28 research outputs found
Preconditioning Triggered by Carbon Monoxide (CO) Provides Neuronal Protection Following Perinatal Hypoxia-Ischemia
No full textPerinatal hypoxia-ischemia is a major cause of acute mortality in newborns and cognitive and motor impairments in children. Cerebral hypoxia-ischemia leads to excitotoxicity and necrotic and apoptotic cell death, in which mitochondria play a major role. Increased resistance against major damage can be achieved by preconditioning triggered by subtle insults. CO, a toxic molecule that is also generated endogenously, may have a role in preconditioning as low doses can protect against inflammation and apoptosis. In this study, the role of CO-induced preconditioning on neurons was addressed in vitro and in vivo. The effect of 1 h of CO treatment on neuronal death (plasmatic membrane permeabilization and chromatin condensation) and bcl-2 expression was studied in cerebellar granule cells undergoing to glutamate-induced apoptosis. CO's role was studied in vivo in the Rice-Vannucci model of neonatal hypoxia-ischemia (common carotid artery ligature +75 min at 8% oxygen). Apoptotic cells, assessed by Nissl staining were counted with a stereological approach and cleaved caspase 3-positive profiles in the hippocampus were assessed. Apoptotic hallmarks were analyzed in hippocampal extracts by Western Blot. CO inhibited excitotoxicity-induced cell death and increased Bcl-2 mRNA in primary cultures of neurons. In vivo, CO prevented hypoxia-ischemia induced apoptosis in the hippocampus, limited cytochrome c released from mitochondria and reduced activation of caspase-3. Still, Bcl-2 protein levels were higher in hippocampus of CO pre-treated rat pups. Our results show that CO preconditioning elicits a molecular cascade that limits neuronal apoptosis. This could represent an innovative therapeutic strategy for high-risk cerebral hypoxia-ischemia patients, in particular neonates.© Queiroga et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Not every photograph is authorial
No full textO objetivo deste artigo é contribuir para o debate sobre autoria nafotografia, confrontando algumas dúvidas ou inexatidões extraídas do sensocomum a respeito da temática e condensadas em duas provocações: nem todofotógrafo é autor e nem toda fotografia produzida por um autor é autoral.Buscaremos em Michel Foucault, Laura González Flores e Tatiana Salem Levy,subsídios para a discussão, amparada por conceitos advindos da literatura, naqual autoria já é objeto de estudos há mais tempo.The aim of this paper is to contribute to the debate on authorship inphotography, considering some doubts or inaccuracies from commom senseabout the subject, condensed in two provocations: not every photographer is anauthor and not every photograph produced by an author is authorial. We willconsult Michel Foucault, Laura González Flores and Tatiana Salem Levy to aid ourdiscussion, supported by concepts from literature, in which authorship is studiedfor a longer time
Advances in canine mammary cancer: a role for inflammatory infiltrate in tumor microenvironment
No full textTese de Doutoramento em Ciências VeterináriasA inflamação faz parte dos principais “hallmarks” associados ao cancro e tem um papel relevante na carcinogénese mamária, relacionando-se com a agressividade tumoral e pior prognóstico. Nos tumores mamários dos canídeos (TMC) os estudos que se debruçam sobre o efeito das células imunitárias no prognóstico são escassos. Neste contexto, o presente trabalho foi realizado com o objetivo de fomentar o conhecimento sobre o papel das vias de sinalização compartilhadas pelo infiltrado de linfócitos T/macrófagos e importantes biomarcadores tumorais na progressão, agressividade e prognóstico destes tumores. A imunossupressão associada ao infiltrado de linfócitos T no tumor tem sido explicada pela capacidade inibitória das células T reguladoras (Treg) que impedem as atividades citotóxicas anti-tumorais. Com base nestas evidências, caracterizámos por imunohistoquímica as células Treg intratumorais (FoxP3+), bem como algumas citoquinas relacionadas com elas: TGFβ e IL-35. Os nossos resultados demonstraram que a maior imunorreactividade para o FoxP3 está presente em tumores com fenótipos mais agressivos: elevado grau histológico de malignidade (GHM), presença de embolos intravasculares e metástases nos linfonodos. Adicionalmente, mostrámos que as células Treg FoxP3+ intratumorais estão associadas com uma menor sobrevida total (ST), por análise univariada e multivariada. As células Treg secretam citoquinas inibidoras (TGFβ e IL-35), induzindo a tolerância aos tumores. Os nossos resultados sugerem uma associação entre o TGFβ e parâmetros de agressividade tumoral, refletindo o seu envolvimento na transformação maligna. Demonstraram também uma correlação positiva entre o FoxP3 intratumoral, os níveis de TGFβ, VEGF e CD31. Além disso, tumores com abundante TGFβ e com elevada expressão simultânea de TGFβ/FoxP3, FoxP3/VEGF, TGFβ/VEGF foram associados ao menor tempo de ST e a classe de tumores TGFβ/FoxP3 elevados revelou-se como um fator independente de mau prognóstico na análise multivariada. A IL-35 é uma citoquina secretada pelas células Treg que inibe a proliferação e função das células T. Demonstrámos que a sobre-expressão da IL-35 está associada com o estádio clínico mais avançado e com um prognóstico desfavorável na análise univariada e multivariada. Foi possível constatar, pela 1ª vez nos TMC, o valor prognóstico independente das células FoxP3+ Treg e da classe de tumores TGFβ/FoxP3 elevados. A IL-35 evidenciou-se ainda como um novo biomarcador capaz de prever a evolução clínica dos TMC. No seguimento deste trabalho, realizámos um amplo estudo que incidiu sobre as vias de sinalização compartilhadas pelo infiltrado de linfócitos T/macrófagos e importantes biomarcadores tumorais no microambiente dos TMC. Com esse propósito estudámos biomarcadores celulares importantes na carcinogénese mamária (COX-2, EGFR e c-kit), que estão frequentemente sobre-expressos ou mutados nos TMC. Constatámos uma associação significativa da imunoexpressão elevada da COX-2 com os linfócitos T CD3+ e macrófagos MAC387. Tumores com elevada expressão de COX-2/CD3 e COX-2/MAC estão associados com variáveis de agressividade tumoral e menor ST. Demonstrámos ainda que a expressão simultânea de COX-2+/EGFR+ está associada com maior número de células T CD3+ intratumorais e foi observada uma associação significativa e uma correlação positiva entre os linfócitos T CD3+ e a expressão de c-kit. Tumores com alta expressão de c-kit apresentaram maior número de células T CD3+ estando associados a um GHM elevado, presença de êmbolos intravasculares, metástases nos linfonodos e menor ST. Os resultados demonstram que as vias de sinalização que envolvem a COX-2, o EGFR e o c-kit são importantes, não só para a remodelação do microambiente do tumor mamário, mas também como alvos para a terapia imunológica anti-tumoral. Para complementar o trabalho, foi realizada uma experiência de co-cultura in vitro onde se pretendia demonstrar a potencial participação bidirecional das células tumorais e células imunitárias na regulação da COX-2. Os resultados mostraram que a co-cultura entre a linha celular de carcinoma mamário de cão Sh1b e as células mononucleares de sangue periférico de cão (PBMCs) induziram uma tendência para a sobre-expressão de COX-2 nas células cancerígenas. Por sua vez, a expressão de COX-2 pelos PBMCs, entre eles predominantemente macrófagos CD68+, foi significativamente atenuada pela cocultura com Sh1b. Em conformidade, a co-cultura com CD68+ THP1 diferenciada (dTHP1) provocou um aumento da produção intracelular de COX-2 pelas células Sh1b. A expressão intracelular de COX-2 pela dTHP1 diminuiu quando estas células foram tratadas com meio condicionado das células Sh1b. Estes resultados representam um avanço significativo na compreensão do papel da COX-2 na remodelação do microambiente tumoral nos TMC, nomeadamente através da imunomodulação dos macrófagos associados ao tumor. Globalmente, o presente trabalho demonstrou que, à semelhança do cancro de mama da mulher, também nos TMC as células inflamatórias no microambiente do tumor são capazes de orquestrar programas facilitadores da progressão tumoral.Cancer related inflammation is part of the major cancer hallmarks and has an important role in mammary carcinogenesis being involved in tumor aggressiveness and poor clinical outcome. In dogs only few studies have yet concentrated on the influence of immune cells in clinical outcome of dog mammary tumor patients. In this context, the present work was conducted with the main aim of up-to-date knowledge about the roles of the intertwined signaling pathways shared by T-lymphocytic/macrophage infiltrates and important tissue biomarkers in canine mammary tumors (CMT) progression, aggression and prognosis. Immunosuppression associated with tumor infiltrating T-lymphocytes (TILs) has been explained by the compartment of regulatory T-cells (Treg) that inhibit anti-tumor cytotoxic activities. Based on these evidences, first, we assessed, by immunohistochemistry, the characterization of intratumoral Treg cells, as well as some cytokines related by them: TGFβ and IL-35. Our results demonstrated that FoxP3 was present in tumors with more aggressive phenotypes: high histological grade of malignancy (HGM), presence of neoplastic intravascular emboli and presence of lymph node metastasis. Additionally, also showed that intratumoral FoxP3+ Treg cells were associated with shorter overall survival (OS), both in univariate and multivariate analysis. Tregs can secrete inhibitory cytokines (TGFβ and IL-35), inducing tumors tolerance. Present work suggests a link between TGFβ and parameters of tumor aggressiveness, reflecting its involvement in CMT malignant transformation. Our data demonstrated also a positive correlation between intratumoral FoxP3, TGFβ levels, VEGF and CD31. Moreover tumors with abundant TGFβ and with concurrent high expression of TGFβ/FoxP3, FoxP3/VEGF, TGFβ/VEGF were associated with shorter OS time and the TGFβ/FoxP3 tumors class retained the association with worse survival in multivariate analysis, arising as an independent predictor of poor prognosis. IL-35 is a Treg cellsecreted cytokine that inhibits T-cells proliferation and function and to the best of our knowledge, this is the first study that investigates the role of IL-35 in CMT development and clinical outcome. Our results showed that IL-35 overexpression was significantly associated with advancement of tumor stage and unfavorable prognosis by univariate and multivariate survival analysis. Interestingly our findings indicate, for the first time in dog mammary tumors, the independent prognostic value of FoxP3+ Treg cells and TGFβ/FoxP3 tumors class. Additionally the IL-35 seems to be a new biomarker to predict the CMT clinical outcome. For a more comprehensive approach about the role of immune cells in dog mammary carcinogenesis, we perform a wide study focused on the intertwined signaling pathways shared by T-lymphocytic/macrophage infiltrates and important tissue biomarkers in mammary tumor microenvironment. We focused on relevant cell biomarkers in mammary carcinogenesis, the COX-2, EGFR and c-kit which are often overexpressed or mutated in this type of tumor. Present data demonstrated a significant association of high COX-2 immunoexpression with CD3+ T-lymphocytes and MAC387 macrophages. Tumors with concurrent high COX-2/CD3 and high COX-2/MAC expression were associated with variables of tumor aggressiveness and shorter OS. Current results also demonstrated that the concurrent COX-2+/EGFR+ expression was associated with higher numbers of intratumoral CD3+ T-cells. Furthermore a significant association and a positive correlation between CD3+ T-lymphocytes and c-kit expression were observed. Tumors with high c-kit expression showed higher counts of CD3+ T-cells and were associated with high HGM, presence of neoplastic intravascular emboli, presence of lymph node metastasis, angiogenesis and shorter OS. The findings indicate that COX-2, EGFR and c-kit pathways are important not only for the remodeling of mammary tumor microenvironment but also could be a very important targets for tumor immunological therapy. Finally, in an in vitro co-culturing experiment, was our aim to prove the potential bidirectional crosstalk between tumor cells and immune cells on COX-2 regulation. Our data showed that co-culturing of canine mammary carcinoma cell line Sh1b and canine peripheral blood mononuclear cells (PBMCs) induced a trend of COX-2 overexpression in mammary cancer cells. In turn, COX-2 expression by PBMCs, among them predominantly CD68+ macrophages, was significantly attenuated by co-culture with Sh1b. In accordance, co-culture with CD68+ differentiated THP1 (dTHP1) prompted an intracellular production of COX-2 in Sh1b cells. The intracellular COX-2 expression from dTHP1 decreased when they were treated with conditioned medium from cultured Sh1b cells. Present results represents a significant advance on understanding the possible role of COX-2 in inducing a cancer tolerogenic microenvironment in CMT namely through a cancer associated macrophages immunomodulation. Overall present work demonstrated that, similarly to human breast cancer, also in CMT the inflammatory responses in mammary cancer sites are able to orchestrate hallmark-facilitating programs in tumor microenvironment.FCT (“Fundação para a
Ciência e a Tecnologia”) and POPH-QREN/FSE
(“Programa Operacional Potencial Humano-Quadro de Referência Estratégico Nacional/Fundo Social Europeu”
Comparative epidemiological study of breast cancer in humans and canine mammary tumors: insights from Portugal
No full textDogs spontaneously develop mammary gland tumors (MGT) and exhibit striking similarities in clinical and epidemiological characteristics to human breast cancer (HBC). Descriptive and comparative analysis of HBC and canine MGT with a focus on evaluating similarities and geographical distribution were the aims of this study. HBC cases were obtained from North Regional Oncological Registry (RORENO) (2010–2015) and canine MGT cases from Vet-OncoNet (2019–2022). Analyses were performed based on published and well accepted classification systems (ICD-O-3.2 for humans and Vet-ICD-O-canine-1). Age-standardized incidence risks (ASIR) of Porto district municipalities were calculated using 2021 Portuguese census (INE) and data from the Portuguese animal registration system (SIAC). Among 7,674 HBC cases and 1,140 MGT cases, a similar age and sex distribution pattern was observed. Approximately 69.2% of HBC cases were between 40 and 69 years old, while 66.9% of MGT cases were diagnosed between 7 and 12 years old (mean age of 9.6 years, SD = 2.6). In women, Invasive breast carcinoma (8500/3) was the most common histological type (n = 5,679, 74%) while in dogs it was the Complex Carcinoma (8983.1/3) (n = 205, 39%). Cocker and Yorkshire Terriers exhibited the highest relative risks (3.2 and 1.6, p < 0.05, respectively) when compared to cross breed dogs. The municipalities' ASIR of the two species exhibited a high correlation (R = 0.85, p < 0.01) and the spatial cluster analysis revealed similar geographic hotspots. Also, higher ASIR values both in women and dogs were more frequently found in urbanized areas compared to rural areas. This research sheds light on the shared features and geographical correlation between HBC and canine MGT, highlighting the potential of cross-species environmental oncology studies. Copyright © 2023 Carvalho, Niza-Ribeiro, Amorim, Queiroga, Severo, Ribeiro and Pinello.The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was financed through the financial support of the School of Medicine and Biomedical Sciences, ICBAS, University of Porto. Ana Isabel Ribeiro was supported by National Funds through FCT, under the Stimulus of Scientific Employment—Individual Support programme within the contract CEECIND/02386/2018
Tratamento da Sarcoidose**Actualização de conbecimentos apresentada à Faculdade de Medicina do Porto para satisfação da Prova Complementar de Doutoramento a que se refere a alinea b) do n.o 3 do arto 8 do Decreto-Lei n. o 308/70 de 18 de Agosto.
No full textSUMMARYThe author review the current concepts in the management of sarcoidosis, namely in the most common involved tissues (lungs and intrathoracic lymph nodes. It is done a brief commentary about incidence, etiology, pathogenesis and diagnosis of sarcoid disease. It is analized the techniques useful in assessing the extent and activity of sarcoidosis (chest radiographs, high resolution computorized tomography, pulmonary function tests, serum angiotensin – converting enzyme, Gallium67 scans, bronchoalveolar lavage).Corticosteroides are generally considered to be adequated treatment of sarcoidosis, but there is no establish criterious about when to start, the minimal effective dose, the duration, and the effect of therapy on the course of the granulomatous process. All patients with respiratory symptoms, abnormal pulmonary function test and diffuse changes on chest radiographs need therapy. Generally an initial dose of 0,5mg/kg of prednisone daily during the first three months, progressively reduced to 10-15 mg/day is adequate. A course of 12 to 18 months is recommended. In patients who do not respond to tolerable doses of steroids, alternative drug therapy must be considered (methotrexate, chlorambucil, azathioprine, cyclosporine, chloroquine). Two recent therapies are under consideration: inhaled steroids and lung transplantation. It’s considered particular aspects of extrapulmonary sarcoidosis treatment (ocular, cutaneous, cardiac, neurologic, renal, gastrointestinal, hepatic, osseous) and hypercalcaemia, hypercalcinuria.Sarcoidosis is a multisystem granulomatous disorder of unknown etiology with diverse clinical presentation and a variable natural history. In general prognostic is good (spontaneous resolution is common). Mortality is low (4%) and pulmonary fibrosis is the most frequent cause of death
Os gestos e os paladares da mesa camiliana
No full textDissertação de Mestrado em Estudos do Património apresentada à Universidade AbertaDo ponto de vista literário a novela camiliana tem sido amplamente estudada. Camilo
Castelo Branco é um autor que nunca se esgota. Mantém uma atualidade permanente capaz de
gerar interesse não só pela obra que produziu, mas pela forma como viveu a sua época. Vida e
obra entrecruzam-se, não só porque a sua escrita reflete o que viveu e o que imaginou, mas
também porque que a literatura preencheu a sua vida. Por isso continua a instigar leitores e
investigadores a novas reinterpretações, dando origem a leituras alternativas.
A presente dissertação, realizada no âmbito do Mestrado em Estudos do Património,
da Universidade Aberta, tem como objetivo valorizar e dinamizar a herança camiliana e
ampliar o conhecimento histórico e social do tempo do escritor, através do estudo e análise
das referências alimentares e gastronómicas registadas na obra de Camilo de Castelo
Branco.The novels by Camilo Castelo Branco have been extensively studied from a literary
perspective, since this is an author that does not wear out with time. Camilo retains a
lasting actuality susceptible to captivate attention, not just centred on his novels but also on
the way he lived his time. His life and work merge together, not just because his writing
reflect his life and imagination, but mostly because his existence was filled by literature.
This continues to encourage both readers and researchers to new interpretations about his
novels, thus emerging alternative readings.
This dissertation was produced as a part of the requirements for the degree of Master
on Heritage Studies to Open University. The objective of this study is to value and
popularize Camilo's literary heritage and to improve our historical and social awareness of
the writer's epoch, this being made through the study of both food and gastronomic
references contained in his novels
Diagnóstico laboratorial em animais de companhia
No full textO presente relatório visa a descrição das atividades desenvolvidas ao longo do estágio curricular no âmbito do diagnóstico laboratorial em animais de companhia, realizado no Hospital Veterinário de Portimão. O mesmo encontra-se dividido em três partes principais: a primeira expõe a casuística observada durante o estágio, sendo apresentada uma descrição estatística dos procedimentos acompanhados e realizados pela autora. A segunda parte abrange uma revisão bibliográfica subordinada ao tema exame citológico no diagnóstico de neoplasias: aplicação em dermatologia oncológica. A terceira parte, apresenta o relato e discussão de um estudo de caso sobre cistoadenoma das glândulas apócrinas observado num paciente canino durante o período de estágio. A análise citológica em Medicina Veterinária tem mostrado ser um dos mais preciosos auxiliares de diagnóstico oncológico na prática clínica de animais de companhia. Porém, o recurso a outras técnicas coadjuvantes, frequentemente, revela-se crucial para a obtenção de um diagnóstico definitivo; Abstract: Laboratory diagnosis in companion animals
This report aims to describe the activities carried out during the traineeship in the scope of laboratory diagnosis in companion animals which took place at Hospital Veterinário de Portimão. The report is divided in three main parts: the first one adresses the casuistry observed during the traineeship, presenting a statistical description of the procedures followed and performed by the author. The second part concerns a bibliographical review subordinated to the theme cytological exam in the diagnosis of neoplasias: application in oncological dermatology. The third part is the report and discussion of a case study on apocrine gland cystadenoma, observed in a canine patient during the internship period.
Cytological analysis in Veterinary Medicine has shown to be one of the most valuable oncological diagnosis aids in the clinical practice of companion animals. However, the use of other coadjuvant techniques often proves to be crucial for a definitive diagnosis
Ave Valley Survey Project, Porto, Portugal
No full textThe Ave Valley Survey Project is an archive resulting from a field survey in northrn Portugal which aimed to assess the impact of Roman annexation on a sophisticated Pre-Roman Iron Age culture. The archive contains files resulting from GIS analyses, geophysical surveys and a pottery database. It also contains images illustrating pottery finds and a variety of images resulting from the analysis of the data by the author
Expansão maxilar na dentição mista
No full textTese de mestrado, Medicina Dentária, Universidade de Lisboa, Faculdade de Medicina Dentária, 2011A deficiência transversal do maxilar superior é um dos problemas esqueléticos mais comuns da região craniofacial, sendo a expansão maxilar o procedimento mais utilizado para o seu tratamento durante o período da dentição mista. Este trabalho consiste numa revisão bibliográfica sobre a expansão maxilar na dentição mista. Procedeu-se a uma pesquisa sobre o tema na base de dados PUBMED, no Sistema Integrado das Bibliotecas da Universidade de Lisboa (sib.ul), na ADA - Center for Evidence-Based Dentistery e no motor de busca Google.com, tendo sido a última pesquisa realizada em Junho de 2011. A expansão maxilar é indicada não só para a correcção de discrepâncias maxilomandibulares transversais, como também para resolver problemas de falta de espaço, melhorar a respiração nasal ou aperfeiçoar a estética do sorriso. O protocolo de expansão maxilar é estabelecido após um exame clínico detalhado e deve ter em conta a variabilidade individual. São possíveis duas abordagens de tratamento no paciente em crescimento: a expansão lenta e a expansão rápida da maxila, estando disponíveis uma diversidade considerável de aparelhos expansores removíveis e fixos. O tratamento durante a fase inicial da dentição mista permite o melhor uso do potencial de crescimento do paciente, com necessidade reduzida de tratamentos mais complexos, menor risco de efeitos adversos iatrogénicos, melhor colaboração do paciente e resultados melhores e mais estáveis.The transverse deficiency of the maxilla is one of the most common skeletal problems of the craniofacial region. During mixed dentition, maxillary expansion is the most popular procedure to solve this anomaly. This study is a literature review of maxillary expansion in the mixed dentition. The author conducted a survey using PUBMED database, Sistema Integrado das Bibliotecas da Universidade de Lisboa (sib.ul), ADA - Center for Evidence-Based Dentistery and the search engine Google.com. The last research was conducted in June, 2011. Maxillary expansion is indicated not only for the correction of transverse jaw discrepancies, but also to solve lack of space problems, to improve nasal breathing or to aesthetically enhance the smile. The protocol is established after a detailed clinical examination and must take into account individual variability. There are two treatment approaches: slow and rapid maxillary expansion. These are available in a variety of removable and fixed expansion appliances. Early orthodontic treatment during mixed dentition is suggested to have many benefits, including better use of the patient’s growth potential, reduced need of extractions and surgery, lesser risk for adverse iatrogenic effects, better patient compliance, and better and stable results
Expansão maxilar na dentição mista
No full textTese de mestrado, Medicina Dentária, Universidade de Lisboa, Faculdade de Medicina Dentária, 2011A deficiência transversal do maxilar superior é um dos problemas esqueléticos mais comuns da região craniofacial, sendo a expansão maxilar o procedimento mais utilizado para o seu tratamento durante o período da dentição mista. Este trabalho consiste numa revisão bibliográfica sobre a expansão maxilar na dentição mista. Procedeu-se a uma pesquisa sobre o tema na base de dados PUBMED, no Sistema Integrado das Bibliotecas da Universidade de Lisboa (sib.ul), na ADA - Center for Evidence-Based Dentistery e no motor de busca Google.com, tendo sido a última pesquisa realizada em Junho de 2011. A expansão maxilar é indicada não só para a correcção de discrepâncias maxilomandibulares transversais, como também para resolver problemas de falta de espaço, melhorar a respiração nasal ou aperfeiçoar a estética do sorriso. O protocolo de expansão maxilar é estabelecido após um exame clínico detalhado e deve ter em conta a variabilidade individual. São possíveis duas abordagens de tratamento no paciente em crescimento: a expansão lenta e a expansão rápida da maxila, estando disponíveis uma diversidade considerável de aparelhos expansores removíveis e fixos. O tratamento durante a fase inicial da dentição mista permite o melhor uso do potencial de crescimento do paciente, com necessidade reduzida de tratamentos mais complexos, menor risco de efeitos adversos iatrogénicos, melhor colaboração do paciente e resultados melhores e mais estáveis.The transverse deficiency of the maxilla is one of the most common skeletal problems of the craniofacial region. During mixed dentition, maxillary expansion is the most popular procedure to solve this anomaly. This study is a literature review of maxillary expansion in the mixed dentition. The author conducted a survey using PUBMED database, Sistema Integrado das Bibliotecas da Universidade de Lisboa (sib.ul), ADA - Center for Evidence-Based Dentistery and the search engine Google.com. The last research was conducted in June, 2011. Maxillary expansion is indicated not only for the correction of transverse jaw discrepancies, but also to solve lack of space problems, to improve nasal breathing or to aesthetically enhance the smile. The protocol is established after a detailed clinical examination and must take into account individual variability. There are two treatment approaches: slow and rapid maxillary expansion. These are available in a variety of removable and fixed expansion appliances. Early orthodontic treatment during mixed dentition is suggested to have many benefits, including better use of the patient’s growth potential, reduced need of extractions and surgery, lesser risk for adverse iatrogenic effects, better patient compliance, and better and stable results
