Introduction: The objective of this study is to investigate the role of osteoblasts in the pathophysiology of premature suture fusion in infants. Methods: Bone and periosteal tissue from fused and patent cranial sutures and adjacent bone were harvested from infants undergoing surgery for craniosynostosis and used to develop primary osteoblast cell cultures. Dural tissue was obtained from neurosurgical procedures in order to generate an osteoblast-dural co-culture. Osteoblast proliferation, differentiation, mineralization, protein expression (Noggin, BMP3 and Runx2) and response to exogenous FGF2 stimulation were assessed. Results: Cell cultures demonstrated significant (p<0.05) regional variations in osteoblast proliferation, differentiation markers and in vitro bone nodule formation. The expression of anti-osteogenic molecules (Noggin and BMP3) was decreased in osteoblasts from fused suture regions. Conclusion: The creation of a pro-osteogenic environment through the decreased expression of anti-osteogenic signalling molecules and increased expression of osteogenic factors may be responsible for premature suture fusion in infants.

Introduction: The objective of this study is to investigate the role of osteoblasts in the pathophysiology of premature suture fusion in infants. Methods: Bone and periosteal tissue from fused and patent cranial sutures and adjacent bone were harvested from infants undergoing surgery for craniosynostosis and used to develop primary osteoblast cell cultures. Dural tissue was obtained from neurosurgical procedures in order to generate an osteoblast-dural co-culture. Osteoblast proliferation, differentiation, mineralization, protein expression (Noggin, BMP3 and Runx2) and response to exogenous FGF2 stimulation were assessed. Results: Cell cultures demonstrated significant (p<0.05) regional variations in osteoblast proliferation, differentiation markers and in vitro bone nodule formation. The expression of anti-osteogenic molecules (Noggin and BMP3) was decreased in osteoblasts from fused suture regions. Conclusion: The creation of a pro-osteogenic environment through the decreased expression of anti-osteogenic signalling molecules and increased expression of osteogenic factors may be responsible for premature suture fusion in infants.

Craniosynostosis is the premature fusion of one or more cranial sutures in the developing skull. If left untreated, craniosynostosis can result in developmental delays, blindness, deafness, and other impairments resulting from an increase in the intracranial pressure. In many cases, the treatment consists of complex calvarial vault reconstruction with the hope of restoring a normal skull appearance and volume. Re-synostosis, the premature re-closure following surgery, occurs in up to 40% children who undergo surgery. If this occurs, a second surgery is needed to remove portions of the fused skull in an attempt to correct the deformities and/or relieve an increase in intracranial pressure. These subsequent surgeries are associated with an incredibly high incidence of life threatening complications. To address this unmet clinical need we have developed strategies to delay the post-operative bone growth in a clinically relevant murine model of re-synostosis. The overall objective of this thesis was to develop a hydrogel based therapy to delay rapid bone regeneration in a murine model of re-synostosis. The overall hypothesis was that delivery of key BMP inhibitors involved in regulating normal suture development and regeneration will delay the rapid bone growth that in seen in a pediatric murine model of re-synostosis. The overall approach is to use micro-computed tomography (µCT) to determine the time course of suture fusion and to identify genes associated with key developmental time points, to develop a pediatric specific mouse model that displays rapid re-synostosis, and lastly to develop a hydrogel based therapy to delay the re-synostosis of this cranial defect.

Um dos grupos de doenças mais importante que acomete o desenvolvimento da caixa craniana humana é o das craniossinostoses, caracterizado pelo fechamento prematuro de uma ou mais suturas cranianas. Entre as formas mendelianas das craniossinostoses sindrômicas, mutações dominantes em FGFR2 são uma das causas mais frequentes e estão associadas às síndromes de Apert, de Crouzon e de Pfeiffer. A sinalização intracelular subseqüente à ativação de FGFR2, tanto selvagem quanto mutante, é bastante intrincada e pode sofrer inúmeras bifurcações. As porções iniciais destas vias, imediatamente subsequentes à ativação do receptor, são relativamente bem compreendidas. Grande parte, porém, do controle dessas vias, principalmente no que tange a regulação transcricional e sua associação com alterações em comportamentos celulares, não é entendido. Assim sendo, os objetivos gerais deste trabalho foram: 1) estudar o potencial de diferenciação e o perfil diferencial de transcrição gênica de culturas primárias de células fibroblastóides isoladas a partir do periósteo das suturas coronais de pacientes acometidos por síndrome de Apert (heterozigotos para a mutação de ganho de função p.Ser252Trp em FGFR2, a mutação mais comum em pacientes com esta síndrome) e 2) estudar o potencial de diferenciação osteogênico e o perfil transcricional respectivamente de células mesenquimais e de tecido provenientes de sutura coronal de um modelo murino para Síndromes de Crouzon/Pfeiffer (heterozigotos para a mutação p.Cys342Tyr em Fgfr2, a mutação mais comum associada a estas síndromes). Certificamo-nos da expressão gênica e proteica de FGFR2 nas células fibroblastóides humanas e de Fgfr2 nas células mesenquimais murinas. Em seguida, testamos o potencial osteogênico (in vitro e in vivo ) e adipogênico (in vitro ) das células de pacientes com Síndrome de Apert, comparadas a células do mesmo tecido mas de indivíduos sem esta mutação e o potencial osteogênico (in vitro ) das células mesenquimais de camundongos portadores da mutação p.Cys342Tyr em Fgfr2, comparadas a células também das suturas coronais mas de animais selvagens. O potencial de diferenciação das células mutantes, nos dois grupos de experimentos, foi muito aumentado em relação ao potencial das células livres destas mutações. Conduzimos experimentos de microarrays de expressão gênica (sistema CodeLink) com 7 amostras de culturas primárias de células de pacientes com S. de Apert e as comparamos com 7 amostras de culturas primárias controles. Identificamos 263 genes com valores de expressão estatisticamente diferentes (SNR &#8805; |0.4|, P &#8804; 0,05) nas amostras de pacientes com S. de Apert quando comparadas às controles (118 superexpressos, 145 subexpressos). Categorias funcionais enriquecidas foram regulação de proliferação celular, metabolismo de nucleotídeos, regulação de expressão gênica, adesão celular, organização de matriz extracelular e cascata PI3K MAPK. Para a validação deste experimento constatamos superexpressão, por PCR em tempo real, de genes identificados como superexpressos na assinatura de expressão associada às células mutadas, além de verificarmos o mesmo comportamento destes genes em células controles tratadas com FGF2 exógeno para superativação do receptor. Os experimentos de expressão gênica com os tecidos de suturas coronais do modelo murino foram feitos com 15 amostras de tecidos de animais mutantes em 3 grupos de 5 e comparadas a amostras de mesmo tecido de animais selvagens agrupadas da mesma forma. Identificamos três listas de genes diferencialmente expressos: a primeira contendo 188 transcritos (P &#8804;0,05, FC &#8805; 1,5,sendo 91 superexpressos e 97 subexpressos), e as outras duas filtradas previamente para coeficiente de variação &lt; 50% dentro de cada grupo, contendo 488 transcritos (P &#8804;0,05, FC &#8805; 1,2, sendo 183 superexpressos e 305 subexpressos) e 31 transcritos (P &#8804;0,05, FC &#8805; 1,5, sendo 11 superexpressos e 20 subexpressos). Categorias funcionais mais enriquecidas foram crescimento, proliferação e ciclo celular, diferenciação celular, sinalização célula-célula, resposta imune mediada por células e sinalização por receptor Wnt. Estes resultados nos permitiram: a) demonstrar que células fibroblastóides de periósteo craniano de paciente portadores de S. de Apert (mutação p.Ser252Trp em FGFR2) e células mesenquimais do modelo murino para S. de Crouzon e Pfeiffer, portador da mutação p.Cys342Tyr em Fgfr2, apresentam potencial osteogênico aumentado, agregando evidências que sugerem que esta alteração de comportamento celular tem função fundamental no desencadeamento das craniossinostoses nestas síndromes; b) revelar assinaturas de expressão gênicas associadas a estas mutações nas condições estudadas, que podem reger este comportamento celular anormal; c) identificar um novo grupo de genes associados à patofisiologia da Síndrome de Apert ou às características fenotípicas do modelo murino investigado, podendo também ser genes candidatos a outras craniossinostoses de causa desconhecida. / Craniosynostosis is one of the most important group of diseases linked to the development of the human skull and is characterized by the premature fusion of one or more cranial sutures. Dominant mutations in FGFR2 are frequent molecular causes amongst the mendelian inherited forms of the syndromic craniosynostosis and are associated to Apert, Crouzon and Pfeiffer syndromes. The intracellular signaling pathways following the activation of wild type or mutant FGFR2 are very complex due to several possible bifurcations. The initial portions of these pathways, immediately following the receptor activation, are relatively well delineated. However the great majority of the events related to the control of these pathways is still not well understood, mainly concerning its transcriptional regulation and its association to other cell behavior anomalies. Therefore the key scopes of this work were: 1) to study the differentiation potential and the differential gene expression profile of primary fibroblastoid cell cultures isolated from the periosteum of the coronal sutures of Apert Syndrome patients (heterozygous for the mutation p.Ser252Trp in FGFR2, the most common cause of the Apert Syndrome condition) and 2) to study the osteogenic differentiation potential and the transcriptional profile of mesenchymal cells and tissue isolated from the coronal sutures of a mouse model for the Crouzon and Pfeiffer Syndromes (heterozygous for the p.Cys342Tyr mutation in Fgfr2, the mutation most commonly associated to these syndromes). We assured the FGFR2 /FGFR2 gene and the protein expression in human fibroblastoid cells and Fgfr2 /Fgfr2 expression in the mesenchymal murine cells. We tested the (in vitro and in vivo ) osteogenic and the (in vitro ) adipogenic potentials of the Apert Syndrome patients cells compared to cells from the same tissue but from subjects without this mutation and the (in vitro ) osteogenic potential of mesenchymal cells from mice bearing the p.Cys342Tyr mutation in Fgfr2 compared to coronal suture cells but from wild type mice. On both experiments the differentiation potential of the mutant cells were very increased when compared to the potential of the wild type cells. We conducted gene expression microarray experiments (CodeLink system) using 7 samples from primary cultures of cells from Apert Syndrome patients compared to 7 samples from primary control cultures. We identified 263 genes with significantly different expression (SNR &#8805; |0.4|, P &#8804; 0,05) associated to the Apert Syndrome profile (118 upregulated, 145 downregulated). Enriched functional cathegories were regulation of cell proliferation, nucleotide metabolism, gene expression regulation, cell adhesion, extracellular matrix organization and PI3K MAPK cascades. In order to validate this gene expression signature we confirmed through Real-Time PCR the upregulation of genes identified as upregulated in the Apert cell profile in samples from the microarray experiment and in control cells treated with exogenous overactivate the receptor. The gene expression experiments with the coronal suture tissues from the mouse model were performed with 15 samples of mutant animal tissue in 3 groups of 5 and compared to samples from the same tissue of wild type animals, with identical grouping. We identified three sets of differentially expressed genes: the first set containing 188 transcripts (P &#8804;0,05, FC &#8805; 1,5, 91 upregulated e 97 downregulated), and the other two filtered for coeficient of variation &lt; 50% in each group, containing 488 transcripts (P &#8804;0,05, FC &#8805; 1,2, sendo 183 upregulated and 305downregulated) e 31 transcripts (P &#8804;0,05, FC &#8805; 1,5, 11 upregulated and 20 downregulated). The most enriched functional categories were growth, proliferation and cell cycle, cell differentiation, cell-to-cell signaling, cell mediated immune response and Wnt receptor signaling. These results allowed us: a) to demonstrate that fibroblastoid cells from coronal periosteum PF Apert Syndrome patients (p.Ser252Trp mutation in FGFR2) and mesenchymal cells from the coronal tissue of the mouse model for Crouzon and Pfeiffer syndromes (bearing the p.Cys342Tyr in Fgfr2) have enhanced osteogenic potential, summoning evidences suggesting that this cell behavior alteration have a fundamental role to the craniosynostotic process in these syndromes; b) to unravel gene expression signatures linked to these mutations in the studied conditions, that could orchestrate this abnormal cell behavior; c) to identify a ser of genes associated to the pathophysiology of Apert Syndrome and to the phenotypic characteristics of the animal model investigated, which might be candidate genes to other craniosynostosis of unknown cause.

Para melhor conhecer as condições de saúde bucal, associação com fissuras labiopalatinas, alterações de tecido mole e prevalência de anomalias dentárias em pacientes com síndromes craniofaciais, foram avaliados dois grupos de pacientes, sendo 19 com craniossinostoses múltiplas sindrômicas (síndromes de Apert, Crouzon, Pfeiffer e Saethre-Chotzen) e 15 com síndrome de Treacher Collins. O estudo foi realizado por meio de exame clínico e radiográfico e avaliação de índices de placa (PHP e índice de placa visível), cárie (ceo e CPOD) e gengival. Também foi investigada a eficácia do controle de higiene bucal realizado pelos pacientes. Ambos os grupos apresentaram alto índice de placa e baixa eficácia de escovação dentária, sem diferença estatisticamente significativa entre pacientes com e sem sindactilia no grupo de craniossinostoses múltiplas sindrômicas. Apesar do acúmulo de placa, os índices de cárie e gengival encontrados não foram expressivos. A maioria dos pacientes com síndrome de Treacher Collins apresentava fissura labiopalatina, especialmente fissura isolada de palato. Não foi observada presença de fissura labiopalatina no grupo de craniossinostoses múltiplas sindrômicas, que por sua vez apresentou ocorrência bastante freqüente de hiperplasia da mucosa palatina, notadamente em pacientes com síndromes de Apert e Crouzon. Houve alta prevalência de anomalias dentárias em ambos os grupos, especialmente opacidades de esmalte e agenesias dentárias, que poderiam ser características adicionais relacionadas às síndromes não relatadas na literatura até o momento. Com base nestes resultados, é proposto um protocolo de conduta terapêutica odontológica para pacientes com as referidas síndromes. / Two groups of patients were evaluated in an attempt to achieve more information on the oral health status, association with cleft lip and palate, soft tissue alterations and prevalence of dental anomalies in patients with craniofacial syndromes. One group comprised 19 patients with craniosynostosis syndromes (Apert, Crouzon, Pfeiffer and Saethre-Chotzen syndromes) and the other group included 15 patients with Treacher Collins syndrome. The study was conducted by means of clinical and radiographic examination and evaluation of plaque (PHP and visible plaque index), caries (dmf-t and DMFT) and gingival indexes. The efficacy of oral hygiene control performed by the patients was also investigated. Both groups displayed high plaque index and poor efficacy of toothbrushing, with no statistically significant difference between patients with and without syndactyly in the group with craniosynostosis syndromes. Despite the plaque accumulation, the caries and gingival indexes found were not meaningful. Most patients with Treacher Collins syndrome had cleft lip and palate, especially isolated cleft palate. No cases of cleft lip and palate were found in the group of craniosynostosis syndromes, which in turn displayed frequent occurrence of lateral palatal swellings, especially among patients with Apert and Crouzon syndromes. There was a high prevalence of dental anomalies for both groups, especially enamel opacities and tooth agenesis, which might be additional characteristics related to the syndromes that have not been reported in the literature so far. Based on these results, a dental therapeutic protocol is proposed for patients with the aforementioned syndromes.

In normal cranial suture development, the cranial sutures close at predetermined periods of development to allow the brain the capability to grow in a malleable environment. However, in craniosynostosis, cranial sutures prematurely fuse before birth which can lead to a wide range of developmental issues and complications. Craniosynostosis can be categorized as nonsyndromic which involves the sole fusion of one or more of the cranial sutures, or syndromic in which cranial sutures fuse as well as other abnormalities associated with a genetic disorder. Past research has identified three candidate genes that could be possible disease causing mutations in nonsyndromic sagittal craniosynostosis. The mutations were found were in ITGAV, SLC30A9, and BAMBI. Using zebrafish as a model organism, we assessed the phenotypic effects of mutating itgav, slc30a9, and bambia associated with craniosynostosis. Phenotypic analysis of heterozygous itgav mutants showed when itgav is mutated there is increased bone formation and abnormal suture development. Due to the phenotype seen in zebrafish, it is proposed when mutated, ITGAV can help produce craniosynostosis.

BACKGROUND: Pleiotropy is a biological phenomenon of a single gene exhibiting influence over several different seemingly disparate phenotypes. This phenomenon poses significant challenges to fully understanding the etiologies of many different Mendelian diseases. Two such Mendelian diseases are Idiopathic Hypogonadotropic Hypogonadism (IHH) and Craniosynostosis (CS). IHH results from the failure of differentiation, migration, secretion, or action of the GnRH neurons resulting in absent puberty and infertility. CS is characterized by premature fusion of one or more of the cranial sutures resulting in dysmorphic shape of the skull that can lead to life-threatening raised intercranial pressure requiring surgical intervention. Thus far, 77 genes have been implicated in IHH and 128 genes have been implicated CS, both representing ~50% of the cases in their respective diseases. Recent research has suggested a shared molecular landscape in CS and IHH but the full ensemble of this overlap is not known. OBJECTIVE: This study will attempt to utilize human genetics, bioinformatics, statistics, phenotype data of IHH patients, and the prior literature in order to ascertain the full extent of the shared biology of IHH and CS. METHODS: The gene sets of both IHH and CS were used in gene overlap statistical analysis to investigate shared genetics. Whole exome sequencing data from 1,395 patients from the IHH cohort of the Massachusetts General Hospital were used for gene-variant burden analysis to determine genetic overlap with CS. Detailed physician notes from this cohort were used to determine phenotypic presence of CS in IHH. Conversely, evidence of reproductive phenotypes in genetically characterized CS patients was gathered from the reported CS gene literature. The CS and IHH gene sets were also bioinformatically analyzed using both the Metascape and DAVID bioinformatic platforms for pathway annotation, protein-protein interaction (PPI), and functional interactions to provide evidence for the mechanism of shared biology. RESULTS: Of the 128 CS genes and 77 IHH genes, 4 were determined to be causal for both diseases with a further 3 considered as potentially causal candidates for both diseases. The 4 overlapping causal genes were tested using three different methods and this overlap was determined to be of statistical significance (p<0.05). Furthermore, the phenotypic review revealed that while there was not a significant enrichment for CS phenotypes in the IHH cohort, the literature review yielded 49 of 128 CS genes that were reported with phenotypic evidence of failure of the hypothalamic-pituitary portion of the HPG axis. Gene-variant burden analysis yielded nominal (p<0.05) enrichment in the IHH cohort for 17 CS genes, of which 3 were significant after Bonferroni multiple testing correction (p<0.00039). The CS/IHH gene sets were both enriched in 44 shared pathways according to Metascape and 17 shared pathways according to DAVID. PPI analysis yielded 3 shared communities between the two disorders with enrichment in fibroblast signaling, ossification, and cardiac chamber development. CONCLUSIONS: The shared biology between IHH and CS was significantly greater than what was previously appreciated. Shared pathways of the two gene sets point toward the neural crest origin of subpopulations of the GnRH neuron and cranial suture osteoblast as a possible foundation for this shared biology, as well as the migratory nature of these two cells and the role that many genes in both gene sets play in cellular motility. Several CS genes emerge as candidates for IHH and must be individually evaluated. Functional studies should be used to confirm and further unravel the underlying mechanisms for the biological overlap between these two diseases. This study may provide a model for preemptive in silico work prior to more expensive in vitro or in vivo studies of pleiotropy.

Metopic synostosis is a condition in which the metopic suture of the human cranium fuses prematurely and may be related to poor behavioral inhibition leading to behaviors commonly associated with Attention-Deficit Hyperactivity Disorder (ADHD). The purpose of this project was to examine the behavior patterns among children with a history of metopic synostosis. It was hypothesized that children with a history of metopic synostosis would exhibit many of the same behavioral patterns associated with ADHD. It was also hypothesized that children with a history of simple synostosis not involving the metopic suture would not evidence this type of behavioral pattern. In order to test these hypotheses, the behavior of three groups of children was compared including (1) children who had a history of metopic synostosis (M= 7.63 years, SD = 1.92 years), (2) children who had a history of simple craniosynostosis not involving the metopic suture (M= 7.54 years, SD = 1.88 years), and (3) a group of children diagnosed with ADHD (M=7.78 year, SD = 1.87 years). It was found using the Home and School versions of the Attention Deficit Disorders Evaluation Scale (ADDES) that children with a history of metopic synostosis demonstrate significantly more behavioral disturbances than children with a history of simple craniosynostosis not involving the metopic suture. Using the BASC Teacher Rating Form it was found that children with a history of metopic synostosis have a behavior pattern similar to children diagnosed with ADHD and a dissimilar behavior pattern compared to children who have a history of craniosynostosis not involving the metopic suture. Using the BASC Parent Rating Form it was found that children with a history of metopic synostosis have a behavior pattern dissimilar to children diagnosed with ADHD and a dissimilar behavior pattern compared to children who have a history of craniosynostosis not involving the metopic suture.

INTRODUÇÃO: A educação neurocirúrgica requer muitos anos de treinamento prático e supervisionado. O desenvolvimento de plataformas de simulação cirúrgica é, portanto, essencial para reduzir o risco de erros intraoperatórios potencialmente graves decorrentes da inexperiência. Este estudo considera o treinamento cirúrgico para tratamento de hidrocefalia e cranioestenose. OBJETIVOS: Propor uma nova ferramenta para a educação neurocirúrgica, associando à simulação virtual e realística (realidade mista), para a correção da cranioestenose (tipo escafocefalia) e treinamento neuroendoscópico. MÉTODOS: Os simuladores físicos foram confeccionados com um silicone emborrachado termorretrátil e termossensível. Para validar os modelos de neuroendoscopia e cranioestenose, cirurgiões experientes participaram deste estudo usando vídeos de reconstrução tridimensional desenvolvidos pelo programa 3DS Max. Questionários sobre o papel dos simuladores virtuais e realísticos foram aplicados aos neurocirurgiões em relação à aplicabilidade da simulação de realidade mista para ambos os treinamentos cirúrgicos. O modelo virtual craniano foi criado com a obtenção de imagens no formato DICOM. Esta informação foi então processada usando um algoritmo de computação para gerar um biomodelo tridimensional em resina. O modelo e suas possibilidades de treinamento também foram avaliados qualitativamente por uma equipe de neurocirurgiões. Posteriormente, os especialistas avaliaram a aplicação da ferramenta para residentes em neurocirurgia. RESULTADOS: Os cirurgiões experientes consideraram a simulação mista como uma ferramenta potencial para o treinamento de novos residentes em neurocirurgia. Mais de 94% deles julgaram os simuladores adequados considerando aspectos como peso, posicionamento cirúrgico, dissecção por planos e reconstrução craniana. Em relação à experiência do modelo, cinco neurocirurgiões especialistas e 12 residentes de neurocirurgia participaram da avaliação. Todos consideraram a ferramenta positiva para o treinamento proposto. Os especialistas comentaram sobre quão interessante o modelo pode ser, instigando a compreensão das razões de cada etapa cirúrgica e de como atuar nelas. Os residentes apresentaram melhor clareza na visualização tridimensional, auxiliando indiretamente na compreensão da técnica cirúrgica. Além disso, eles notaram uma notável redução de erros em cada tentativa de montar o modelo. Os residentes consideraram ser um método de ensino cuja avaliação é objetiva e clara. CONCLUSÃO: Uma mistura de simulação física e virtual fornece previamente as habilidades psicomotoras e cognitivas necessárias, que são adquiridas apenas durante a aprendizagem prática cirúrgica. Finalmente, o quebra-cabeça pode ser uma importante ferramenta complementar, permitindo graus variados de imersão e realismo. Forneceu uma noção de realidade física, oferecendo informações dinâmicas simbólicas e geométricas, com rica visualização tridimensional. O uso de simuladores pode potencialmente melhorar e abreviar a curva de aprendizado dos cirurgiões / that requires many years of supervised hands-on training. The development of surgical simulation platforms is therefore essential to reducing the risk of potentially serious intraoperative errors arising from inexperience. This study considers the surgical training for hydrocephalus and craniosysnostosis treatment. OBJECTIVES:To propose a new tool for neurosurgical education, associating virtual and realistic simulation (mixed reality), for craniosynostosis correction (scaphocephaly type) and neuroendoscopic training. In addition, we sought to develop a \"puzzle\" to simulate the scaphocephaly surgical correction using Renier\"s \"H\" technique and to evaluate the learning impact for neurosurgery residents. METHODS: Physical simulators were made with a synthetic thermo-retractile and thermosensible silicone rubber. In order to validate the neuroendoscopy and craniosynostosis models, experienced surgeons participated in this study using tridimensional reconstruction videos developed by 3DS Max program. Questionnaires regarding the role of virtual and realistic simulators were applied to experienced neurosurgeons regarding the applicability of the mixed reality simulation for both surgery training. The puzzle cranial model was created by obtaining images through a multi slice CT scan DICOM format. This information was then processed using a computing algorithm to generate a three-dimensional biomodel in resine. The puzzle and its training possibilities were also evaluated qualitatively by a team of expert neurosurgeons. Subsequently the experts evaluated the application of the tool for residents in neurosurgery and the residents also evaluated the experience. RESULTS: The experienced surgeons considered the mixed reality simulation as a potential tool for training new residents in neurosurgery. More than 94% found the simulators appropriate considering aspects such as weight, surgical positioning, dissection by planes, and cranial reconstruction. Regarding the puzzle experience, five experts neurosurgeons and 12 neurosurgery residents participated in the evaluation. All considered the tool positive for the proposed training. The experts have commented on how interesting the model may be by instigating the understanding of the reasons for each surgical step and how to act in them. Residents presented better clarity in the three-dimensional visualization of the step by step, indirectly aiding in the understanding of the surgical technique. In addition, they noted a notable reduction of errors with each attempt to assemble the puzzle. Residents considered it to be a teaching method that makes assessment objective and clear. CONCLUSION: A mixture of physical and virtual simulation provide the required psychomotor and cognitive skills previously acquired only during practical surgical apprenticeship. Finally, puzzle in cranial shape may be an important complementary tool, allowing varying degrees of immersion and realism. It provided a notion of physical reality, offering symbolic, geometric and dynamic information, with rich tridimensional visualization. The simulators use may safely improve and abbreviate the surgeons learning curve

A expansão craniana com o uso de molas tem demonstrado eficácia no tratamento das anormalidades craniofaciais, tais como as craniossinostoses. A ação expansora exercida pelas molas tem sido observada tanto quando colocadas entre as margens parietais dos ossos do crânio, como quando lateralmente à sutura sagital, principalmente nas escafocefalias. No presente estudo foi criado um modelo experimental com coelhos, e feita uma avaliação descritiva do comportamento da calota craniana e das suturas sob ação de molas. Foram utilizados 13 coelhos Nova Zelândia com quatro semanas de vida, divididos em quatro grupos: grupo I, foram implantados no crânio marcadores de amálgama para controle; no grupo II, marcadores de amálgama e osteotomia da sutura sagital; no grupo III, marcadores de amálgama, osteotomia da sutura sagital e colocação de uma mola expansora na região interparietal e, no grupo IV, marcadores de amálgama, craniotomia parassagital linear com colocação da mola. Os animais foram sacrificados com duas, quatro, oito e doze semanas. Foi realizado controle radiológico com avaliação do afastamento dos marcadores de amálgama, da variação dos ângulos cefalométricos e das medidas da base do crânio, bem como um estudo histopatológico da região de colocação das molas. Nos grupos com o uso de molas a separação dos bordos da craniotomia foi maior do que naqueles sem a utilização de mola. Houve ossificação em todos os grupos, com maior rapidez no grupo II. O crescimento ósseo deu-se a partir dos bordos e da profundidade. Não foram observadas diferenças significativas no padrão histopatológico da regeneração óssea entre os grupos com colocação de mola na região interparietal e parassagital. O modelo experimental com coelhos se mostrou adequado às análises propostas pelo estudo. Concluiu-se que houve osteogênese por distração nos grupos III e IV e que apresentaram uma expansão craniana semelhantes. / Spring-mediated skull expansion has proven to be effective in the treatment of craniofacial abnormalities, such as craniosynostosis. The use of springs in cranial expansion has been studied both in the sagittal and in parasagittal regions, especially in scaphocephaly. A rabbit model was used in the present study to analyze the effects of springs on the cranial vault and sutures. Thirteen 4-week-old New Zealand rabbits were used and divided into 4 groups: group I, amalgam markers were used as control; in group II, amalgam markers and osteotomy of the sagittal suture; in group III, amalgam markers and osteotomy of the sagittal suture with implant of an expansible spring in the interparietal region and in group IV, amalgam markers and linear parasagittal craniectomy with springs. Animals were sacrificed after 2, 4 and 12 weeks. Radiological control with assessment of the amalgam markers, variation of cephalometric angles and cranial base measurements, as well as the histopathological analysis of the spring implant area were carried out. In the groups using springs distraction of the craniectomy borders was greater than in those that did not use springs. Ossification was observed in all of the groups and was faster in group II. Bone growth started from the borders and depth. There were no significant differences in the histopathological pattern of bone regeneration between the groups with spring implant in the interparietal and parasagittal region. The rabbit model proved to be adequate for the analysis proposed by the study. It was concluded that there was osteogenesis caused by distraction in groups III and IV, with similar skull expansion rates.