Student Number : 8701355N - MDent research report - School of Oral Health Sciences - Faculty of Health Sciences / Purpose: The aim of this research project was to determine the fracture resistance to linear vertical compressive forces of acrylic and metal-reinforced acrylic fixed implant supported prosthesis cantilever arms. Methods: Ten non-reinforced and 10 reinforced acrylic superstructures were secured on five evenly distributed implants and subjected to linear axial compressive forces utilising an Instron® materials testing machine. The reinforcement consisted of commercially available preformed titanium metal strengthener bars. Force was applied to the cantilever arms 15mm distal to the distal most implant and two tests were conducted on each sample. The first drop in load recorded was noted as a fracture of the sample. Results: Fracture of the acrylic was noted at the distal most implant in both non-reinforced and the reinforced samples. The mean fracture value for the non-reinforced samples was 679N and for the reinforced samples, 628N. Conclusion: No significant difference between the fracture resistance of the two designs was noted.

Por meio deste estudo objetivou-se avaliar a viabilidade de um novo acesso artroscópico para o recesso palmar da articulação interfalângica distal em eqüinos pela bainha sinovial comum aos tendões flexores digitais, com as finalidades de proporcionar segurança e eficiência durante a artrocentese, permitir visualização efetiva das estruturas anatômicas, além de criar condições para manipulação de instrumentos artroscópicos. Foram utilizadas 20 peças anatômicas, correspondentes aos membros torácicos de 10 eqüinos. Os conjuntos de um a cinco formaram o Grupo I, cujo o acesso cirúrgico foi medial, e os conjuntos seis a 10 formaram o Grupo II, onde o acesso cirúrgico foi lateral. Posteriormente, avaliou-se o procedimento em animais de experimentação com a aplicação da técnica artroscópica proposta em seis articulações interfalângicas distais dos membros torácicos de três eqüinos (GIII), sem enfermidade previamente diagnosticada através de exames físicos e radiográficos. Os procedimentos no Grupo III foram efetuados sob anestesia geral, em decúbito lateral, e todos animais foram observados durante seis semanas. Neste período, além da avaliação dos parâmetros físicos, foram efetuados controles radiográficos contrastados, visando a avaliar a recuperação e o tempo necessário para oclusão da membrana divisória entre a bainha digital e o interior da articulação interfalângica distal. A técnica proposta alcançou os objetivos propostos, oferecendo nova alternativa para o acesso ao recesso palmar da articulação interfalângica distal nos eqüinos / This study was carried out in order to evaluate the viability of a new arthroscopic approach of the palmar recess of the the interphalangeal joint in horses through the synovial sheath that involves the digital flexor tendon. The purposes of the study were to provide safety and efficiency during arthrocentesis, to allow effective visualization of the anatomical structures and provide means for the manipulation of arthroscopic instruments. Initially, 20 anatomic parts corresponding to the forelimbs of 10 horses were used. Sets numbers 1 through 5 formed Group I in wich a medial surgical approach was performed. Sets numbers 6 through 10 formed Group II, in which there was a lateral surgical approach. Later, the procedure in experimental animals was analyzed. This analysis was done using the proposed arthroscopic technique in 6 distal interphalangeal joints of the forelimbs of three horses (GIII). There was no previously disease diagnosed through physical and radiographic exams. The procedures in Group III were done under put general anesthesia in the lateral recumbence position and all the animals were under observation during six weeks. In the post-operative period a physical and contrasted radiographic exams were done to evaluate the recovery as well as the necessary healing time of the membrane between the digital sheath and distal interphalangeal joint. The technique responded positively to its objectives offering a new alternative to the approach of the palmar recess in the distal interphalangical joint in horses

A Formação Tacuarembó (Jurássico Superior – Cretáceo Inferior), subdividida em Membro Batoví e Membro Rivera, aflora na região norte do Uruguai, nos departamentos de Rivera e Tacuarembó. O objetivo principal deste trabalho é a análise sedimentológica e estratigráfi-ca da Formação Tacuarembó, através da caracterização faciológica, a reconstrução dos modelos deposicionais e a definição das relações de contato entre os membros Batoví e Rivera. Para alcançar tal objetivo, foi realizado o levantamento, na escala 1:50, de um tes-temunho e de quarenta e uma seções colunares, estas divididas em sete transectas com base em sua distribuição espacial. Como resultado, foram detalhadas litofácies posterior-mente agrupadas em diferentes associações de fácies. O Membro Batoví é constituído por associações de fácies de (1) dunas eólicas, (2) lençóis de areia eólicos, (3) canais fluviais efêmeros, (4) canais fluviais perenes entrelaçados e (5) deltas. O Membro Rivera, por sua vez, é constituído essencialmente por associações de fácies de dunas eólicas. A intercala-ção entre depósitos fluviais, eólicos e deltaicos, com predominância de associações fluviais sugere que o Membro Batoví representa o modelo deposicional de porção distal de um sis-tema fluvial distributário Já o Membro Rivera caracteriza-se pelo sucessivo cavalgamento de dunas eólicas, sem a ocorrência de depósitos de interdunas úmidas ou encharcadas, definindo um sistema eólico seco. A mudança abrupta de sistemas deposicionais, marcada por uma superfície plana, por vezes com concentração de clastos, indica a existência de uma discordância entre os membros Batoví e Rivera. Aliado a isto, a mudança no modelo deposicional sugere uma alteração climática, passando de um clima arido a semi-árido du-rante a deposição do Membro Batoví, para um clima hiperárido ao longo da deposição do Membro Rivera. / The Tacuarembó Formation (Upper Jurassic - Lower Cretaceous), subdivided into Batoví Member and Rivera Member, crops in the northern region of Uruguay, in the Rivera and Tacuarembó departments. The main objective of the present work is the sedimentological and estratigraphic analysis of the Tacuarembó Formation, through the faciological charac-terization, reconstruction of the depositional models and definition of contact relations be-tween the Batoví and Rivera members. To reach such objective, a well-log and forty-one columnar sections were surveyed in a scale 1:50, and later the columnar sections were di-vided into seven transects, based on their spatial position. As a result, lithofacies were de-tailed and later grouped in different facies associations.The Batoví Member consists of associations of facies of (1) eolian dunes, (2) eolian sand sheets, (3) ephemeral fluvial channels, (4) perennial braided fluvial channels and (5) deltaic. On the other hand, the Ri-vera Member, is essentially constituted by facies associations eolian dunes. The intercala-tion between fluvial, eolian and deltaic deposits, with predominance of fluvial associations, suggests that the Batoví Member represents the depositional model of the distal portion of a distributary fluvial system. Contrastingly, the Rivera Member is characterized by the suc-cessive eolian dunes climbing, without the occurrence of wet or damp interdunes deposits, defining a dry eolian system. The abrupt change of depositional systems, marked by a flat surface, sometimes with clasts concentration, indicates the existence of an unconformity between the members Batoví and Rivera. Allied to this, the change in the depositional model suggests a climatic change, going from arid to semi-arid climate during the deposi-tion of the Batoví Member, to a hyperarid climate during the deposition of the Rivera Mem-ber.

Magister Scientiae Dentium - MSc(Dent) (Restorative Dentistry) / Loss of teeth has a negative impact on appearance, nutrition, function and diet. Rehabilitation of tooth loss is an important function of oral health care. Rehabilitation with removable prosthesis of mandibular terminal edentulous areas has been associated with more negative outcomes than of tooth-bounded regions.

Foram estudados prospectivamente os linfonodos, em 19 pacientes com adenocarcinoma de reto distal através de tomografia pélvica e linfocintilografia pélvica e realizado o estudo comparativo dos métodos, tendo como base à anatomia patológica e o estadiamento clinico-cirúrgico. Foram comparados os exames obtendo-se que os métodos não são concordantes. E a linfocintilografia é método mais sensível para linfonodos do que a tomografia / They were studied prospectivamente the lymph nodes, in 19 patient with adenocarcinoma of distal rectum through pelvic tomography and pelvic lymphoscintigraphy and accomplished the comparative study of the methods, having as based to the pathological anatomy and the staging practise-surgical. It compared the exams to each other obtaining itself that the methods are not concordant. And the lymphoscintigraphy is more sensitive method for lymph nodes than for

Introduction. Wrist (Colles') and forearm fractures commonly occur when a person falls on the outstretched forearm and the force exceeds bone strength. There is lack of experimental evidence testing the available force prediction models and assessing factors that determine forearm forces during a fall.<p> Objective. The primary objective was to compare experimentally measured force peaks (F1max-E and F2max-E) to the force peaks that were predicted by an engineering based force prediction model (F1max-M and F2max-M), at heights greater than 5cm. The second objective was to describe the relationships between the experimentally measured peak forces and forearm bone and muscle strength properties, body mass, and stature as a function of fall height.<p> Methods. Using 3D motion tracking, we assessed the first (F1max) and second (F2max) peak forces from 10 young adults (5 male; 5 female) who volunteered to fall from heights up to 25cm onto a foam covered force plate. Peripheral QCT was used to determine the bone strength index (BSIc), strength-strain index (SSIp), and muscle cross sectional area (MCSA) of each participant. Two 2x8 between-within factorial ANOVAs determined the difference between the experimental and model force peaks, with post hoc analyses at all fall heights. Pearson's correlation was used to determine the relationship between the pQCT-derived bone and muscle strength indices and the force peaks.<p> Results. There was no significant differences between F1max-E and F1max-M across all fall heights, but the model significantly over-predicted the F2max-E across all fall heights. After controlling F1max-E and F2max-E for body mass, the force peaks appeared to be weakly related to the anthropometric as well as bone and muscle strength outcomes (r=0.2-0.7, p>0.05). The relationship between bone and muscle strength outcomes appeared to have a tendency to get stronger at higher fall heights.<p> Conclusion. The model predicted experimental F1max, but not experimental F2max. This study presents preliminary pilot results. Larger sample size is needed to confirm whether incorporating bone and muscle strength estimates into fall force prediction models could enhance forearm fracture risk assessments.

Purpose: This study was conducted to evaluate the success of fixed space maintainers (fspms) placed by a sole dental practitioner in a private practice setting. The survey was conducted to evaluate the use of fspms by pediatric dentists and orthodontists. Methods: 899 fspms placed in 531 patients were evaluated. An online survey was sent to 1000 pediatric dentists and 1000 orthodontists. Results: The clinical success rate was 86.6%. The response rate for pediatric dentists surveyed was 43.0% but for orthodontists was only 7.0%. The vast majority of responding pediatric dentists (99.8%) and orthodontists (97.0%) placed fspms. The most common reason cited for failure by the pediatric dentists was cement loss (47.3%) and breakage by the orthodontists (30.4%). Conclusions: Fixed space maintainers had a high clinical success rate (86.6%) and were placed by the vast majority of responding pediatric dentists (99.8%) and orthodontists (97.0%).

Purpose: This study was conducted to evaluate the success of fixed space maintainers (fspms) placed by a sole dental practitioner in a private practice setting. The survey was conducted to evaluate the use of fspms by pediatric dentists and orthodontists. Methods: 899 fspms placed in 531 patients were evaluated. An online survey was sent to 1000 pediatric dentists and 1000 orthodontists. Results: The clinical success rate was 86.6%. The response rate for pediatric dentists surveyed was 43.0% but for orthodontists was only 7.0%. The vast majority of responding pediatric dentists (99.8%) and orthodontists (97.0%) placed fspms. The most common reason cited for failure by the pediatric dentists was cement loss (47.3%) and breakage by the orthodontists (30.4%). Conclusions: Fixed space maintainers had a high clinical success rate (86.6%) and were placed by the vast majority of responding pediatric dentists (99.8%) and orthodontists (97.0%).

Introduction. Wrist (Colles') and forearm fractures commonly occur when a person falls on the outstretched forearm and the force exceeds bone strength. There is lack of experimental evidence testing the available force prediction models and assessing factors that determine forearm forces during a fall.<p> Objective. The primary objective was to compare experimentally measured force peaks (F1max-E and F2max-E) to the force peaks that were predicted by an engineering based force prediction model (F1max-M and F2max-M), at heights greater than 5cm. The second objective was to describe the relationships between the experimentally measured peak forces and forearm bone and muscle strength properties, body mass, and stature as a function of fall height.<p> Methods. Using 3D motion tracking, we assessed the first (F1max) and second (F2max) peak forces from 10 young adults (5 male; 5 female) who volunteered to fall from heights up to 25cm onto a foam covered force plate. Peripheral QCT was used to determine the bone strength index (BSIc), strength-strain index (SSIp), and muscle cross sectional area (MCSA) of each participant. Two 2x8 between-within factorial ANOVAs determined the difference between the experimental and model force peaks, with post hoc analyses at all fall heights. Pearson's correlation was used to determine the relationship between the pQCT-derived bone and muscle strength indices and the force peaks.<p> Results. There was no significant differences between F1max-E and F1max-M across all fall heights, but the model significantly over-predicted the F2max-E across all fall heights. After controlling F1max-E and F2max-E for body mass, the force peaks appeared to be weakly related to the anthropometric as well as bone and muscle strength outcomes (r=0.2-0.7, p>0.05). The relationship between bone and muscle strength outcomes appeared to have a tendency to get stronger at higher fall heights.<p> Conclusion. The model predicted experimental F1max, but not experimental F2max. This study presents preliminary pilot results. Larger sample size is needed to confirm whether incorporating bone and muscle strength estimates into fall force prediction models could enhance forearm fracture risk assessments.

The formation of a continuous tubular network in the mammalian urinary system requires the interconnection of two epithelial populations with distinct cellular origins. The proximal component of the renal network is the nephron--a complex tubule responsible for much of the physiological action of the kidney. Nephrons connect to a collecting duct network to transport urine from the kidney to the bladder, via the ureter. I have used high-resolution image analysis of genetically labeled nephron and collecting duct networks together with apical and luminal markers to characterize the epithelial interconnection process in the developing kidney. Morphological protrusions at the distal end of the nephron precursor, adjacent to the tip of the collecting duct epithelium, precede luminal interconnection at the S-shaped body stage. Distal cells in the nephron precursor do not display clear epithelial junction complexes and show upregulation of phospho-myosin light chain, suggestive of a quasi-mesenchymal cell behavior. The close apposition of this group of cells with the collecting duct epithelium is facilitated by the absence on an intervening basal lamina. Live imaging of explanted kidneys suggests that distal cells break through into the lumen of the collecting duct epithelium and undergo cell death. No interconnection is observed upon Notch-mediated proximalization of distal cell fates. Furthermore, distal factor bone morphogenetic protein 2 (Bmp2) expression is lost in proximalized nephron precursor derivatives. Finally, I demonstrate that mice with specific loss of Bmp2 in nephron precursors and their derivatives results in a fraction of disconnected mature nephrons that later results in nephron atrophy and compromised renal function at juvenile stage compared to control mice. These data support a model in which the establishment of distal identity in nephron precursor cells closest to the nascent collecting duct epithelium leads to an active cell invasion that establishes a patent tubular interconnection between the nephron and collecting duct.