998 resultados para MIRANDA-RIBEIRO
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A Osteotomia Segmentar de Maxila ou Osteotomia Le Fort I Segmentada é um procedimento que tem se tornado, cada vez mais comum, nas cirugias para as correções das deformidades dentofaciais, conhecidas como Cirurgias Ortognáticas. Este procedimento é muito bem indicado para a correção das discrepâncias maxilares, nos diferentes planos e num único tempo cirúrgico, otimizando assim, o tempo de tratamento a que o paciente é submetido. A estabilidade esquelética transversal e a oclusal dos pacientes, que são submetidos a este tipo de osteotomia, tem sido objeto de estudo na literatura , assim como também, os potenciais riscos e complicações inerentes a este procedimento como, a desvitalização dentária, fístula oro-nasal, perda dentária, necrose de algum segmento da maxila ou até mesmo, de toda a maxila. O objetivo deste trabalho é apresentar o caso clínico de um paciente submetido à osteotomia segmentar de maxila, e fazer uma revisão da literatura abrangendo os últimos 10 anos, com artigos que abordam a estabilidade deste tipo de procedimento, assim como também os potenciais riscos e complicações aos pacientes submetidos a este procedimento. Utilizando algumas palavras chave na base de dados eletrônica PUBMED, 12 artigos foram selecionados para este trabalho, no período de 2002 a 2012. A Osteotomia Segmentar de Maxila é um procedimento estável e seguro, com baixo índice de complicação, quando indicado corretamente e com os devidos cuidados no pré, trans e pós operatórios.
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A reabsorção condilar interna no adolescente (RCIA) é uma doença progressiva que afeta a articulação temporomandibular (ATM) e que pode resultar em maloclusão, deformidade facial, disfunção de ATM e dor. O aparecimento desta doença ocorre entre os 10 e os 15 anos, sendo mais freqüente em adolescentes do sexo feminino. Esses pacientes apresentam sinais clínicos característicos como: ângulo do plano oclusal e do plano mandibular aumentados, retrusão progressiva da mandíbula e maloclusão Classe II, com ou sem mordida aberta. Nos exames de imagem (tomografia computadorizada e ressonância magnética), observa-se reabsorção interna dos côndilos e deslocamento dos discos articulares da ATM. Tendo em vista a dificuldade em determinar a causa da RCIA e a importância em eliminar a dor e melhorar a função mastigatória, este estudo se propôs a avaliar as alterações promovidas no posicionamento mandibular, a sintomatologia dolorosa e a estabilidade do tratamento da RCIA, utilizando o protocolo de tratamento (Dr. Larry M. Wolford) em pacientes adolescentes submetidos a cirurgia de reposicionamento do disco articular e cirurgia ortognática, realizadas no mesmo ato cirúrgico. Neste estudo retrospectivo, foram avaliadas as telerradiografias laterais adquiridas na avaliação inicial (T1), pré-cirúrgica (T2), pós-cirúrgica imediata (T3) e de maior acompanhamento, com pelo menos um ano pós-cirurgia (T4) e questionários de dor e função mandibular de uma amostra de 24 pacientes com maloclusão de Classe II (20 do sexo feminino e 4 do sexo masculino) diagnosticados com RCIA, os quais foram submetidos ao protocolo de tratamento composto pela cirurgia de reposicionamento do disco articular da ATM concomitantemente à cirurgia ortognática. O protocolo de tratamento utilizado mostrou-se bastante positivo, uma vez que a estabilidade foi adquirida e uma melhora significativa nos níveis de dor e função mandibular foram atingidos. O tratamento dos pacientes diagnosticados com RCIA, através do protocolo de tratamento proposto, é um procedimento estável e atua diretamente em um ganho na redução da dor.
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Este trabalho avaliou a eficiência mastigatória na maloclusão do tipo Mordida Aberta Anterior por meio do Me-mastig, dispositivo que pode ser utilizado no sentido de se mensurar a eficiência da mastigação, prometendo ser uma alternativa prática, rápida e eficiente para o exame da mastigação. O grupo experimental compôs-se de 106 crianças na faixa etária dos 07 aos 11 anos, divididos em 2 grupos, da seguinte forma: (A) Grupo de Mordida Aberta Anterior, contendo 51 crianças e (B) Grupo Controle, com trespasse vertical normal contendo 55 crianças. Procurou-se avaliar a eficiência mastigatória das crianças dos dois grupos e comparar os resultados, que mostraram que a mastigação do grupo mordida aberta anterior foi menos eficiente quando comparada à do grupo controle; fato que se pode explicar pelas características faciais dos indivíduos portadores da maloclusão estudada e também características da própria maloclusão de mordida aberta anterior. Conclusões, a mordida aberta anterior é responsável por uma diminuição significativa da a Eficiência Mastigatória e o dispositivo Me-mastig se mostrou um método eficaz, de fácil utilização e não dispendioso que pode ser usado na clínica diária para se medir ou avaliar a Eficiência Mastigatória.
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O laser de baixa intensidade (LBI) tem demonstrado efeitos bioestimulatórios na movimentação ortodôntica, acelerando a resposta celular e, reduzindo o tempo de tratamento. Entretanto, o uso do LBI seria mais efetivo com maior potência, menor tempo (única irradiação), ou a junção da menor potência e tempo em aplicação fracionada? Este estudo visou quantificar a movimentação de molares de 64 ratos e suas alterações histológicas, submetidos a uma força ortodôntica, liberada por meio de uma mola fechada de níquel-titânio (Niti/25gf), calibrada em 20gf. Os animais foram divididos em quatro grupos (cada grupo com 16 ratos), de acordo com os seguintes protocolos de irradiação do laser GaAlAs(780nm): grupo controle , submetidos à movimentação ortodôntica mas sem aplicação do LBI ; grupo total 1 (P=60mW/DE=15J/cm²/Et=6J/t=100seg), com a movimentação ortodôntica associada à única aplicação do LBI laser (P=60mW/DE=15J/cm²/Et=6J/t=100seg) no dia zero. Grupo total 2 em que o LBI foi aplicado no dia 0, segundo o protocolo P=20mW/DE=15J/cm²/E=6J/t=300seg;,; e Grupo fracionado em que o LBI foi aplicado nos dias 0, 3 e 7, empregando-se o protocolo (P=20mW/DE=5J/cm²/E=2J/t=100seg). Os sacrifício dos ratos foi realizado em quatro momentos (dias 1,4,8 e 15), sendo que 4 ratos de cada grupo foi sacrificado em cada um dos dias. A quantidade de movimentação ortodôntica foi mensurada in loco por meio de paquímetro digital, antes da instalação das molas e, imediatamente após o sacrifício dos animais. Para o exame histológico, as maxilas foram removidas, preparadas e coradas pelo sistema H/E. Os resultados foram avaliados pela Análise de Variância, seguida do teste Tukey (p<0,05). O grupo fracionado apresentou maior movimentação dentária frente aos demais nos dias 4 e 8, sendo que os grupos total 1 e 2 demonstraram maior movimentação dentária que o controle somente no dia 8. Não houve diferença estatisticamente significante entre os grupos total 1 e 2 em todo o período avaliado. Este estudo concluiu que, o laser de baixa intensidade acelerou a movimentação dentária, salientando-se o efeito da aplicação fracionada em relação às aplicações únicas.
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Introdução: A análise de Bolton, análise que quantifica o tamanho dentário, é uma referência importante para profissionais que buscam finalizações ortodônticas adequadas. Objetivo: O objetivo deste trabalho é verificar se há discrepância entre os indivíduos com oclusão normal natural e maloclusões de Classe I e de Classe II divisão 1 de Angle pertencentes a amostra selecionada, em relação aos valores encontrados por Bolton, bem como verificar também se há dimorfismo sexual. Metodologia: 3 grupos contendo 35 pares e modelos em gesso cada, separados pelo tipo de oclusão, pertencentes ao acervo do programa de pós-graduação em Ortodontia da Universidade Metodista de São Paulo foram medidos com paquímetro digital em sua maior distância mésiodistal desde 1º molar direito a 1º molar esquerdo, dos arcos superiores e inferiores, com dentição permanente. Os valores foram tabulados e a proporção de Bolton foi aplicada. Resultados: Respectivamente para os grupos 1, 2 e 3, a proporção total encontrada foi de 90,36 (DP±1,70), 91,17 (DP±2,58) e 90,76 (DP±2,45), e a proporção anterior foi de 77,73 (DP±2,39), 78,01 (DP±2,66) e 77,30 (DP±2,65). Conclusão: não houve dimorfismo sexual nem diferença estatisticamente significante comparando os valores aos sugeridos por Bolton.
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O objtivo deste estudo pros
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A literatura tem evidenciado que o modo respiratório alterado influencia nos aspectos estruturais e funcionais do sistema estomatognático. Objetivo: Comparar as medidas cefalométricas dos espaços aéreos naso e orofaríngeo entre respiradores nasais e com modo respiratório alterado (orais ou oronasais). Método: Este estudo de caráter exploratório e retrospectivo utilizou os prontuários de pacientes atendidos na Clínica de Ortodontia, compreendendo o período de 2000 a 2009, sendo que dos 87 indivíduos (má oclusão Classe I de Angle) que compuseram a amostra, 55 eram respiradores nasais (RN) e 32 apresentavam modo respiratório alterado (RON - oronasal ou oral), 47 pertenciam ao sexo feminino e 40 ao masculino, com idades entre 8,75 e 22 anos (média de 14,78 anos). Foram analisadas as telerradiografias em norma lateral, não submetidos a tratamento ortodôntico ou fonoaudiológica prévios. As variáveis de análise foram: idade, sexo, raça, modo respiratório e análise dos espaços naso e orofaringeano pelo método adotado por Zanelato. Por meio de análise estatística (teste t de Student e quiquadrado), os resultados foram interpretados quanto à sua significância. Resultados: Houve diferença estatisticamente significante quanto à idade dos grupos (RN>RON); de prevalência de homens (maior no grupo RON), de leucodermas em ambos os grupos, de via aérea súpero-anterior (menor no grupo RON) e tonsila faríngea (maior no grupo RON); e de tamanho de tonsila faríngea em melanodermas. As demais variáveis de análise não evidenciaram diferenças estatisticamente significantes. Conclusão: As medidas cefalométricas do espaço nasofaringeano (menor no grupo RON) e da tonsila faríngea (maior no grupo RON) diferiram entre os grupos e o espaço orofaringeano não se mostrou diferente entre os grupos. Demais fatores, que não exclusivamente o espaço nasofaríngeo e a tonsila faríngea, podem predispor o indivíduo à respiração oronasal ou predominantemente oral e o ortodontista, em sua rotina clínica, pode avaliar objetivamente as particularidades de cada caso e, desta forma, proceder com condutas adequadas o mais precocemente possível.
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Among the species of freshwater shrimp being cultivated, Macrobrachium rosenbergii stands out. Knowledge about the behavior of this species and the influence of certain factors on its development can help optimize management practices and minimize the likely impacts shrimp farming has on the environment and the animals themselves. The objective of this study was to characterize the species' behavior during early stages of development under different stocking densities over a 24-hour cycle. Ten day old postlarvae were transferred from the Jundiaí School of Agriculture (EAJ - Escola Agrícola de Jundiaí) in Macaíba (RN), Brazil to the Shrimp Behavior Laboratory (LSPR - Laboratório de Estudos do Comportamento do Camarão) at the Federal University of Rio Grande do Norte (UFRN), where they were weighed and measured. Eight aquaria with constant temperature, aeration and filtration, and subjected to a12 h light/12 h dark cycle were used for each experiment. Each aquarium also contained two shelters made of bricks and the water quality was monitored weekly. Behavioral observations were made at two densities: 25 individuals/m-² and 40 individuals/m-². The methods for recording behaviors were: behavioral sampling – enter and leave the shelter, exploring on the substrate, exploring in the water column, move away, attack, pursuit and cannibalism; scan sampling - inactivity, feeding, exploration, digging, swimming, cleaning and staying in the shelter. Observations were made during a 15 minute period/per aquarium at a frequency of 4 times daily, for 4 days/week, and over 4 weeks. Food was provided 2 times/day for each aquarium population, immediately before the 1st and 3rd observation periods. Our results demonstrate that at high density, there is an increased frequency of agonistic behavior; during the light phase, there is a greater frequency of behaviors that result in less exposure (inactivity, cleaning and staying in the shelter); during the dark phase, there is an increased frequency of behaviors that result in greater exposure (feeding, exploration, swimming and digging); at times of feed offer, there is an increased frequency of leaving the shelter, moving away, pursuit, feeding, exploration and swimming. At low density, the animals showed a lower frequency of agonistic behaviors, greater weight gain and higher growth rates, which indicates that this is a more favorable growing environment for cultivation and when applied, can generate better living conditions, favor survival rates and increase management success
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Hebb proposed that synapses between neurons that fire synchronously are strengthened, forming cell assemblies and phase sequences. The former, on a shorter scale, are ensembles of synchronized cells that function transiently as a closed processing system; the latter, on a larger scale, correspond to the sequential activation of cell assemblies able to represent percepts and behaviors. Nowadays, the recording of large neuronal populations allows for the detection of multiple cell assemblies. Within Hebb’s theory, the next logical step is the analysis of phase sequences. Here we detected phase sequences as consecutive assembly activation patterns, and then analyzed their graph attributes in relation to behavior. We investigated action potentials recorded from the adult rat hippocampus and neocortex before, during and after novel object exploration (experimental periods). Within assembly graphs, each assembly corresponded to a node, and each edge corresponded to the temporal sequence of consecutive node activations. The sum of all assembly activations was proportional to firing rates, but the activity of individual assemblies was not. Assembly repertoire was stable across experimental periods, suggesting that novel experience does not create new assemblies in the adult rat. Assembly graph attributes, on the other hand, varied significantly across behavioral states and experimental periods, and were separable enough to correctly classify experimental periods (Naïve Bayes classifier; maximum AUROCs ranging from 0.55 to 0.99) and behavioral states (waking, slow wave sleep, and rapid eye movement sleep; maximum AUROCs ranging from 0.64 to 0.98). Our findings agree with Hebb’s view that neuronal assemblies correspond to primitive building blocks of representation, nearly unchanged in 10 the adult, while phase sequences are labile across behavioral states and change after novel experience. The results are compatible with a role for phase sequences in behavior and cognition
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Macrobrachium rosenbergii is a freshwater prawn which presents agonistic behavior and heterogeneous growth. It is known that captive conditions can intensify agonism causing injuries and decreased survival, generating a condition of poor welfare. Based on this, we aim to investigate the behavior of M. rosenbergii in the juvenile phase according to different types of shelter and frequencies of feed offer, emphasizing their agonistic behavior. For this, juveniles were observed in the laboratory in three steps. At step I we characterized the behavioral profile; prawns were kept in eight aquariums (27 prawns/m2 ), identified and observed four times along both phases of 24 h light cycle. At step II (2 experiments), we evaluated the use of shelters (brick or polyethylene rolls) and their influence on agonism by the animals. For classification of animals in dominance rank, the method used was David's Score. At step III (3 experiments), we evaluated different frequencies of feed offer on the behavior of individuals, in particular agonism. Results showed that juveniles do not present a pattern activity/inactivity between the phases of the light cycle. We identified a dominance hierarchy among individuals taking advantage of access to food by the dominant, which showed greater weight gain although the frequency of intake did not differ between individuals. The type of shelter influenced the behavior of animals. Brick shelter generated a higher frequency of permanence and a reduction in the frequency of agonistic interactions. The distribution of food more frequently throughout the day, decreased the motivation of animals for food, as well as to fight. Prawns fed four times showed lower frequency of feed intake and agonistic interactions. Thus, we conclude the shelters which reduce animal’s detection by coespecifics and offer the food four times along the day reduce agonistic behavior. This result causes na improvement in life quality of the prawns and also in its quality as final product.
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The solution of partial differential equation of seepage problems is difficult to find analytically, especially for situations that involve great complexity. To overcome this problem, software based on finite differences and finite elements are usually used. This work presents the use of a finite element software, the GEO5, to solve the seepage problem at a dam of very complex section, the dam Eng. Armando Ribeiro Gonçalves, which at the end of its construction suffered rupture of the upstream slope at the central dam and then went through a process of reconstruction and auscultation. The analyses were performed for the operating condition of the reservoir, with an established flow. A numerical model was developed based on the level readings of the reservoir water and their piezometric readings as a proposal for the evaluation and future behavior prediction of the dam on established flow conditions. The use of constitutive models with the aid of computer systems is reflected in a way to predict future risk situations so they can be prevented
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Spinal cord injury causes permanent disabling manifestations, affecting the anatomic integrity, bodily changes and functional limitations related to the disability state. It was aimed to analyze the social representation, stress level and experiences of fishermen victims of spinal cord injury caused by diving accident in the Northern beaches of Brazil. It is a descriptive - exploratory study with quantitative, qualitative and representational data developed i n fishermen’s villages in nine beaches of Northern shore/RN, between October 2013 to August 2014, after the approval of the Ethics Committee in Research of the Universidade Federal do Rio Grande do Norte, under the number 431.891/2013, CAAE 20818913.0.0000 .5537. The sample was composed by 44 fishermen with spinal cord injury, defined from inclusion and exclusion criteria of the participants. It was used as instrument to collect the data a semi structured interview. Quantitative data was analyzed by descrip tive statistics, showing the data through table, boxes and graphics by Microsoft Excel. Data from interviews were submitted to the software called Analyse Lexicale par Contexte d’un Ensemble de Segments de Texte (ALCESTE) using the analysis of the Social R epresentation Theory and Center Core Theory. It is shown the outcomes of the research through four articles, following the normative recommendations of the journals. Participants of the study were all male, age mean 49,6 years, elementary school (68,2%), m arried (77,3%); paraplegia sequel (50,0%). Most of them showed stress (75,0%), almost in the exhaustion stage (33,3%), prevalent insomnia symptoms (95,5%) in the last hours; hypertension (97,7%) in the last week and sexual troubles (95,5%) in the last mont h). Decompressive illness caused spinal cord injury (57,1%), occurred prevalently in low summer (75,0%), northern shore (96,4%), having as main consequences the paresthesia and pain in the upper and lower limbs (67,9%), followed by death (25,0%). Interview analysis under the understanding of Social Representation of spinal cord injury allowed the appearance of seven categories: Treatment: limitation and expectative; Spinal Cord injury: before and after; Retirement: reality yet to come; Disability: dependenc y, incapacity, vulnerability; Overcoming and autonomy; Self feelings: physics losses and new start; Life and labor: impediments, plans and changes. The center core of the representation is found in the first category by the expectative and limitation on th e treatment, meanwhile the outskirt elements are in seventh and third categories. Physics limitation for fishing activities and retirement expectative is the most outstanding of the structure. Social representation concerning spinal cord injury is found in a transaction moment between before and after with the prevented fishing activity, coping of the situation with the potential remaining. The anchoring is established in the desire for changes related to the improvements of life and health conditions exper ienced day by day through faith. This study finishes pointing out the range of the objectives, which topic is relevant for public health of fishermen. It is suggested prevention measures, promotion and health recovery of fishermen, besides safe, healthy an d worthy conditions as a compromise of social and health politics.
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This study arose from an interest in knowing the reality of mental health care in Rio Grande do Norte (RN) on the advances and challenges in the intersectoral agreements paths and consolidation of the Psychosocial Care Network (RAPS) from the state. Considering problematic and concerns were defined as objectives: Identify the knowledge of managers of Rio Grande do Norte on the National Mental Health Policy (PNSM) in the RN State; Describe the activities developed by health professionals in the individual service offered in the CAPS from RN; Understanding the relationship of managers’ knowledge on national mental health policy in professionals’ practice working in the the CAPS from the countryside. It is a descriptive study with a quantitative and qualitative approach, carried out in 30 CAPS from RN’s countryside, where 183 professionals answered a structured questionnaire with closed questions about the activities they do in individual care; and 19 mental health coordinators of municipalities and the state coordinator of RAPS were interviewed about their knowledge on the Mental Health Policy. Data were collected after approval by the Research Ethics Committee of the Federal University of Rio Grande do Norte, with the number 508.430 CAAE: 25851913.7.0000.5537 from August through October of 2014 in 26 municipalities with CAPS from the state. Quantitative data were tabulated and analyzed using a descriptive statistics aided by the software Statistical Package for the Social Scienses (SPSS) version 20.0. The qualitative data were prepared in a corpus and analyzed through software Analyse Lexicale par Contexte d’um Ensemble de Segments de Texte (ALCESTE) that allow to perform textual statistical analysis and categorization from their comments, submitted to Bardin content analysis. Five categories were generated approaching the managers’ knowledge, namely: Back to society: leadership and users’ role and autonomy; The gap between policy and practice; Barriers that affect the service; Structuring the Psychosocial Care Network; Multidisciplinary team: attribuitios and activities. The CAPS professionals’ ages ranged from 20 to 58 years, prevailing females, with 76.5% of the total, the majority were social workers (16.8%), psychologists (15.3%), nurses (14.8%) and nursing technicians (14.8%). The results showed precariousness in care associated with physical workload regard to high workload and low wages of the CAPS professionals' and, also, it was possible to observe a large involvement of professionals in care delivery, despite the difficulties encountered in services. It was found little knowledge in managers regarding the National Mental Health Policy having as causes of this reality the poor education and training of these professionals. The responses of professionals working in care reveals strong consistency with what is expected of a psychosocial care service. Points up as a thesis of this study that the psychiatric reform and mental health policy in Rio Grande do Norte is following a structural expansion process, but with precariousness of services from a still unprepared management to act in a psychosocial context.
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The reformist movements in the field of mental health have pointed battle flags, among which the prioritization of production of mental health care out of the asylum environment should be highlighted, aiming the reduction of psychiatric beds, greater control over the hospitalization, family co-participation and the rescue of the citizenship of the social players involved. With the progressive reduction of asylum beds, associated with a lot of structural problems in the health services, the occurrence of crises outside the hospital environment has been increasingly frequent, thus giving the family an important therapeutic role. In face of this scenario, there is an urgent need to understand the social construction of the care for psychiatric emergencies, identifying the meanings assigned by family members to their constituent aspects. This study seeks to answer the following research question: what are the social representations of family members about the care of psychiatric emergencies in the city of Mossoró, Rio Grande do Norte? Therefore, the aim is to analyze the social representations of family members about the care of psychiatric emergencies in the city of Mossoró, Rio Grande do Norte. This is an exploratory and descriptive study, with a mixed approach, making use of multimethods: for collection, the semi-structured interview and the Technique of Free Association of Words; for data analysis, the Thematic Analysis of Bardin and its steps was used, with the informational support of the softwares ALCESTE (Analyse Lexicale par Contexte d'un Ensemble de Segments de Texte) and Iramuteq (Interface de R pour les Analyses Multidimensionnelles de Textes et de Questionnaires); and the theoretical support of social representations. The study participants totaled 72, and they were selected from the following criteria: older than18 years, with degree of kinship with users suffering from some mental and behavioral disorder, and who have already witnessed a situation of crisis, rescued by the SAMU or other means and taken to the psychiatric hospital or general emergency room. Preliminary results point out: 1.Previous note of the research project with the aim to disseminate it in the scientific community and ensure the intellectual property of the work; 2.The contextual analysis of the care for emergencies in the study place. Reflection about the phenomenon provide a name to the care for the psychiatric emergencies, which is called immediate context; the technical and operational aspects that influence the care, as a specific/ general context; and mental health policies in Brazil are identified as metacontext; 3. The systematic review from randomized clinical trials in the databases PubMed, COCHRANE, LILACS, SciELO and SCIRUS, with the use of the descriptors: ‘Physical restraint’, ‘Psychiatric emergency services’, ‘Restraint’, ‘Physical and Emergency Services’, ‘Psychiatric’. Only one work met the search protocol criteria: a short-term essay that records limited results about the proportion of people who are in restraint and seclusion. It does not show statistically significant results in relation to indications, contraindications and risks of the use of physical restraint; 4. The social representations of the care for psychiatric emergencies. The study results point to the presence of five thematic categories: 1. feeling in the face of the crisis/care; 2. thoughts and perspectives about the crisis/care; 3. centrality of care in the medical- medication-hospitalization triad; 4. the thinking/acting in the face of the use of physical restraint and police force; 5. periodicity of crises. The central core of the representation is in the first category, whilst the peripheral elements are in the third and fifth categories. The contrast zone is in the second and fourth categories. The sadness is the most prominent element of the structure. The social representations about the care for psychiatric crises are at a time of transition between the hegemonic and reformist models, with the traditional aspects being predominant, but already showing peripheral and contrast elements that point to a possible change in the representational field.
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PURPOSE: To compare and to evaluate the stability of the retentive force of cobalt-chromium (Co-Cr) circumferential clasps (control) to those with an acetyl resin retentive arm. METHODS: Sixteen specimens with a couple of circumferential clasps were made using Co-Cr over a metal model providing 0.25 mm undercuts. Eight specimens were fabricated without the anterior retentive arm, which was made later using acetyl resin (Dental D). Insertion and removal simulation test was performed through 7250 cycles. The retentive force was recorded in Newtons (N) for periods corresponding to 0, 1, 2, 3, 4, and 5 years. The data were subjected to ANOVA and Tukey test to compare periods and to Student's t test to compare groups (α=0.05). RESULTS: Mean (SD) is presented for Co-Cr and resin groups, respectively: 8.09(3.05) and 2.79(1.57) in period 0; 10.48(4.25) and 3.32(1.92) in 1 year; 10.09(4.15) and 3.47(1.81) in 2 years; 9.87(4.30) and 3.46(1.87) in 3 years; 9.46(3.93) and 3.27(1.59) in 4 years; 9.63(3.79) and 3.41(1.59) in 5 years. There were significant differences for Co-Cr between periods of 0 and 1 (p<0.001), 0 and 2 (p<0.01) and 0 and 3 (p<0.05). In the resin group, no significant differences were found between periods (p>0.05). Comparisons between the groups showed statistical differences for all tested periods: 0 (p=0.0012), 1 (p=0.0013), 2 (p=0.0019), 3 (p=0.0031), 4 (p=0.0027) and 5 years (p=0.0014). CONCLUSIONS: Acetyl resin retentive arms, even if only in the anterior clasps, can significantly reduce the retentive force, but this force remained stable after 5 years of simulated use.