Background: Photoageing is due to the cumulative effects of sun exposure superimposed on chronological cutaneous ageing. Clinically, amongst Fitzpatrick skin types I-IV, it is thought that two main phenotypes of facial photoageing may exist: atrophic smooth telangiectactic skin (AP) and hypertrophic coarse wrinkled skin (HP). AP is more prone to the development of non-melanoma skin cancers (NMSC). Aim: To investigate the morphological and histological differences in photoexposed facial skin and photoprotected buttock skin from prototypic subjects with atrophic skin and hypertrophic phenotypes. Patients and Methods: Subjects with atrophic and hypertrophic skin were pre-selected based on their phenotype from the general population (n=40; n=20, hypertrophic phenotype, 10 males, 10 females; n=20, atrophic phenotype, 10 males, 10 females). All subjects had a 4mm punch biopsy taken from their UV exposed facial skin (cheek) and a 6mm punch biopsy taken from their UV-protected buttock skin. All selected participants were: ex- or non-smokers, had no history of inflammatory skin disease, and aged > 50 years (mean ± SE); [AP (78.7y ±2.02) and HP (74.6y ±2.08)]. Staining for elastic fibres, fibrillin-rich microfibrils (FRMs), collagen VII and Von Willebrand Factor (vWF) as well as morphometric measurements including dermal-epidermal convolution and epidermal thickness were performed. Demographic data and VISIA® photoassessments were additionally compiled. Analysis using ImageJ software and SPSS (Statistics 20; IBM) was performed. Results: We found that AP epidermis was thicker than HP (p < 0.0001) but there were no significant differences in dermal-epidermal junction (DEJ) convolution between phenotypes (p > 0.05). The percentage of dermis occupied by mature elastin fibres was significantly greater in HP than AP (p < 0.0001), but the dermis of HP was less enriched in fibrillin-rich microfibrils than AP (p < 0.05). AP was found to be collagen VII-poor compared to HP (p < 0.05) but, as expected, was more vascular with a greater number of blood vessels (p < 0.001 & p < 0.0001, respectively). No differences were found in any of these biomarkers in sun-protected buttock skin obtained from the same patients. Conclusion: This is a novel, exploratory study which demonstrates that the stroma in AP facial skin is characterised by less solar elastosis and collagen VII expression and more fibrillin-rich microfibrils, increased vascularisation compared to the HP phenotype. HP and AP appear to be distinct clinical and histological entities.

No description available.

No description available.

Atrophic non-union is a major complication following fracture of a bone. It represents a biological failure of the fracture healing process and occurs in 5-10% of cases. A number of factors predispose to atrophic non-union including high energy injuries, open fractures, diabetes, and smoking. Atrophic non-unions cause immense patient morbidity and consume large amount of health care resources. Bone grafts taken from the iliac crest contain biologic components required for fracture healing and are considered as the gold standard treatment of aseptic atrophic non-union. However, harvesting bone grafts from the iliac crest is associated with significant patient morbidity which can reduce quality of life. Mesenchymal stem cells (MSCs) have the ability to proliferate and undergo multilineage differentiation. The emergence of MSC therapy provides an alternative strategy for treating impaired fracture healing. MSCs contribute to normal fracture healing both directly as bone progenitor cells and indirectly as mediator secreting cells. Although a number of studies have shown that MSCs can promote bone regeneration in small animal fresh critical size defects, this is not analogous to most clinical aseptic atrophic non-unions which do not have a significant bone gap. There remains therefore a clinical need for an appropriate strategy for using stem cells in atrophic non-unions. Thus, the aim of this study aim was to develop a clinically relevant strategy to promote fracture healing in an atrophic non-union model using the percutaneous injection of MSCs as a minimally invasive technique. An atrophic non-union model was established and validated. A small (1 mm) non-critical size defect was created at the mid shaft tibia and the fracture site was stabilised using an external fixator. Atrophic non-union was induced by stripping the periosteum for one bone diameter either side of the osteotomy site and curettage of the intramedullary canal over the same distance. The procedure reliably created an atrophic non-union. Fracture healing was evaluated using (1) serial radiography, (2) micro-computed tomography, (3) histomorphology and (5) biomechanical testing. Fracture scoring systems including the radiographic union scale in tibia (RUST) and the Lane & Sandhu score were validated in a preclinical model. A simple sample preparation technique for evaluating bone mechanical properties was developed and used to assess the stiffness and strength of the fracture repair. Percutaneous injection of MSCs locally into the fracture site in the early ‘post-injury’ period at three weeks after induction of atrophic non-union was found to improve the fracture healing process significantly (83% of cases), while MSCs implantation in the late ‘post-injury’ period at eight weeks after induction of atrophic non-union showed no significant improvement of fracture healing (20% of cases). Percutaneous local implantation of MSCs rescued the fracture healing process in cases destined to progress to atrophic non-union. In clinical practice, there may be an advantage using MSCs from a universal donor as the processes of MSC isolation and preparation are expensive and time consuming. To investigate the feasibility of using non-autologous cells, the atrophic non-union was used to determine the bone regenerative potential of using xenogeneic donor hMSCs in an atrophic non-union. The results demonstrated that the therapeutic effect of using hMSCs in a xenogeneic manner to promote fracture healing in the rat atrophic non-union model was comparable with rMSCs (88% of cases in both hMSCs and rMSCs) and there were neither significant clinical adverse effects nor adverse immune responses with the xenogeneic transplantation. However, MSCs did not persist at the fracture following injection. Perivascular stem cells (PSCs) taken from adipose tissue, which is an expendable source, have advantages over conventional MSCs as they are a defined and homogenous population and can be used without culture expansion. The administration of PSC using percutaneous injection improved the fracture healing process in atrophic non-union (60% of cases). This suggested that PSCs may present an appropriate choice for use in cell therapies to promote fracture healing in atrophic non-union. The results from this thesis can be applied to the development of a clinically relevant strategy using MSCs as a minimally invasive technique to promote fracture healing in atrophic non-union, in particular (1) the effectiveness of a cell therapy is likely to be highly dependent of the timing of injection relative to the stage of fracture healing, (2) hMSCs were as effective as rMSCs in promoting fracture healing, suggesting that it may be feasible to use an allogeneic strategy in humans, (3) the injected MSCs were not detectable even in case of successful repair, suggesting that they may act through a paracrine effect and (4) PSCs isolated from adipose tissue contributed to fracture healing in the atrophic non-union model, suggesting that adipose tissues can be used as an alternative cell sources for bone repair.

A não-união de fratura é uma complicação relativamente comum em ortopedia humana e veterinária. Dentre os tipos de não-união, a atrófica costuma ser a mais difícil de tratar. Atualmente, o tratamento amplamente utilizado para esses casos é invasivo. Buscando alternativas, o presente estudo objetivou observar se o decanoato de nandrolona interfere positivamente no incremento de regeneração de não-união de fratura óssea com déficit vascular induzida experimentalmente em rato. Foram utilizados 10 ratos adultos da linhagem Wistar (Rattus norvegicus), divididos em 2 grupos (grupo controle - GC e grupo tratado - GNan). Protocolos cirúrgicos foram desenvolvidos a fim de promover fratura na diáfise do fêmur esquerdo com indução de déficit vascular por remoção do periósteo e endósteo e isolamento do foco de fratura com artefato de látex. Em seguida ao estabelecimento do quadro de não-união de fratura nos dois grupos de estudo, foi administrado 1,5mg/kg de decanoato de nandrolona IM, uma vez por semana, durante 4 semanas no GNan. A verificação do perfil morfológico do tratamento foi realizada pelo exames radiológicos periódicos, exame anatomopatológico, microscopia eletrônica de varredura, microtomografia computadorizada e microscopia óptica. Os resultados mostraram que o protocolo de não-união de fratura desenvolvido foi eficiente para estudos qualitativos e quantitativos de crescimento ósseo. Adicionalmente, foi observado que o decanoato de nandrolona promoveu incremento significativo de regeneração óssea em não-união de fratura com déficit vascular por aumento da atividade osteoblástica e redução da atividade osteoclástica no GNan. Houve aumento de massa óssea na cabeça femoral e diferentes regiões da diáfise femoral. As análises de percentual de colágeno não revelaram diferenças significativas entre GC e GNan, portanto, a qualidade óssea entre os grupos é semelhante. Dada viabilidade econômica do fármaco, é sugerido ensaios mais avançados que comprovem o potencial terapêutico do decanoato de nandrolona no tratamento de não-união de fratura atrófica em pacientes humanos e veterinários / The nonunion fracture is a relatively frequent complication in both human and veterinary medicine. Among their types, the atrophic nonunion fracture is usually the most difficult to treat and the elective treatment is surgery. In order to search for alternative therapeutic approach, the present study aimed to analyze the morphological changes induced by the use of nandrolone decanoate in experimental nonunion fracture with vascular deficit in the rat model. Ten adult Wistar rats (Rattus norvegicus) were divided into two groups, control (GC) and nandrolone decanoate (GNan). Surgical protocols were developed to promote fracture nonunion in the left femur diaphysis with vascular deficit by removing the periosteum and endosteum and isolating the fracture site using a latex artifact. After the establishment of the nonunion fracture, the GNan was treated with nandrolone decanoate (1.5mg/kg IM, once a week, during 4 weeks). Periodical radiological examinations were performed. In addition, anatomopathological evaluation, scanning electron microscopy, computed micro-tomography and optical microscopy techniques were performed. The results showed that the surgical protocols to establish the nonunion fracture were efficient and allowed qualitative and quantitative evaluation of bone growth. Besides, the nandrolone decanoate promoted the bone regeneration at the nonunion fracture site by raising the osteblastic activity and reducing the osteclastic activity. The percentage of collagen analysis did not reveal significant differences between GC and GNan. This guarantees some quality for the regenerated bone. Due to the economical viability of the use of nandrolone decanoate use, new advanced studies are recommended to prove the therapeutic potential of that anabolic steroid for the treatment of atrophic nonunion fracture in humans and other animals

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2006. / Härtill 4 uppsatser.

A não-união de fratura é uma complicação relativamente comum em ortopedia humana e veterinária. Dentre os tipos de não-união, a atrófica costuma ser a mais difícil de tratar. Atualmente, o tratamento amplamente utilizado para esses casos é invasivo. Buscando alternativas, o presente estudo objetivou observar se o decanoato de nandrolona interfere positivamente no incremento de regeneração de não-união de fratura óssea com déficit vascular induzida experimentalmente em rato. Foram utilizados 10 ratos adultos da linhagem Wistar (Rattus norvegicus), divididos em 2 grupos (grupo controle - GC e grupo tratado - GNan). Protocolos cirúrgicos foram desenvolvidos a fim de promover fratura na diáfise do fêmur esquerdo com indução de déficit vascular por remoção do periósteo e endósteo e isolamento do foco de fratura com artefato de látex. Em seguida ao estabelecimento do quadro de não-união de fratura nos dois grupos de estudo, foi administrado 1,5mg/kg de decanoato de nandrolona IM, uma vez por semana, durante 4 semanas no GNan. A verificação do perfil morfológico do tratamento foi realizada pelo exames radiológicos periódicos, exame anatomopatológico, microscopia eletrônica de varredura, microtomografia computadorizada e microscopia óptica. Os resultados mostraram que o protocolo de não-união de fratura desenvolvido foi eficiente para estudos qualitativos e quantitativos de crescimento ósseo. Adicionalmente, foi observado que o decanoato de nandrolona promoveu incremento significativo de regeneração óssea em não-união de fratura com déficit vascular por aumento da atividade osteoblástica e redução da atividade osteoclástica no GNan. Houve aumento de massa óssea na cabeça femoral e diferentes regiões da diáfise femoral. As análises de percentual de colágeno não revelaram diferenças significativas entre GC e GNan, portanto, a qualidade óssea entre os grupos é semelhante. Dada viabilidade econômica do fármaco, é sugerido ensaios mais avançados que comprovem o potencial terapêutico do decanoato de nandrolona no tratamento de não-união de fratura atrófica em pacientes humanos e veterinários / The nonunion fracture is a relatively frequent complication in both human and veterinary medicine. Among their types, the atrophic nonunion fracture is usually the most difficult to treat and the elective treatment is surgery. In order to search for alternative therapeutic approach, the present study aimed to analyze the morphological changes induced by the use of nandrolone decanoate in experimental nonunion fracture with vascular deficit in the rat model. Ten adult Wistar rats (Rattus norvegicus) were divided into two groups, control (GC) and nandrolone decanoate (GNan). Surgical protocols were developed to promote fracture nonunion in the left femur diaphysis with vascular deficit by removing the periosteum and endosteum and isolating the fracture site using a latex artifact. After the establishment of the nonunion fracture, the GNan was treated with nandrolone decanoate (1.5mg/kg IM, once a week, during 4 weeks). Periodical radiological examinations were performed. In addition, anatomopathological evaluation, scanning electron microscopy, computed micro-tomography and optical microscopy techniques were performed. The results showed that the surgical protocols to establish the nonunion fracture were efficient and allowed qualitative and quantitative evaluation of bone growth. Besides, the nandrolone decanoate promoted the bone regeneration at the nonunion fracture site by raising the osteblastic activity and reducing the osteclastic activity. The percentage of collagen analysis did not reveal significant differences between GC and GNan. This guarantees some quality for the regenerated bone. Due to the economical viability of the use of nandrolone decanoate use, new advanced studies are recommended to prove the therapeutic potential of that anabolic steroid for the treatment of atrophic nonunion fracture in humans and other animals

Este estudo tem como objetivo apresentar uma análise retrospectiva de dados contidos em prontuários de atendimento, sobre a evolução clínica de 129 implantes zigomáticos colocados no seio maxilar de 37 pacientes com maxila desdentada severamente reabsorvida (total ou parcialmente), os quais foram reabilitados através da instalação de implantes zigomáticos pela equipe de Cirurgia e Traumatologia Buco-Maxilo-Facial da Faculdade de Odontologia de Ribeirão Preto (FROP-USP), durante o período março/2007 à novembro/2014. Todos os pacientes incluídos no estudo foram tratados usando o mesmo protocolo cirúrgico, técnica ´´sinus slot´´ modificado por Stella. A análise foi direcionada a registro de dados relativos as seguintes variáveis: gênero, idade, raça, história médica, etiologia, vícios, grau de atrofia óssea, tipo e tamanho dos implantes zigomáticos, número de implantes colocados, reabilitação protética, a taxa de sobrevivência e de sucesso dos implantes, além das complicações. Os indivíduos foram acompanhados por meio de exames clínicos e de tomográficos padronizados. O critério de inclusão dos prontuários na amostra foram de pacientes submetidos a esse tipo de tratamento, com preenchimento completo de informações e de possuírem o Termo de Consentimento Livre e Esclarecido. Os dados coletados por um único examinador foram transportados para uma planilha eletrônica utilizando o programa Microsoft Excel, sendo realizada neste momento uma análise descritiva dos resultados. Trinta e sete pacientes consecutivos (25 mulheres, 12 homens; média de idade de 55,64 anos [variação: 40-77 anos]) foram tratados. Todos estavam em necessidade de reabilitação bucal e tinham atrofia maxilar severa com indicação para a colocação de implantes zigomáticos. Cento e vinte e nove implantes zigomáticos foram colocados nesses 37 pacientes. Dois dos 129 implantes falharam, resultando em uma taxa de sucesso de 98,44%, com esses dados de acompanhamento. Sinusite do seio maxilar foi a ocorrência mais comum (21,62%) entre as complicações encontradas. No entanto, entre os implantes que falharam, nenhum foi relacionado com sinusite ou fumo. Concluímos que tratamento com implantes zigomáticos representa uma opção previsível para reabilitação da maxila atrófica desdentada. No entanto, mais estudos são necessários para se relacionar diretamente esses implantes com a sinusite, que apresenta uma elevada prevalência nestes casos. / This study aims to present a retrospective analysis of data contained in patient records on the clinical course of 129 zygomatic implants placed in the maxillary sinus of 37 patients with severely resorbed edentulous maxilla (fully or partially), which were rehabilitated by installing of zygomatic implants by staff of Surgery and Traumatology Oral and Maxillofacial Ribeirão Preto Dental School (FROP-USP), during the period from March/2007 to November/2014. All patients included in the study were treated using the same surgical protocol, \'\'sinus slot\'\' modified by Stella technique. The analysis was aimed at data record the following variables: gender, age, race, medical history, etiology, addictions, degree of bone atrophy, type and size of zygomatic implants, number of placed implants, prosthetic rehabilitation, the survival rate and success of the implant, in addition to complications. The subjects were followed through clinical and standardized CT. The criterion for inclusion of the records in the sample were patients undergoing this type of treatment, with complete filling of information and possess the Informed Consent and Informed. The data collected by a single examiner were transported to a spreadsheet using Microsoft Excel program, being carried out at present a descriptive analysis of the results. Thirty-seven consecutive patients (25 women, 12 men; mean age of 55.64 years [range, 40-77 years]) were treated. All were in need of oral rehabilitation and had severe jaw atrophy indicated for the placement of zygomatic implants. One hundred and twenty-nine zygomatic implants were placed in these 37 patients. Two of the 129 implants fail, resulting in a success rate of 98.44%, with these tracking data. Maxillary sinus sinusitis was the most common event (21.62%) among the complications found. However, between implants that have failed, none has been associated with sinusitis or smoke. We conclude that treatment with zygomatic implants is a predictable option for rehabilitation of edentulous atrophic maxilla. However, more studies are needed to relate directly with these implants sinusitis, which has a high prevalence in these cases.

Submitted by Tatiane Pereira Scarpelli (tati.scarpelli@gmail.com) on 2018-08-15T01:03:56Z No. of bitstreams: 1 Tatiane- dissertação final.pdf: 1984978 bytes, checksum: 95d87d58bd4bea79691e4ec03d530a18 (MD5) / Approved for entry into archive by Elza Mitiko Sato null (elzasato@ibilce.unesp.br) on 2018-08-15T12:42:09Z (GMT) No. of bitstreams: 1 scarpelli_tp_me_sjrp.pdf: 1984978 bytes, checksum: 95d87d58bd4bea79691e4ec03d530a18 (MD5) / Made available in DSpace on 2018-08-15T12:42:09Z (GMT). No. of bitstreams: 1 scarpelli_tp_me_sjrp.pdf: 1984978 bytes, checksum: 95d87d58bd4bea79691e4ec03d530a18 (MD5) Previous issue date: 2018-08-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O consumo excessivo de lipídios na dieta constitui um problema na alimentação da sociedade atual, contribuindo para o desenvolvimento de doenças e de cânceres como o de mama, de próstata e de cólon. Se tratando da próstata, os lipídios podem ter ação direta, ou por mediadores celulares deles derivados e desequilibrar os níveis de esteroides sexuais. Contudo, alguns componentes dietéticos exercem papel benéfico para a saúde prostática ou mesmo propriedades terapêuticas, como a curcumina. Existe, portanto, interesse crescente na ação da curcumina sobre a próstata, e seus análogos sintéticos vem sendo testados para aplicação no tratamento de doenças prostáticas. Sabendo-se que componentes da dieta materna podem afetar a próstata masculina permanentemente, por programação do desenvolvimento, este estudo avaliou as consequências da dieta materna enriquecida com lipídios saturados da banha de porco, durante a gestação e lactação de ratos Wistar, associada ou não à suplementação alimentar com curcumina, além da ingestão do óleo de milho comercial, sobre a histofisiologia da próstata ventral da prole na idade adulta. Ratos Wistar foram divididos em cinco grupos (n=12 por grupo; 12 semanas de idade), segundo o regime alimentar ao qual as mães foram submetidas da 8ª sem. de idade até o desmame dos filhotes: C - dieta padrão; O- dieta padrão e óleo de milho (100µL em dias alternados, via gavagem); Cm - dieta padrão e óleo de milho contendo curcumina (100mg/kg de peso corporal, em dias alternados, via gavagem); L- dieta enriquecida com banha de porco (31% de banha de porco) e LCm - dieta enriquecida com banha de porco e óleo de milho/curcumina. Após eutanásia dos animais e realizada coleta dos materiais biológicos, como a próstata ventral e o sangue, realizaram-se análises das quais se obteve aumento nos depósitos de gorduras epididimal e visceral e, consequentemente, aumento no índice de adiposidade dos grupos L e O. Os animais dos grupos O e LCm tiveram aumento nos níveis de triglicerídeos e o grupo O apresentou aumento no nível de colesterol HDL. Os animais de O, L e LCm apresentaram atrofia epitelial, evidenciada tanto pela análise da frequência de ácinos atróficos, pela altura do epitélio e pela diminuição da frequência relativa do epitélio acinar. Ainda, os animais do grupo L apresentaram aumento da frequência relativa do compartimento luminal e de fibras colágenas. Não houve alterações nos níveis de proliferação celular. A expressão de receptores de andrógenos (AR) no epitélio foi maior no grupo L e um pouco menor para os grupos O e LCm. A incidência (número de animais acometidos/número total de animais) de focos inflamatórios aumentou nos grupos O e L (C- 29%; O – 40%; L – 78%) e foi reduzida pelo consumo de curcumina (Cm- 8%; LCm- 38%). Os dados obtidos indicam que, as dietas maternas enriquecidas com lipídios causam respostas na morfologia e na fisiologia da próstata ventral, em diferentes níveis. A banha pareceu alterar a estrutura e a expressão de AR de maneira acentuada, além de propiciar inflamação na glândula, enquanto o óleo de milho altera em menor grau. Além disso, a curcumina sozinha responde positivamente na próstata. / Excessive consumption of lipids in the diet is a problem in the feeding of current society, contributing to the development of diseases and cancers such as breast, prostate and colon. Lipids can have direct action on the prostate gland, or by cellular mediators derived from them and unbalance levels of sexual steroids. However, some dietary components play a beneficial role in prostate health or even therapeutic properties, such as curcumin. There is, therefore, growing interest in the action of curcumin on the prostate, and its synthetic analogues have been tested for application in the treatment of prostatic diseases. Knowing that components of the maternal diet can permanently affect the male prostate gland by developmental programming, this study evaluated the consequences of the maternal diet enriched with lard saturated lipids during gestation and lactation of Wistar rats, associated or not with dietary supplementation with curcumin, in addition to the commercial corn oil intake, on the histophysiology of the ventral prostate of the offspring in adulthood. Wistar rats were divided into five groups (n = 12 per group, 12 weeks old), according to the diet to which the mothers were submitted from the 8th week of age until the weaning of the pups: C - standard diet; O- standard diet and corn oil (100 μL on alternate days, via gavage); Cm - standard diet and corn oil containing curcumin (100mg / kg body weight, every other day, via gavage); L - diet enriched with lard (31% of lard) and LCm - diet enriched with lard and corn oil / curcumina. After the euthanasia of the animals and the collection of biological materials, such as the ventral prostate and blood, analyzes were carried out, which resulted in an increase in the deposits of epididimal and visceral fat and, consequently, an increase in the adiposity index of the L and O groups. The animals in the O and LCm groups had an increase in triglyceride levels and the O group had an increase in the level of HDL cholesterol. The O, L and LCm animals presented epithelial atrophy, evidenced both by the analysis of the atrophic acini frequency, by the height of the epithelium and by the decrease of the relative frequency of the acinar epithelium. Still, the animals in the L group presented increased relative frequency of the luminal compartment and collagen fibers. There were no changes in the levels of cell proliferation. The expression of receptor androgen (AR) in the epithelium was higher in the L group and somewhat lower in the O and LCm groups. The incidence (number of affected animals / total number of animals) of inflammatory foci increased in the O and L groups (C - 29%, O - 40%, L - 78%) and was reduced by the consumption of curcumin (C - 8% (LC-38%). The data obtained indicate that maternal diets enriched with lipids cause responses in the morphology and physiology of the ventral prostate at different levels. The lard appeared to alter the structure and expression of AR very markedly, in addition to providing inflammation in the gland, while the corn oil changes to a lesser degree. In addition, curcumin alone responds positively in the prostate.

Made available in DSpace on 2014-06-11T19:35:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-03-27Bitstream added on 2014-06-13T21:07:05Z : No. of bitstreams: 1 almeida_eo_dr_araca.pdf: 891355 bytes, checksum: 4a430507a208f5a8321332c71108ee4c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Proposição. O objetivo deste estudo foi avaliar o comportamento biomecânico de prótese fixa implanto-suportada com implantes longos angulados e implantes curtos retos posicionados na região mais posterior de maxila moderadamente atrófica. As hipóteses foram de que a presença do implante distal longo inclinado (all-on-four) e do implante distal curto reto (all-on-six) resultariam em maior (hipótese-1) e menor (hipótese-2) tensão no osso maxilar quando comparada a presença dos implantes distais longos verticais (all-on-four). Materiais e Métodos. O modelo 3D foi confeccionado baseado na tomografia de um paciente com maxila atrófica e na micro-tomografia dos implantes Nobel Biocare. As diferentes configurações foram: M4R, quatro implantes verticais anteriores (4X11.5 X 4X13mm); M4I, dois implantes verticais mesiais (4X11.5mm) e dois implantes inclinados distais (45°) (4X13mm); M6R, quatro implantes verticais anteriores (4X11.5 X 4X13mm) + dois implantes curtos verticais posteriores (5X7mm). Foram aplicados carregamentos bilaterais simultâneos (150N) axial (C1) e obliquo (C2) na região de cantilever posterior. Foi adotada a Tensão Principal Máxima (σmax) para avaliação da tensão óssea e a tensão Equivalente de von Mises (σvM) para avaliação dos implantes. Resultados. Independente da direção do carregamento, a σmax foi maior no M4I (C1 0,87 e C2 0,85 GPa), seguido pelo M6R (C1 0,71 e C2 0,53 GPa) e M4R (C1 0,59 e C2 0,44 GPa). Os implantes mais próximos da área de carregamento apresentaram os maiores valores de tensão no planejamento M6R, seguido pelo M4I e M4R. Conclusões. As hipóteses 1 e 2 foram respectivamente aceita e parcialmente negada, uma vez que a presença do implante distal longo inclinado e do... / Purpose. This study compared the biomechanical behavior of tilted long implant and vertical short implants to support fixed prosthesis in an atrophic maxilla. The hypotheses were that the presence of distal tilted (all-on-four) and distal short implants (all-on-six) would respectively result in higher (Hypotheses 1) and lower (Hypotheses) stresses in the maxillary bone in comparison to the presence of vertical implants (all-on-four). Materials and Methods. The maxilla model was built based on a tomographic image of the patient. Implant models were based on micro-CT imaging of implants. The different configurations considered were: M4S, four vertical anterior implants; M4T, two mesial vertical implants and two distal tilted (45°) implants in the anterior region of the maxilla; and M6S, four vertical anterior implants and two vertical posterior implants. Numerical simulation was carried out under bilateral 150N loads applied in the cantilever region in axial (L1) and oblique (45°) (L2) direction. Maximum principal stress (σmax) and von Mises stress (σvM) were utilized for bone and implant stresses assessments, respectively. Results. Regardless of loading direction, bone σmax was highest for the M4T (L1 0.87 and L2 0.85 GPa), followed by M6S (L1 0.71 and L2 0.53 GPa) and M4S (L1 0.59 and L2 0.44 GPa). Implants in proximity of the loading area presented highest stress values in the M6S configuration, followed by the M4T and then the M4S. Conclusions. The hypotheses of the present study were that the presence of distal tilted (all-on-four) and distal short implants (all-on-six) would respectively result in higher and lower stresses in the maxillary bone in comparison to the presence of vertical implants (all-on-four), were respectively accepted and... (Complete abstract click electronic access below)