derived from three important embryological structures: the neural crest cells, oral mesoderm and ectoderm. Also, teratomas aretumoral lesions that are developed from the germ cells of the threeembryonic germinative layers and that can give rise to the formation of dental, adipose, hairy, bony, cartilaginous structures in aberrant anatomical locations that can appear in lungs, ovaries, testicles, pituitary and pineal region. These are usually asymptomatic and subclinical lesions that tend to appear in the first three decades of lifeand are commonly diagnosed accidentally by imaging studies such ascomputed tomograph or magnetic resonance imaging. We describe thecase of a 28-year-old patient who was removed from a tumor mass in theovary with a presumptive diagnosis of teratoma and when they openedit, dental organs were found inside. The main objective of this articleis to explain the embryonic process that gives rise to the teeth and thepathological circumstances that can cause this odontogenic process toarise in anatomical aberrant and atypical sites outside the oral cavity.

Effect of maternal health and prenatal environmental exposure factors on tooth development / 华西口腔医学杂志

Odontogenesis is a consequence of a complex series of reciprocal signal interactions between odontogenic epithelium and neural crest-derived odontotgenic mesenchyme. These interactions result from a complex interplay of genetic and environmental factors. Given that a fetus develops in the mother, maternal health and environmental exposures have a great influence on tooth development. In this review, we focused on the key issues in the developmental defects of teeth induced by various types of maternal environmental factors, including environmental endocrine disruptors, joint action of two or more chemical exposures, and maternal health status. This review also discussed the adverse effects of maternal environmental factors on tooth development. These effects include enamel developmental defects, molar incisor hypomineralization, dental fluorosis, hyperdontia and hypodontia. Overall, this review provides a theoretical basis for the prevention of tooth defects in early life, assessment of risks from developmental tooth defects, and advancement of pediatric oral health management.

Establishment of first mandibular molar development of the time sequence in ICR mice / 中国比较医学杂志

Objective This study aims to understand the characteristics of the time sequence of ICR mouse first mandibular molar tooth germ development through dynamic observation.Methods Tooth germ of Embryos (E11.5,E12.5,E13.5,E14.5,E15.5,E16.5,E17.5 and E18.5) and postnatal (PN1,PN2) mice were obtained.The heads (E11.5-E15.5) and mandibles (E16.5-PN2) of mice were dissected,fixed and embedded for serial sections and HE staining.All the results were assessed under light microscopy.Results The tooth germ underwent various development stages including the bud,cap and bell stages.Mouse odontogenesis was initiated at E11.5.Proliferation of oral epithelium formed the bud stage at E13.5.Then the cap stage was observed at E14.5-E15.5 and the bell stage was appeared beginning from E16.5.The pre-dentin was observed at PN1,as well as the dentin at PN2.Conclusions Establishing the regular development pattern of the first mandibular molar of ICR mice will provide a reliable basis for the future use in the specific tooth germ developmental research.

Perfil clínico e histopatológico do cisto odontogênico calcificante: relato de caso / Clinical and histopathological features of calcifying odontogenic cyst: case report

O cisto odontogênico calcificante (COC) é considerado como condição patológica benigna de ocorrência rara em maxila e mandíbula, caracterizado por revestimento cístico de células epiteliais odontogênicas, contendo células fantasmas com propensão a regiões de calcificação. Neste artigo, descreveu-se a configuração clínica e histopatológica do COC por meio de relato de caso submetido a tratamento cirúrgico e acompanhamento pós-operatório. Paciente de 11 anos apresentou aumento de volume em região maxilar à esquerda, próxima ao sulco nasolabial e sem sintomatologia dolorosa. Os exames radiográficos indicaram lesão radiolúcida, bem circunscrita e expansiva em maxila, que foi submetida a enucleação associada a ostectomia marginal das paredes corticais ósseas. O histopatológico revelou revestimento cístico com epitélio odontogênico ameloblástico, ninhos espalhados de células fantasmas e regiões eosinofílicas de material compatível com dentinóide. Evidenciou-se, assim, perfil clínico de COC, que pode ser confundido com outras lesões císticas ou tumorais, sendo essencial o diagnóstico por meio de análise histopatológica. A abordagem cirúrgica proporcionou adequado diagnóstico e tratamento. Após acompanhamento clínico e radiográfico, não houve recorrência do COC.

Calcifying odontogenic Cyst (COC) has been considering as benign pathological ill and rare occurrence in maxilla and mandible, there been showed odontogenic epithelial cystic lining demonstrating ghost cells with a propensity to calcify. In this article, we described the clinical and histopathological features from case reported who had undergone surgical approach and postoperative follow-up. A 11 year-old-girl had presented volumetric increased in left maxilla area near nasolabial fold. The radiography images had indicated radiolucent lesion, well-circumscribed and wide on cortical maxillary bone, which was undergone enucleation associated with marginal osteotomy on the bone cortical walls. The histopathological features showed cystic lining with odontogenic epithelium containing ghost cells and some areas with eosinophilic matrix material compatible dentinoid. Thus, it was evidenced a clinical features of COC which could be confused with other cystic or tumoral lesions, there being essential on diagnosis and treatment. After clinical and radiographic follow-up during 07 years, there was no recurrence of the COC.

Function of FAM20C in osteogenesis and odontogenesis / 国际生物医学工程杂志

Family with sequence similarity 20,member C(FAM20C),also known as dentin matrix protein 4 (DMP4),is a calcium-binding kinase for secreted phosphoproteins,and is highly expressed in mineralized tissues,which phosphorylates secretory calcium-binding phosphoproteins (SCPPs),thus modulating biomineralization.Mutations in FAM20C may cause the Raine syndrome,an autosomal recessive disorder characterized by generalized osteosclerosis with teeth defects,bone defects,hypophosphatemia and neonatal lethality.FAM20C plays an important role in the osteogenesis and odontogenesis through regulating the differentiation of osteoblast,ameloblast and odontoblast,as well as suppressing the production of phosphate-regulating hormone fibroblast growth factor 23 (FGF23).The research progress on the function of FAM20C in osteogenesis and odontogenesis is reviewed.