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Covariance structure in the skull of Catarrhini: a case of pattern stasis and magnitude evolution

OLIVEIRA, Felipe Bandoni de; PORTO, Arthur; MARROIG, Gabriel
Fonte: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD Publicador: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
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36.91%
The study of the genetic variance/covariance matrix (G-matrix) is a recent and fruitful approach in evolutionary biology, providing a window of investigating for the evolution of complex characters. Although G-matrix studies were originally conducted for microevolutionary timescales, they could be extrapolated to macroevolution as long as the G-matrix remains relatively constant, or proportional, along the period of interest. A promising approach to investigating the constancy of G-matrices is to compare their phenotypic counterparts (P-matrices) in a large group of related species; if significant similarity is found among several taxa, it is very likely that the underlying G-matrices are also equivalent. Here we study the similarity of covariance and correlation structure in a broad sample of Old World monkeys and apes (Catarrhini). We made phylogenetically structured comparisons of correlation and covariance matrices derived from 39 skull traits, ranging from between species to the superfamily level. We also compared the overall magnitude of integration between skull traits (r(2)) for all Catarrhim genera. Our results show that P-matrices were not strictly constant among catarrhines, but the amount of divergence observed among taxa was generally low. There was significant and positive correlation between the amount of divergence in correlation and covariance patterns among the 30 genera and their phylogenetic distances derived from a recently proposed phylogenetic hypothesis. Our data demonstrate that the P-matrices remained relatively similar along the evolutionary history of catarrhines...

Evolução da modularidade no crânio de mamíferos; Evolution of modularity in the mammalian skull

Porto, Arthur Guimarães Carvalho
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/04/2009 PT
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A integração morfológica refere-se à organização modular das relações e conexões entre os caracteres, a qual influencia a direção e velocidade da mudança evolutiva, seja restringindo ou facilitando esta ao longo das diferentes direções do morfoespaço. Desta forma, a descrição de padrões e magnitudes de integração e a análise de suas conseqüências evolutivas são aspectos centrais do estudo da evolução de morfologias complexas. Aqui analisamos a integração morfológica no crânio de diferentes famílias de mamíferos, abordando as seguintes questões. Existem padrões de integração comuns a todos os grupos? Seriam esses padrões compatíveis com hipóteses a priori baseadas em ontogenia e função compartilhadas? Que tipos de respostas evolutivas á seleção poderiam ser produzidas por estes padrões? Para isso, digitalizamos representantes de 20 ordens e 40 famílias de mamíferos e então estimamos as matrizes de correlação e variância/covariância correspondentes, comparando-as entre si. Também comparamos cada um dos padrões de integração estimados a hipóteses a priori baseadas em ontogenia e função compartilhadas. Por fim, analisamos as repostas de cada uma das matrizes V/CV a vetores de seleção simulados. Nossos resultados apontam para um padrão de integração amplamente compartilhado entre todas as famílias...

Estudo comparativo da forma do crânio de cães braquicefálicos e mesaticefálicos por meio de técnicas de morfometria geométrica em três dimensões; Comparison of skull shape in brachycephalic and mesaticephalic dogs using three-dimensional morphometric techniques

Appollo-Hofmann, Fernanda
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/02/2009 PT
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Os padrões de conformação craniana resultantes da seleção das raças durante o processo de domesticação do cão evidenciam as relações entre as diversas partes que compõe o crânio. As raças braquicefálicas apresentam as maiores variações na forma quando comparadas aos mesaticefálicos, padrão este já descrito de forma qualitativa na literatura. Neste estudo, por meio da morfometria geométrica, as diferentes regiões do crânio e mandíbula de exemplares pertencentes aos dois grupos foram analisadas quantitativamente. Foram selecionados 52 crânios e 57 pontos anatômicos, digitalizados em três dimensões representando a forma destes crânios. As coordenadas foram utilizadas em análises multivariadas, buscando a caracterização quantitativa das diferenças na forma entre os grupos. Para o estudo da assimetria, foram analisados o crânio e mandíbula separadamente: regiões de contato da dentição com o crânio e com a mandíbula; caixa craniana; fossa mandibular; processo condilar; arco zigomático e processo coronóide. Para a caracterização dos padrões de covariância, as regiões de interesse foram analisadas aos pares: contato da dentição com o crânio e a com a mandíbula; fossa mandibular e processo condilar; arco zigomático e processo coronóide; dentes 4o pré-molar superior e 1o molar inferior; crânio e mandíbula. As análises estatísticas mostraram diferenças significativas entre os dois grupos...

Sinais clínicos de fratura da base do crânio e seu desempenho no diagnóstico dessa lesão; Clinical signs associated with skull base fracture and its performance on the diagnosis of this injury.

Solai, Cibele Andres
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/07/2013 PT
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36.97%
Introdução: A fragilidade dos sinais clínicos de fratura de base do crânio (FBC) para o diagnóstico dessa lesão, contraposta pela relevância atribuída a esses sinais, motivou a atual investigação, tendo em vista, sobretudo, a importância do diagnóstico dessa fratura nas intervenções iniciais ao doente traumatizado. Objetivos: Descrever o desempenho dos sinais clínicos de FBC para o diagnóstico dessa lesão; verificar o desempenho do hematoma periorbital e/ou rinorreia para diferenciar a fratura de fossa anterior das demais fraturas da base do crânio; descrever o tempo pós-trauma de aparecimento dos sinais clínicos em vítimas com e sem FBC; descrever o desempenho dos sinais de FBC na identificação precoce desse tipo de lesão; verificar a associação entre a presença de sinais clínicos de FBC e as variáveis idade do paciente e gravidade do trauma craniencefálico (TCE). Método: Estudo prospectivo do tipo follow up realizado por meio de observação estruturada de vítimas de TCE até 48 horas após trauma. Foram estudados indivíduos com idade 12 anos, com TCE contuso, atendidos na Unidade de Emergência Cirúrgica da Casa de Saúde Santa Marcelina entre agosto de 2012 e janeiro de 2013. Essa investigação foi focada nos sinais de FBC clássicos...

Osteossarcoma craniano em um cão; Skull osteosarcoma in a dog

Neuwald, Elisa Barp; Veiga, Denise de Castro; Gomes, Cristiano; Oliveira, Eduardo Conceição de; Contesini, Emerson Antônio
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
POR
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O osteossarcoma é a neoplasia óssea primária mais comum do esqueleto axial, sendo o crânio um local incomum de aparecimento desta neoplasia, ocorrendo em cerca de 12% dos cães com osteossarcoma do esqueleto axial. É um tumor mesenquimal malígno que afeta principalmente animais de meia idade a idosos de raças de médio e grande porte. Relata-se um caso de osteossarcoma craniano em um canino, sem raça definida, macho, não castrado, com 12 anos de idade, pesando 11kg, atendido no Hospital de Clínicas Veterinárias da Universidade Federal do Rio Grande do Sul o qual apresentava um aumento de volume na região craniana. Ao exame clínico constatou-se irritação à palpação da massa a qual era de consistência firme. Foram solicitadas radiografias cranianas e torácicas que revelaram rarefação, destruição e proliferação óssea desordenada com aumento de volume de tecidos moles compatível com neoplasia craniana, e padrão pulmonar misto intersticial e alveolar com presença de nódulos circunscritos radiopacos distribuídos aleatoriamente no campo pulmonar indicativos de metástases. Em função destes achados foi sugerida a eutanásia do animal ao proprietário. Foi realizada a necropsia onde observou-se que se tratava de um osteossarcoma craniano osteoblástico produtivo...

Size and shape variability in the skull of Myotis nigricans (Schinz, 1821) (Chiroptera : Vespertilionidae) from two geographic areas in Brazil; Variação de tamanho e forma no crânio de Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae) de duas áreas geográficas no Brasil

Bornholdt, Renata; Oliveira, Larissa Rosa de; Fabian, Marta Elena
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
37.06%
Uma análise quantitativa do dimorfismo sexual e da variação geográfica do crânio de Myotis nigricans (Schinz, 1821) é apresentada através da morfometria geométrica. Diferenças no tamanho e na forma do crânio foram avaliadas através de imagens bidimensionais das vistas lateral e ventral do crânio, onde foram estabelecidos 30 marcos anatômicos. Os resultados indicaram a existência de dimorfismo sexual no tamanho do centróide do crânio para ambas as vistas estudadas. As fêmeas foram maiores que os machos. Contudo, não foi detectado dimorfismo sexual na forma do crânio de M. nigricans. A variação geográfica esteve presente no tamanho e na forma do crânio. Espécimes do Sul do Brasil tiveram tamanho do centróide maior que os espécimes do Ceará apenas na vista lateral. Diferenças na forma do crânio foram estatisticamente significativas em ambas as vistas: os espécimes do Sul do Brasil apresentaram-se brevirostri e com grande expansão na região posterior do crânio, enquanto os espécimes do Ceará apresentaram crânios longirostri e sem expansão posterior da caixa craniana. São discutidos fatores ecológicos para estes fenômenos.; We present a quantitative analysis of sexual dimorphism and geographic variation in the skull of Myotis nigricans (Schinz...

Angiogenesis and skin carcinomas with skull base invasion: A case-control study

Cernea, C. R.; Ferraz, A. R.; de Castro, IV; Sotto, M. N.; Logullo, A. F.; Bacchi, C. E.; Potenza, A. S.
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 396-400
ENG
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Background. Some skin carcinomas may be very aggressive. Intensity of angiogenesis, measured by intratumoral vessel density using expression of CD34, has been associated with tumor aggressiveness. In this study, the expression of CD34 in basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) with skull base invasion was compared with that in tumors with good outcome.Methods. Expression of CD34 was graded as mild, moderate, and intense, in 24 BCCs and 11 SCCs with skull base invasion. The control group included 23 BCCs and 10 SCCs.Results. Intense expression of CD34 was noted in 25.00% of BCCs with skull base invasion, compared with 4.35% in the control group (p =.058). Regarding SCCs, intense expression of CD34 was found in 54.55% of aggressive tumors, compared with 10.00% in the control group (p = 133).Conclusions. A trend toward denser microvascular angiogenesis was observed in both BCCs and SCCs with skull base invasion compared with less aggressive controls. (C) 2004 Wiley Periodicals, Inc.

Skull and mandible formation in the cuckoo (Aves, Cuculidae): Contributions to the nomenclature in avian osteology and systematics

Posso, Sérgio Roberto; Donatelli, Reginaldo José
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 163-172
ENG
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The study of the contributions of different bones to the formation of the skeleton in birds is necessary: (1) to establish homologies in comparative anatomy; (2) to delimit each bone structure correctly, mainly in relation to the skull and mandible where the bones are fused to each other in adults; and (3) to standardize nomenclature in avian osteology. In this paper at least one young specimen belonging to each sub-family of Cuculidae was examined in order to identify each bone in terms of boundaries and contributions to skull and mandible formation. These cuckoos specimens were also compared with adults and young of turacos and hoatzin. The results show little variation of skull and jaw among the young cuckoos studied compared with the variations among adult specimens. However, it provides new suggestions for the boundaries and nomenclature of certain osseous structures in the skull and mandible of birds, specifically fissura zona flexoria craniofacialis, prominetia frontoparietalis, crista temporalis transversa, processus squamosalis, fossa laterosphenoidalis, tuberculum laterosphenoidale and processus retroangularis. This study also provides more reliable homologies for use in cladistic analysis and above all it contributes to the phylogenetic position of Cuculidae within Neognathae...

Size and shape variability in the skull of Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae) from two geographic areas in Brazil

Bornholdt,R.; Oliveira,LR.; Fabián,ME.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2008 EN
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We present a quantitative analysis of sexual dimorphism and geographic variation in the skull of Myotis nigricans (Schinz, 1821) assessed by geometric morphometrics. Differences in size and shape of skulls were investigated using 30 landmarks plotted on two-dimensional images of lateral and ventral views. Results of geometric morphometrics revealed sexual dimorphism in the centroid size of the skull in both views. Females were larger than males. Nevertheless, there was no sexual dimorphism in skull shape of M. nigricans. Geographic variation was detected in size and shape of the skull. South Brazilian specimens were significantly larger than Ceará specimens only in the lateral view. Differences in skull shape were statistically significant in both views: specimens from South Brazil were brevirostri and presented a more expanded skull in the posterior region while Ceará specimens were longirostri and do not present any expansion in the brain case. Ecological factors for these phenomena are discussed in the text.

Advances in Computed Tomography Evaluation of Skull Base Diseases

Prevedello,Luciano M.
Fonte: Fundação Otorrinolaringologia Publicador: Fundação Otorrinolaringologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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Introduction Computed tomography (CT) is a key component in the evaluation of skull base diseases. With its ability to clearly delineate the osseous anatomy, CT can provide not only important tips to diagnosis but also key information for surgical planning. Objectives The purpose of this article is to describe some of the main CT imaging features that contribute to the diagnosis of skull base tumors, review recent knowledge related to bony manifestations of these conditions, and summarize recent technological advances in CT that contribute to image quality and improved diagnosis. Data Synthesis Recent advances in CT technology allow fine-detailed evaluation of the bony anatomy using submillimetric sections. Dual-energy CT material decomposition capabilities allow clear separation between contrast material, bone, and soft tissues with many clinical applications in the skull base. Dual-energy technology has also the ability to decrease image degradation from metallic hardwares using some techniques that can result in similar or even decreased radiation to patients. Conclusions CT is very useful in the evaluation of skull base diseases, and recent technological advances can increase disease conspicuity resulting in improved diagnostic capabilities and enhanced surgical planning.

Panorama of Reconstruction of Skull Base Defects: From Traditional Open to Endonasal Endoscopic Approaches, from Free Grafts to Microvascular Flaps

Reyes,Camilo; Mason,Eric; Solares,C. Arturo
Fonte: Fundação Otorrinolaringologia Publicador: Fundação Otorrinolaringologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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Introduction A substantial body of literature has been devoted to the distinct characteristics and surgical options to repair the skull base. However, the skull base is an anatomically challenging location that requires a three-dimensional reconstruction approach. Furthermore, advances in endoscopic skull base surgery encompass a wide range of surgical pathology, from benign tumors to sinonasal cancer. This has resulted in the creation of wide defects that yield a new challenge in skull base reconstruction. Progress in technology and imaging has made this approach an internationally accepted method to repair these defects. Objectives Discuss historical developments and flaps available for skull base reconstruction. Data Synthesis Free grafts in skull base reconstruction are a viable option in small defects and low-flow leaks. Vascularized flaps pose a distinct advantage in large defects and high-flow leaks. When open techniques are used, free flap reconstruction techniques are often necessary to repair large entry wound defects. Conclusions Reconstruction of skull base defects requires a thorough knowledge of surgical anatomy, disease, and patient risk factors associated with high-flow cerebrospinal fluid leaks. Various reconstruction techniques are available...

Base of the skull morphology and Class III malocclusion in patients with unilateral cleft lip and palate

Tinano,Mariana Maciel; Martins,Milene Aparecida Torres Saar; Bendo,Cristiane Baccin; Mazzieiro,Ênio
Fonte: Dental Press International Publicador: Dental Press International
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2015 EN
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OBJECTIVE: The aim of the present study was to determine the morphological differences in the base of the skull of individuals with cleft lip and palate and Class III malocclusion in comparison to control groups with Class I and Class III malocclusion. METHODS: A total of 89 individuals (males and females) aged between 5 and 27 years old (Class I, n = 32; Class III, n = 29; and Class III individuals with unilateral cleft lip and palate, n = 28) attending PUC-MG Dental Center and Cleft Lip/Palate Care Center of Baleia Hospital and PUC-MG (CENTRARE) were selected. Linear and angular measurements of the base of the skull, maxilla and mandible were performed and assessed by a single calibrated examiner by means of cephalometric radiographs. Statistical analysis involved ANCOVA and Bonferroni correction. RESULTS: No significant differences with regard to the base of the skull were found between the control group (Class I) and individuals with cleft lip and palate (P > 0.017). The cleft lip/palate group differed from the Class III group only with regard to CI.Sp.Ba (P = 0.015). Individuals with cleft lip and palate had a significantly shorter maxillary length (Co-A) in comparison to the control group (P < 0.001). No significant differences were found in the mandible (Co-Gn) of the control group and individuals with cleft lip and palate (P = 1.000). CONCLUSION: The present findings suggest that there are no significant differences in the base of the skull of individuals Class I or Class III and individuals with cleft lip and palate and Class III malocclusion.

Skeletal gene expression in the temporal region of the reptilian embryos: implications for the evolution of reptilian skull morphology

Tokita, Masayoshi; Chaeychomsri, Win; Siruntawineti, Jindawan
Fonte: Springer International Publishing Publicador: Springer International Publishing
Tipo: Artigo de Revista Científica
EN_US
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Reptiles have achieved highly diverse morphological and physiological traits that allow them to exploit various ecological niches and resources. Morphology of the temporal region of the reptilian skull is highly diverse and historically it has been treated as an important character for classifying reptiles and has helped us understand the ecology and physiology of each species. However, the developmental mechanism that generates diversity of reptilian skull morphology is poorly understood. We reveal a potential developmental basis that generates morphological diversity in the temporal region of the reptilian skull by performing a comparative analysis of gene expression in the embryos of reptile species with different skull morphology. By investigating genes known to regulate early osteoblast development, we find dorsoventrally broadened unique expression of the early osteoblast marker, Runx2, in the temporal region of the head of turtle embryos that do not form temporal fenestrae. We also observe that Msx2 is also uniquely expressed in the mesenchymal cells distributed at the temporal region of the head of turtle embryos. Furthermore, through comparison of gene expression pattern in the embryos of turtle, crocodile, and snake species...

Facial artery musculomucosal flap for reconstruction of skull base defects

Xie, Liyue
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
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Facial Artery Musculomucosal Flap in Skull Base Reconstruction Xie L. MD, Lavigne F. MD, Rahal A. MD, Moubayed SP MD, Ayad T. MD Introduction: Failure in skull base defects reconstruction can have serious consequences such as meningitis and pneumocephalus. The nasoseptal flap is usually the first choice but alternatives are necessary when this flap is not available. The facial artery musculomucosal (FAMM) flap has proven to be successful in head and neck reconstruction but it has never been reported in skull base reconstruction. Objective: To show that the FAMM flap can reach some key areas of the skull base and be considered as a new alternative in skull base defects reconstruction. Methods: We conducted a cadaveric study with harvest of modified FAMM flaps, endoscopic skull base dissection and maxillectomies in 13 specimens. Measures were taken for each harvested FAMM flap. Results: The approximate mean area for reconstruction from the combination of the distal FAMM and the extension flaps is 15.90 cm2. The flaps successfully covered the simulated defects of the frontal sinus, the ethmoid areas, the planum sphenoidale, and the sella turcica. Conclusion: The FAMM flap can be considered as a new alternative in the reconstruction of skull base defects. Modifications add extra length to the traditional FAMM flap and can contribute to a tighter seal of the defect as opposed to the FAMM flap alone.; Le lambeau musculomuqueux de la joue dans la reconstruction de la base du crâne Xie L. MD...

Carotid artery injury during endoscopic endonasal skull base surgery: incidence and outcomes

Gardner, P.; Tormenti, M.; Pant, H.; Fernandez-Miranda, J.; Snyderman, C.; Horowitz, M.
Fonte: Lippincott Williams & Wilkins Publicador: Lippincott Williams & Wilkins
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
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BACKGROUND: Injury to the internal carotid artery (ICA) during endoscopic endonasal skull base surgery is a feared complication that is not well studied or reported. OBJECTIVE: To evaluate the incidence, to identify potential risk factors, and to present management strategies and outcomes of ICA injury during endonasal skull base surgery at our institution. METHODS: We performed a retrospective review of all endoscopic endonasal operations performed at our institution between 1998 and 2011 to examine potential factors predisposing to ICA injury. We also documented the perioperative management and outcomes after injury. RESULTS: There were 7 ICA injuries encountered in 2015 endonasal skull base surgeries, giving an incidence of 0.3%. Most injuries (5 of 7) involved the left ICA, and the most common diagnosis was chondroid neoplasm (chordoma, chondrosarcoma; 3 of 7 [2% of 142 cases]). Two injuries occurred during 660 pituitary adenoma resections (0.3%). The paraclival ICA segment was the most commonly injured site (5 of 7), and transclival and transpterygoid approaches had a higher incidence of injury, although neither factor reached statistical significance. Four of 7 injured ICAs were sacrificed either intraoperatively or postoperatively. No patient suffered a stroke or neurological deficit. There were no intraoperative mortalities; 1 patient died postoperatively of cardiac ischemia. One of the 3 preserved ICAs developed a pseudoaneurysm over a mean follow-up period of 5 months that was treated endovascularly. CONCLUSION: ICA injury during endonasal skull base surgery is an infrequent and manageable complication. Preservation of the vessel remains difficult. Chondroid tumors represent a higher risk and should be resected by surgical teams with significant experience.; Paul A. Gardner...

What are the limits of endoscopic sinus surgery?: The expanded endonasal approach to the skull base

Snyderman, C.; Pant, H.; Carrau, R.; Prevedello, D.; Gardner, P.; Kassam, A.
Fonte: Keio Journal of Medicine Publicador: Keio Journal of Medicine
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
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The advent of endoscopic technologies and techniques has expanded the limits of conventional endoscopic sinus surgery. The expanded endonasal approach describes a series of surgical modules in the sagittal and coronal planes that allow surgical access to the entire ventral skull base. The sagittal plane extends from the frontal sinus to the second cervical vertebra. The coronal plane extends from the midline to the roof of the orbit, the floor of the middle cranial fossa, and the jugular foramen. Key principles of endonasal skull base surgery are choosing a surgical corridor that minimizes the need for neural and vascular manipulation, team surgery, use of the endoscope to enhance visualization, and bimanual tumor dissection under direct visualization. Particular challenges of the expanded endonasal approach are identification of anatomical structures using unfamiliar landmarks, hemostasis, and dural reconstruction. Over the last decade with more than 1000 completely endonasal skull base surgeries, we have demonstrated that endoscopic endonasal surgery of the skull base can be performed with minimal morbidity and mortality. The introduction of the septal mucosal flap for dural reconstruction has decreased the incidence of postoperative cerebrospinal fluid leaks to less than 5%. Early data suggests that oncological outcomes for malignant sinonasal tumors with skull base involvement are comparable to conventional techniques. Proper training in endonasal surgical techniques is essential to prevent unnecessary morbidity and achieve good outcomes.; Carl H. Snyderman...

Functional relationship between skull form and feeding mechanics in Sphenodon, and implications for diapsid skull development

Curtis, N.; Jones, M.E.H.; Shi, J.; O'Higgins, P.; Evans, S.E.; Fagan, M.J.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
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The vertebrate skull evolved to protect the brain and sense organs, but with the appearance of jaws and associated forces there was a remarkable structural diversification. This suggests that the evolution of skull form may be linked to these forces, but an important area of debate is whether bone in the skull is minimised with respect to these forces, or whether skulls are mechanically ‘‘over-designed’’ and constrained by phylogeny and development. Mechanical analysis of diapsid reptile skulls could shed light on this longstanding debate. Compared to those of mammals, the skulls of many extant and extinct diapsids comprise an open framework of fenestrae (window-like openings) separated by bony struts (e.g., lizards, tuatara, dinosaurs and crocodiles), a cranial form thought to be strongly linked to feeding forces. We investigated this link by utilising the powerful engineering approach of multibody dynamics analysis to predict the physiological forces acting on the skull of the diapsid reptile Sphenodon. We then ran a series of structural finite element analyses to assess the correlation between bone strain and skull form. With comprehensive loading we found that the distribution of peak von Mises strains was particularly uniform throughout the skull...

Alterações antropométricas na base do crânio em crianças com craniostenose sagital submetidas à correção cirúrgica; Anthropometric changes in the skull base in children with sagittal craniosynostosis submitted to surgical correction

Lucio, José Erasmo Dal'Col
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/04/2011 PT
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37.15%
Craniostenose é o fechamento precoce de uma ou mais suturas cranianas, levando ao redirecionamento do crescimento craniofacial e à deformidade do crânio. Estudos têm pesquisado o impacto da fusão da sutura sagital na base do crânio, focalizando a morfologia da base do crânio na presença de craniostenose sagital isolada (escafocefalia), enquanto outros têm avaliado o crescimento da base do crânio, antes e após a cirurgia. Este estudo teve como objetivo realizar as medidas antropométricas da base do crânio em crianças com escafocefalia, avaliar a influência da correção cirúrgica no remodelamento da base do crânio e nas medidas antropométricas. Foram operadas 21 crianças com diagnóstico clínico e radiológico de escafocefalia, entre abril de 2007 e outubro de 2008, sendo realizadas medidas antropométricas na base do crânio, antes e após 1 ano do tratamento cirúrgico. As medidas foram o índice craniano (IC), distância entre a crista galli e o tubérculo selar (CG-TS), distância entre a crista galli e o meato acústico interno (CG-MAI), distância entre os forames ovais (FO-FO), distância entre os meatos Acústicos internos (MAI-MAI), o ângulo da base do crânio Â1) e o ângulo entre o násio, centro selar e básio (Â2). Houve normalização do IC em todas as crianças...

Advances in Magnetic Resonance Imaging of the Skull Base

Kirsch,Claudia F.E.
Fonte: Fundação Otorrinolaringologia Publicador: Fundação Otorrinolaringologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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Introduction Over the past 20 years, magnetic resonance imaging (MRI) has advanced due to new techniques involving increased magnetic field strength and developments in coils and pulse sequences. These advances allow increased opportunity to delineate the complex skull base anatomy and may guide the diagnosis and treatment of the myriad of pathologies that can affect the skull base. Objectives The objective of this article is to provide a brief background of the development of MRI and illustrate advances in skull base imaging, including techniques that allow improved conspicuity, characterization, and correlative physiologic assessment of skull base pathologies. Data Synthesis Specific radiographic illustrations of increased skull base conspicuity including the lower cranial nerves, vessels, foramina, cerebrospinal fluid (CSF) leaks, and effacement of endolymph are provided. In addition, MRIs demonstrating characterization of skull base lesions, such as recurrent cholesteatoma versus granulation tissue or abscess versus tumor, are also provided as well as correlative clinical findings in CSF flow studies in a patient pre- and post-suboccipital decompression for a Chiari I malformation. Conclusions This article illustrates MRI radiographic advances over the past 20 years...

Ganglioglioma with lytic skull lesions: a case report

Gurkanlar,D.; Kocak,H.; Yucel,E.; Aciduman,A.; Gunaydin,A.; Ekinci,Ö.; Keskil,S.
Fonte: Neurocirugía Publicador: Neurocirugía
Tipo: info:eu-repo/semantics/article; journal article; info:eu-repo/semantics/publishedVersion Formato: text/html; application/pdf
Publicado em 01/04/2007 ENG
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Gangliogliomas represent only 0.4% of central nervous system neoplasms and 1.3% of brain tumors. They are benign neoplasms with low morbidity and mortality and the patients usually present with seizures, but there has been no adult ganglioglioma with lytic skull lesion. A 49-year-old right handed woman suffering from generalized epileptic seizures was admitted to our hospital. She had also left hemiparesis with 4/5 motor strength. Magnetic resonance imaging and immunohistochemical studies revealed WHO Grade II ganglioglioma. Skull X-ray showed the lytic skull lesions. We have to consider gangliogliomas in the differential diagnosis of lytic skull lesions.