Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The South African National Standard for the structural use of cold-formed steel (SANS 10162-2) provides capacity prediction models for screwed connections. Screwed connections are designed against shear failure of the screw(s), section tear-out, net section failure and tilt-andbearing failure. Previous studies (Rogers & Hancock, 1997) showed that the capacity is typically determined by the tilt-and-bearing type failure mode. The aim of this document is to report on the reliability of single screwed connections in cold-formed steel against this critical failure mode. Predicted nominal capacities depend on the ultimate tensile strength of the steel, the thickness of the connected plates and the diameter of the screw. Design capacities are obtained by multiplying the nominal capacities by a capacity reduction factor of 0.5, according to SANS 10162-2. Reliability is assessed by means of FORM analyses, taking uncertainty in the prediction model and variability of input parameters into account. Laboratory testing of 222 single screwed connections allowed to statistically describe the model factor, i.e. the ratio of actual tested- over unbiased predicted capacity. For each connection, the steel strength, plate thickness and screw diameter were measured, with the measured values used to predict capacity. This implies that the model factor accounts for uncertainty in the prediction model and experimental setup, while the variability of input parameters is separately accounted for through appropriate statistical modelling. Variability in the input parameters was described using appropriate statistical distributions from expert literature (Holicky, 2009:199; JCSS, 2000). For steel strength, the mean value and standard deviation were obtained from tensile tests, while mean values and standard deviations of the plate thickness and screw diameter were obtained from the above mentioned measurements. The experimental work and numerical analysis resulted in a model factor with a mean just exceeding unity and a small standard deviation. This suggests that the design code under consideration is able to accurately predict the nominal capacity of screwed connections. The FORM analysis resulted in computed reliability indexes significantly higher than the corresponding target values which suggest conservative and reliable design formulations. Die eksperimentele werk en numeriese analise het gelei tot 'n model faktor met 'n gemiddeld hoër as een en 'n klein standaardafwyking. Dit dui daarop aan dat die ontwerp-kode onder oorweging in staat is om die nominale kapasitiet van skroef verbindings akkuraat te voorspel. Die betroubaarheid analise het gelei tot betroubaarheidsindekse aansienlik hoër as die ooreenstemmende teiken waardes wat daarop dui dat die ontwerp formulerings betroubaar en hoogs konserwatief is. / AFRIKAANSE OPSOMMING: Die Suid-Afrikaanse Nasionale Standaard vir die strukturele gebruik van koud gevormde staal (SANS 10162-2) bied voorspellingsmodelle vir die kapasitiet van skroef verbindings. Skroef verbindings word ontwerp teen skroef faling, staal profiel faling, die uitskeer van skroewe en ook faling weens skroef kanteling. Vorige studies (Rogers & Hancock, 1997) het getoon dat die kapasiteit gewoonlik bepaal word deur die skroef-kantel falingsmodus. Die doel van hierdie navorsing is om verslag te doen oor die betroubaarheid van tipiese enkel skroef verbindings in koud gevormde staal strukture teen hierdie kritiese falingsmodus. Voorspelde nominale kapasiteite hang af van die treksterkte van die staal, die dikte van die verbonde profiele en die diameter van die skroef. Volgens die SANS 10162-2 word die ontwerp kapasiteit verkry deur die nominale kapasiteit met 'n kapasiteitsverminderingsfaktor van 0.5 te vermenigvuldig. Betroubaarheid word ontleed deur middel van ʼn eerste orde betroubaarheidsmetode analise, met die in ag neming van onsekerheid in die voorspellingsmodel en wisselvalligheid van die parameters. Laboratoriumtoetse van 222 enkel skroef verbindings het ʼn statistiese beskrywing van die model faktor toegelaat. Die model faktor is bereken as die verhouding tussen die getoetste kapasitiet en die voorspelde kapasitiet. Die staal sterkte, profiel dikte en skroef diameter is gemeet vir elke verbinding met die gemete waardes wat gebruik is om die kapasiteit te voorspel. Dit beteken dat die model faktor slegs onsekerhede in die voorspellingsmodel en van die eksperimentele opstelling in ag neem, terwyl die wisselvalligheid van die parameters afsonderlik in ag geneem word deur toepaslike statistiese modellering. Variasie in die parameters is beskryf met gepaste statistiese verdelings voorgestel deur verskeie literatuur (Holicky, 2009:199; JCSS, 2000). Aangaande die staal sterkte, is die gemiddelde waardes en standaardafwykings verkry deur standaard trek toetse terwyl die gemiddelde waardes en standaardafwykings van die plaat dikte en skroef diameter verkry is deur die bogenoemde metings.

O afrouxamento dos parafusos protéticos é descrito na literatura como uma das complicações mais frequentes das próteses sobre implantes. Durante sua confecção, os profissionais sentem necessidade de remover várias vezes as próteses e/ou componentes protéticos, soltando e re-apertando os parafusos repetidamente. O principal objetivo deste trabalho foi avaliar a variação do torque de remoção de parafusos de fixação de pilares protéticos a implantes osteointegráveis após sucessivos ciclos de parafusamento e desparafusamento. Outro objetivo foi avaliar a influência do hexágono da base do pilar no torque de remoção dos parafusos. Para isso, foram utilizados 20 implantes de plataforma regular com hexágono externo e 20 pilares protéticos sextavados, que foram parafusados aos implantes com um parafuso de titânio, aplicando-se a este um torque de 32Ncm, por meio de um torquímetro digital. Os conjuntos implante/pilar/parafuso foram divididos em dois grupos: (1) pilares cujo hexágono da base foram removidos e (2) pilares convencionais, com hexágono na base. Cada conjunto recebeu uma restauração provisória e foi submetido a ciclagem mecânica por 15 minutos. Depois, os parafusos foram removidos, medindo-se o torque de remoção. Esta sequência foi repetida dez vezes e então o parafuso foi trocado por outro sem uso, e mais um ciclo foi realizado. Uma análise de regressão linear demonstrou nos dois grupos uma queda do torque de remoção do parafuso ao longo dos repetidos ciclos de inserção/remoção. A comparação entre os coeficientes da regressão nos dois grupos não revelou diferença entre eles. Também não houve diferença entre as médias das 5 últimas repetições e o 11 ciclo, com o parafuso novo. Concluiu-se que (1) repetidos parafusamentos e desparafusamentos promoveram a diminuição progressiva do torque de remoção dos parafusos, (2) a troca do parafuso por outro sem uso após dez ciclos de inserção/remoção não aumentou sua resistência ao afrouxamento, e (3) a remoção do hexágono da base do pilar protético não exerceu nenhum efeito sobre o torque de remoção do parafuso. / Screw loosening is one of the most common problems of implant-retained prostheses. During their confection, dentists need to remove and re-install them several times, loosening and re-tightening the screws repeatedly. The first purpose of this study was to evaluate the effects of repeated insertion/removal cycles on the removal torque of retaining prosthetic screws. The second purpose was to evaluate the influence of the hexagon of the abutment on the removal torque. For that, 20 regular external hex implants were used and 20 hexagonal abutments were tightened to the implants with a titanium alloy screw, with an insertion torque of 32Ncm, given by a digital torque gauge. The implant/abutment/screw assemblies were divided into two groups: (1) abutments with no hexagon on the base and (2) abutments with an hexagon on the base. Each assembly received a provisional restoration and was submitted to mechanical loading cycles for 15 minutes. After this, the screws were removed and the removal torque measured. This sequence was repeated ten times and then, the screw was changed for a new one, and another cycle was done. Linear regression analysis was performed and showed that removal torque values tended to decrease as the number of insertion/removal cycles increased, for both groups. Comparisons of the slopes and the intercepts between the two groups showed no statistic difference between them. There was also no difference between the mean values of last 5 cycles and the 11th cycle. It was concluded that (1) repeated insertion/removal cycles promoted gradual reduction in removal torque of screws, (2) changing screw by a new one after ten insertion/removal cycles did not increase resistance to loosening, and (3) removal of the hexagon of the abutment base had no effect on the removal torque of the screw.

Abstract The economic growth of Taiwan was guided by small and medium enterprises; Especially Taiwan fastener industry acts an important role for Taiwan small and medium enterprises. As an old saying goes ¡§the young soldier sets up the great merit. ¡§ This is best way to describe Taiwan fastener industry. Taiwan fastener industry is playing an important part of National Development, but even government rulers ignore this. Unless you are part of Taiwan fastener industry, you can not understand that this industry is such respectable. It has been more 60 years since Taiwan launched into its name of fastener supply center. Mostly Taiwan fastener industry is small and medium enterprises. However these enterprises could not get much help from government or each other. They all fight alone. Many companies cannot survive when they meet difficulties and bottlenecks. Even companies want to help each other, integration are a big problem to them. This research is tried to discuss how Taiwan fastener industry to face China¡¦s Lower price competitive stratagem does. Author will all around discuss, analyzes and compare this topic¡§The strategic alliance will be applied between some companies of the fastener industry¡¨ to give to Taiwan fastener industry an all around competitive stratagem. Postgraduate student are working on this research not only to help running my own company but also as a Reference for Taiwan fastener industry.

Thesis (M.S.)--Mississippi State University. Department of Clinical Sciences, College of Veterinary Medicine. / Title from title screen. Includes bibliographical references.

The common profiled steel cladding systems used in Australia and its neighboring countries are made of very thin (0.42 mm) high strength steel (G550 with a minimum yield stress of 550 MPa) and are crest-fixed. However, these claddings often suffer from local pull-through failures at their screw connections during high wind events such as storms and cyclones. Past experience and researches have shown that the loss of steel roofs has often occurred due to local pull-through failures of their screw connections under uplift or suction loading. Loss of claddings always led to a progressive collapse of the entire building. This situation is continuing because of the lower priority given to the design of roof and wall cladding systems. At present, steel design codes do not provide guidelines for the design of crest-fixed steel roof or wall claddings. Past research has shown that European and American recommendations for steel claddings cannot be used for Australian crest-fixed cladding systems as they were developed mainly for valley-fixed claddings subjected to gravity loading instead of crest-fixed claddings subjected to wind uplift/suction loading. Therefore at present the design of thin steel cladding systems is based on laboratory tests and is expensive. These situations inhibit the innovative design and advances in the steel cladding industry. Since the local pull-through failures in the less ductile G550 steel claddings are initiated by transverse splitting at the fastener hole, analytical studies have not been able to determine the pull-through failure loads accurately. Therefore in the first stage of this research an appropriate fracture/splitting criterion was developed using a series of large scale and small scale experiments of crest-fixed steel claddings. A shell finite element model of crest-fixed steel cladding was then developed that included the new fracture/splitting criterion and advanced features such as hyperelastic material modelling, contact simulations, residual stresses and geometric imperfections. The improved finite element analyses were able to model the pull-through failures associated with splitting as evident from the comparison of their results with the corresponding full-scale experimental results. An extensive series of parametric studies considering the effects of material properties and geometric parameters of the two commonly used trapezoidal cladding profiles was undertaken using finite element analysis. Appropriate design formulae for the pull-through and dimpling failure load of trapezoidal profiles were then derived for optimization purposes and to simplify the current design method. This will then lead to modification and optimisation of cladding profiles to satisfy the requirements of both strength (safety during cyclones and storms) and economy. This thesis presents the details of large scale experimental studies undertaken and the results including the criterion for the splitting/fracture failure of high strength steel cladding systems. It describes the many advances made in the finite element modelling of crest-fixed steel cladding systems including the effects of localised pull-through and dimpling failures. Finally, it presents a simple design method for trapezoidal steel cladding systems under wind uplift or suction loading.

Thesis (M.S.)--Medical College of Ohio, 2005. / "In partial fulfillment of the requirements for the degree of Master of Science in Biomedical Sciences." Major advisor: Nabil Ebraheim. Includes abstract. Document formatted into pages: iii, 57 p. Title from title page of PDF document. Bibliography: pages 35-42,49-56.

Componentes de próteses e órteses humanas devem ser confortáveis, capazes de realizar as funções esperadas e, mais do que tudo, confiáveis. O foco deste trabalho é no desenvolvimento e aplicação de uma metodologia de análise de parafusos cirúrgicos. Para tanto foi desenvolvido um aparato mecânico, que consiste em um atuador de torque e um sistema de aquisição de dados. O atuador, composto por um motor elétrico acoplado a um redutor, aplica torque sobre o parafuso em teste, que o transfere a uma célula de carga e, assim, ao sistema de aquisição de dados. Parafusos canulados de aço inoxidável e corticais de titânio, de diferentes fabricantes, foram testados para torque de inserção e remoção, torque máximo e ângulo de ruptura. Os resultados mostraram que, apesar de todos os parafusos canulados seguirem os padrões recomendados, foram encontradas dispersões significativas entre os resultados verificados para os parafusos corticais de titânio, o que indica problemas de material ou manufatura. Os resultados mostraram valores mais elevados para torque de remoção que de inserção, o que, apesar de esperado, não é um efeito desejável, uma vez que facilita a fratura após a convalescência do paciente, em uma eventual remoção do parafuso. A análise dos resultados mostra a eficiência da metodologia desenvolvida, e chama a atenção para a confiabilidade dos componentes de órteses e próteses. / Human orthotic device components must be comfortable, able to execute the expected functions and, most of everything reliable. The focus of this work is the development and application of a surgical screw resistance analysis methodology. For this, a mechanical apparatus, consisting of a torque actuator and a data acquisition system was developed. The actuator, composed by an electric engine and reducer, applied torque on the tested screw, who transfers it to a load cell, especially developed, and thus to the data acquisition system. Cortical titanium and cannulated stainless steel bone screws were tested, from different manufacturers, for insertion and removal torque, maximum torque and rupture angle. The results showed that, despite that all cannulated screws had followed the recommended standards, it was found significant dispersion among the results for titanium cortical screws, which indicates manufacturing or material defects. Results also showed that removal torque was always higher than insertion torque. This is an undesirable, yet expected, effect, once fractures may come to happen after the healing of the patient, or even on the occasion of a substitution. The analysis showed the efficiency of the methodology developed, and opens a point of discussion on orthotic reliability.

Made available in DSpace on 2016-08-03T16:31:13Z (GMT). No. of bitstreams: 1 corpo da tese.pdf: 1970824 bytes, checksum: 355b870a1858f54c04a0669e13200fa3 (MD5) Previous issue date: 2009-03-24 / The pendulum appliance is efficient in correcting Class II malocclusions with upper dentoalveolar impairment. However, the loss in anchorage characterized by the mesial movement of maxillary pre-molars and by facial flaring and protrusion of maxillary incisors, represents a serious side effect of this appliance. The objective of this study was to evaluate the possible dental and skeletal alterations, both sagittal and vertical, resulting from the use of a modified Pendulum appliance anchored on mini-implants. Ten individuals were treated in this study; lateral radiographs were taken at the beginning of the study and immediately after removal of the Pendulum. In each individual, two mini-implants were installed on the palate, and received immediate charge by means of the activation of the modified Pendulum, supported on the temporary anchorage devices. None of the evaluated teeth displayed statistically significant vertical alterations; the same was true for vertical and sagittal skeletal alterations, as well as for overbite and overjet. As for statistically significant alterations, the first maxillary molar moved distally by approximately 5.6mm in 6.2 months, with average distal inclination of 7.10°. The second maxillary pre-molars moved distally by an average of 2.77mm, with inclination of 5.55°; the second maxillary molars presented an average distal movement of 4.6mm with inclination of 13.70°, values which were also considered statistically significant. The maxillary molar distalization system, consisting of the modified Pendulum appliance anchored on mini-implants, proved to be efficient in correcting Class II malocclusion, without causing the loss of anchorage effects.(AU) / O aparelho Pêndulo é eficaz na correção das más oclusões de Classe II, com comprometimento dentoalveolar superior. No entanto, a perda de ancoragem caracterizada pela mesialização dos pré-molares superiores, e pela vestibularização e protrusão dos incisivos superiores, constitui um grave efeito colateral deste dispositivo. O objetivo deste estudo foi avaliar as possíveis alterações dentárias e esquelética, sagitais e verticais, decorrentes do uso do Pêndulo modificado, ancorado em mini-implantes. Dez indivíduos foram tratados neste estudo, sendo que telerradiografias em norma lateral foram realizadas no início do tratamento, e imediatamente após a remoção do Pêndulo. Em cada indivíduo foram instalados dois mini-implantes no palato, que receberam carga imediata por meio da ativação do Pêndulo modificado, apoiado nestes dispositivos de ancoragem temporária. Nenhum dos dentes avaliados apresentou alterações verticais estatisticamente significantes; o mesmo ocorreu para as alterações esqueléticas verticais e sagitais, e para o trespasse vertical e horizontal. Com relação às alterações estatisticamente significantes, o primeiro molar superior moveu-se para distal aproximadamente 5,6mm em 6,2 meses, e com inclinação distal média de 7,100. Os segundos pré-molares superiores distalizaram em média 2,7mm e inclinaram 5,550; já os segundos molares superiores moveram-se em média 4,6mm para distal com uma inclinação de 13,700; valores estes também considerados estatisticamente significantes. O sistema de distalização de molares superiores, composto pelo Pêndulo modificado ancorado em mini-implantes, mostrou-se eficaz na correção da má oclusão de Classe II, sem produzir os efeitos de perda de ancoragem. (AU)

Made available in DSpace on 2016-08-03T16:31:13Z (GMT). No. of bitstreams: 1 Paula Rotoli Gregolin.pdf: 3137762 bytes, checksum: 32c795c8d755d12b05e4c3b75fcdba0c (MD5) Previous issue date: 2009-03-24 / The distalization of upper molars is a treatment option for Class II malocclusion when there is mainly a dentoalveolar involvement. Intraoral devices such as the Pendulum appliance doesn t need patient s compliance. However, they can cause undesirable effects, such as vestibularization of anterior teeth which participate in the anchorage and tipping of the distalized molars. After the appearance of Temporary Anchorage Devices (TADs), such as mini-implants, anchorage could be reached in a predictable and efficient way. Therefore, using a prospective study, dental alterations were evaluated after distalization of upper molars. A modified pendulum appliance supported by two mini-implants was inserted in the palate of 10 subjects (2 female and 8 male, mean age of 14.3 years old). The sample was composed of 20 dental casts digitalized in 3D and obtained in two stages: treatment beginning (T1) and after distalization with 1mm of overcorrection (T2). This enabled to quantify sagital and transversal dental alte rations, besides possible rotation and angulation movements and vertical movements. The results showed that in sagital direction there was an effective distalization, with statistical significance for upper second molars; upper first molars showed a mean measure of 4.34mm and 3.91mm, for right and left side, respectively; right and left second bicuspids showed a mean measure of 2.06mm and 1.95mm, respectively. On the other hand, anterior teeth showed anchorage loss. In transversal direction, the largest increase occurred in posterior teeth area. The rotation, angulation, and vertical movements of upper first molars suggested that there was a mesiobuccal rotation and a distal tipping of these teeth s crowns, for both sides; vertical measures showed that there was a significant movement only for the right first molar, with distal inclination due to distal cusp intrusion. This device showed to be efficient for Class II correction in a mean time of 6.2 months.(AU) / A distalização dos molares superiores é uma opção de tratamento da má oclusão de Classe II, quando o envolvimento é principalmente dentoalveolar. Dispositivos intrabucais como o aparelho Pêndulo, dispensam a colaboração do paciente quanto ao uso, porém promovem efeitos muitas vezes indesejáveis como a vestibularização dos dentes anteriores que participam na ancoragem e a inclinação dos molares distalizados. Após o surgimento dos Dispositivos de Ancoragem Temporária (DATs), como o mini-implante pode-se alcançar a ancoragem de forma previsível e eficiente. Com isto, por meio de um estudo prospectivo, foram avaliadas as alterações dentárias, promovidas pela distalização de molares superiores com um aparelho Pêndulo modificado, apoiado em dois mini-implantes instalados no palato de 10 indivíduos, sendo 2 do sexo feminino e 8 do masculino, com média de idade de 14,3 anos. A amostra foi composta por 20 modelos digitalizados em 3D, obtidos de em duas fases: no início do tratamento (T1) e após distalização com sobrecorreção de 1 mm (T2), permitindo quantificar as alterações dentárias sagitais, transversais e possíveis movimentos de rotação, angulação e movimentos verticais. Os resultados obtidos mostraram que no sentido sagital, houve uma efetiva distalização com significância estatística, para os segundos molares superiores; primeiros molares superiores em média de 4,34 mm e 3,91mm para o lado direito e esquerdo, respectivamente, e para os segundos pré-molares do lado direito e esquerdo de 2,06 mm e 1,95 mm, respectivamente. Porém, para os dentes anteriores, foi constatada a perda de ancoragem. No sentido transversal, o maior aumento ocorreu na região dos dentes posteriores. Os movimentos de rotação, angulação e vertical dos primeiros molares superiores, indicam que houve rotação mesiovestibular e inclinação distal das coroas destes dentes de ambos os lados; as medidas verticais, demonstram que houve movimento significativo apenas para o primeiro molar direito, com inclinação distal pela intrusão da cúspide distal. Este dispositivo mostrou-se eficaz na correção da Classe II em um tempo médio de 6,2 meses.(AU)

Made available in DSpace on 2015-07-22T20:49:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-01-28 / Objetivo: Avaliar o espaco interalveolar e a espessura da cortical ossea vestibular no uso das miniplacas de Champy (Sistema 2.0R) na regiao adjacente ao forame mentual. Metodos: Apos aprovacao pelo Comite de Etica em Pesquisa (CEP 1518/05) da UNIFESP e da UNEB (CEP 211/06) foram utilizadas cinquenta mandibulas secas, de individuos adultos dentados (25 do genero feminino e 25 do genero masculino) com idades entre 33 e 87 anos, pertencentes a colecao de ossos do Laboratorio de Anatomia Humana da Universidade do Estado da Bahia, Brasil. Foram excluidas mandibulas que apresentaram mas-formacoes ou alteracao patologica visivel, macroscopicamente, no corpo da mandibula. Inicialmente foi identificado um ponto (P) localizado 1,25 mm superiormente ao ponto medio da margem superior do forame mentual da mandibula (lado direito: P f e lado esquerdo: P f f). Esta distancia corresponde a metade da largura da ponte da miniplaca de titanio, Sistema 2.0R, que e utilizada superiormente ao forame mentual, a fim de eliminar zonas de tensao, quando do tratamento da fratura mandibular. Apos identificacao do ponto (P), a mandibula foi colocada sobre uma base de acrilico com uma haste vertical, planejada e confeccionada para identificacao dos pontos A L, B L, C L e A h, B h e C h que corresponderam as unidades 4.3; 4.4; 4.5 e 3.3; 3.4; 3.5. Apos a marcacao e perfuracao dos pontos, estes foram preenchidos com guta-percha previamente aquecida, que serviu como marcador para a tomografia computadorizada. A distancia interalveolar e a espessura da cortical ossea foram mensuradas por meio de cortes horizontais de tomografia computadorizada (TC). Resultados: Os dados encontrados foram submetidos a analise estatistica pelo teste t de Student e pelo teste de correlacao de Pearson com p .0,05. Nao foi encontrada espessura suficiente na cortical ossea vestibular para a fixacao adequada dos parafusos, embora houvesse uma distancia interalveolar suficientemente segura para introducao dos mesmos. Conclusoes: Os nossos dados apresentaram uma espessura ossea inferior a requerida pela tecnica de Champy, devido a anatomia da mandibula, na regiao mentual, nao evidenciar espessura ossea suficiente para suportar a colocacao das placas e parafusos da forma que preconiza a tecnica. / Objective: To assess the thickness of the mandibular bone in the interalveolar space corresponding to the dental units 3.3; 3.4; 3.5; 4.3; 4.4, 4.5, in the mental foramen region and the thickness of the bone cortical in the same region and to analyze the viability of fixating Champy miniplates (System 2.0®) with monocortical screws in the direction of the interalveolar space of the units 3.3, 3.4, 3.5, 4.3, 4.4, 4.5. Methods: Fifty dry mandibles of dentate adults (25 females and 25 males) aging from 33 to 87 years were used. These catalogued mandibles were acquired from the Human Anatomy Laboratory from the University of State of Bahia, state of Bahia, Brazil. Mandibles with malformations or macroscopic pathological changes in the body of the mandible were excluded. Initially we identified a point (P) located 1.25mm above the upper margin of the mental foramen of the mandible (right side: P´ and left side: P”). This distance corresponds to half of the width of the bridge of the titanium miniplate, System 2.0® that is generally used above the mental foramen in the Champy technique, whose objective is to eliminate tension zones when treating mandibular fractures. After identifying the (P) point, the mandible was placed over an acrylic base horizontally with a vertical rod, planned and constructed to identify the points A´, B´, C´ and A”, B” and C” which correspond to the units 4.3; 4.4; 4.5 and 3.3; 3.4; 3.5. After marking the points, the interalveolar distances were measured by indirect analysis using axial computed tomography (CT) cuts. After delimiting and perforating the points, these were filled with previously heated gutta-percha that served as a marker in the CT cuts. Five (05) mandibles of the sample were cut in a way as to allow direct biometry with the objective of comparing and validating the CT measurements. Results: The data show that the thickness of the vestibular cortical bone is not enough to adequately implant and fixate the screws even though the interalveolar distance is sufficiently safe to introduce them. The data point towards a deficiency in the bone support required to generate the procedures of the Champy technique since the anatomy of the mandible does not present elements that support placing the plates and screws in the way recommended by the technique. There is no adequate bone support to promote the necessary stability. / TEDE / BV UNIFESP: Teses e dissertações