994 resultados para Má oclusão de Angle Classe I
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The Kaposi-associated Herpesvirus (KSHV) also known as Human Herpesvirus 8 (HHV-8) is associated with the development of Kaposi’s sarcoma (KS) and others limphoprolipheratives diseases such as Primary Effusion Lymphoma (PEL) and Multicentric Castleman Disease (MCD). Even though the virus is considered lymphotropic, it is able to infect others cell types such as macrophages, dendritic cells, endothelial cells, monocytes and fibroblasts. After infection, KSHV be latent expressing essential viral genes to its maintenance in a infected cell. However, in some circumstances may occur the reactivation of lytic cycle producing new viral particles. K1 protein of KSHV interferes in the cellular signaling inducing proliferation and supporting cellular transformation. K1 is encoded by viral ORF-K1, which shows high variability between different genotypes of KSHV. So far, it is not clear whether different isoforms of K1 have specific immunobiological features. The KSHV latency is maintained under strict control by the immune system supported by an adequate antigen presentation involving Human Leucocyte Antigen (HLA) class I and II. Polymorphisms of HLA class I and II genes confer an enormous variability in molecules that recognize a large amount of antigens, but also can increase the susceptibility to autoimmune diseases. Therefore, the present study aims to genotype HLA class I (A and B) and class II (DR and DQ) from volunteers to identify haplotypes that can provide better response to K1 epitopes of different KSHV genotypes. First of all, 20 volunteers were selected to genotype HLA genes. In our results we observed prevalence of certain HLA class I haplotypes as HLAA1, HLA-A2, HLA-A24, HLA-A26, HLA-B8, HLA-B18 e HLA-B44. After the in silico analysis using BIMAS and SYFPEITHI databases, we observed high scores for epitopes from the B genotype of KSHV, indicating...(Complete abstract click electronic access below)
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In malocclusion studies, may happen not only dental discrepancies but even skeletal discrepancies. In Class III malocclusion can be observed underdeveloped maxilla, mandible protraction or both of them, and, in most of the times associated with a narrow maxilla that causes anterior or posterior crossbites, in one side or in two sides. The aim of this case report is to evaluate the facial profile and occlusal effects of interceptive orthodontics therapy. The treatment with upper arch expansion and maxilla protraction was done in an early age to be effective in the circummaxillary sutural system and to make the orthopedic effect easier. The facial mask used is positioned on two facial points and allows an anterior maxillary replacement. Patients’ compliance is important to reach treatment success, this because using the mask still in this growth and development phase is essential to make the facial and occlusal effects happen. It is important to mention that patients with Angle Class III malocclusion need to be followed till the end of their growth.
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Two treatment options are available for adult patients with skeletal Class II malocclusion caused by mandibular deficiency: combined mandibular advancement surgery and orthodontic treatment or mandibular advancement appliance. This study aimed to analyze the effects of two therapeutic modalities of Class II malocclusion treatment with mandibular deficiency. Two distinct individuals with Class II malocclusion division 1 and mandibular deficiency were treated after growth spurt. The first individual used the Herbst appliance as a therapeutic option and the second individual was treated with bilateral sagittal osteotomy. The cephalometric, occlusion and face results were evaluated for both individuals. Correction of Class II malocclusion was observed on both Herbst and surgery patients resulting on a normal occlusal relationship with normal overjet and overbite. Therefore it was concluded that Herbst appliance can be used to treat borderline skeletal Class II in adult patients.
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Patients with Class II division 2 malocclusion and mandibular retrusion have limited treatment options after the growth peak, such as surgical-orthodontic treatment or mandibular advancement devices. Among bite-jumping devices, the Herbst appliance allows greater increase of mandibular growth since it does not require patient compliance and allows continuous use. This case report presents the treatment of a Class II division 2 malocclusion in a patient after growth peak, performed in two stages. The first stage included the upper incisors proclination and overjet increase with multibracket appliance to benefit next stage. The second stage involved mandibular advancement using Herbst appliance aiming to correct the Class II molar relationship. The treatment resulted in a stable occlusion with periodontal health, normal functions and facial aesthetics improvement. Dental and skeletal changes arising from treatment could be assessed by cephalometric analysis and superimposition of pretreatment and post-treatment cephalometric tracings. Antero-posterior discrepancy was corrected by means of dental movement as well as by mandibular growth increment stimulated by the Herbst appliance.
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Objective: evaluate the immediate dental and skeletal changes induced by the Herbst appliance on early treatment of Angle´s Class II malocclusion. Material and Method: several electronic databases such as Scopus, Pub Med, Medline, Cochrane Library, Lilacs and Scielo were searched. The abstracts that fullfilled the selection criteria were selected and those that did not provide enough information about these criteria were selected but the final decision of including them or not on the research, was taken after the complete reading of the article. The selection criteria were: clinical studies with Class II individuals, both male and female, with initial age of 7 to 10 years, treated with the Herbst appliance that analysed the dental and/or skeletal changes evaluated on lateral cephalometric radiographs; researches where the treatment performed did not involve extractions or surgical interventions; studies that included patients without syndromes or health concerns and articles published in English or Portuguese. Results and Conclusions: five articles were selected. The articles showed that significant changes happened in the mandibular sagittal lenght, on facial convexity angle, on maxillo-mandibular relationship, on retroclination of the upper incisors and on distal movement of the upper molars, on proclination of the lower incisors and on extrusion of the lower molars. The appliance exerted a limited effect on the anterior relocation of the maxillary complex and on facial heights. However, more studies about the performance of the Herbst appliance on early treatment of Class II are needed.
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Patients are looking for esthetic and functional changes when seeking orthodontic treatment and expect the remaining of a stable occlusion. Occlusion stability is one of the goals of the orthodontist; however, dental relationships changes in long-term can occur leading to a relapse of the treatment. Teeth and shape of arches tend to return to the original form, been the retention phase important after the appliance removal, even after several years of post-treatment. This article approaches a submission of a clinical case of Class II division 1 treated with extraction of premolars analyzing its long-term stability.
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Class III malocclusion is less common occlusal relationship, covering less than 5% of the population. There are various forms of treatment in Class III malocclusion. Depending on how the form is expressed Class III and age of the patient, the therapy may be orthopedic and orthodontic surgical orthodontics. The objective was to review the literature of the last 10 years about ways to compensatory treatment of Class III malocclusion. Several articles were published between 04/2003 and 04/2013 in the Pubmed database from the keyword "Class III malocclusion". However, only 19 articles that addressed the compensatory treatment of Class III were selected. Based on the selected items it was concluded that the treatment of Class III malocclusions in children before the peak of pubertal growth has better prognosis with greater effects orthopedic and orthodontic minor effects. The ideal treatment option for this condition is the Rapid maxillary expansion associated with maxillary protraction of the same. The treatment of Class III malocclusion in young people after the peak of pubertal growth is doubtful prognosis. You can opt to treat rapid maxillary expansion and maxillary protraction of the same or fixed appliance, however, orthopedic effects can be the same or smaller than the orthodontic effects, depending on the age of the patient. Depending on the degree of Class III malocclusion in adults, the treatment will consist of dental compensations or orthognathic surgery.
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Pós-graduação em Odontologia Restauradora - ICT
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Pós-graduação em Odontologia Restauradora - ICT
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OBJECTIVE: Define and compare numbers and types of occlusal contacts in maximum intercuspation. METHODS: The study consisted of clinical and photographic analysis of occlusal contacts in maximum intercuspation. Twenty-six Caucasian Brazilian subjects were selected before orthodontic treatment, 20 males and 6 females, with ages ranging between 12 and 18 years. The subjects were diagnosed and grouped as follows: 13 with Angle Class I malocclusion and 13 with Angle Class II Division 1 malocclusion. After analysis, the occlusal contacts were classified according to the established criteria as: tripodism, bipodism, monopodism (respectively, three, two or one contact point with the slope of the fossa); cuspid to a marginal ridge; cuspid to two marginal ridges; cuspid tip to opposite inclined plane; surface to surface; and edge to edge. RESULTS: The mean number of occlusal contacts per subject in Class I malocclusion was 43.38 and for Class II Division 1 malocclusion it was 44.38, this difference was not statistically significant (p>0.05). CONCLUSIONS: There is a variety of factors that influence the number of occlusal contacts between a Class I and a Class II, Division 1 malocclusion. There is no standardization of occlusal contact type according to the studied malocclusions. A proper selection of occlusal contact types such as cuspid to fossa or cuspid to marginal ridge and its location in the teeth should be individually defined according to the demands of each case. The existence of an adequate occlusal contact leads to a correct distribution of forces, promoting periodontal health.
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La tagatose-1,6-biphosphate aldolase de Streptococcus pyogenes est une aldolase qui fait preuve d'un remarquable manque de spécificité vis à vis de ses substrats. En effet, elle catalyse le clivage réversible du tagatose-1,6-bisphosphate (TBP), mais également du fructose-1,6-bisphosphate (FBP), du sorbose-1,6-bisphosphate et du psicose-1,6-bisphosphate, quatre stéréoisomères, en dihydroxyacétone phosphate (DHAP) et en glycéraldéhyde-3-phosphate (G3P). Aldolase de classe I, qui donc catalyse sa réaction en formant un intermédiaire covalent obligatoire, ou base de Schiff, avec son susbtrat, la TBP aldolase de S. pyogenes partage 14 % d’identité avec l’enzyme modèle de cette famille, la FBP aldolase de muscle de mammifère. Bien que le mécanime catalytique de la FBP aldolase des mammifères ait été examiné en détails et qu’il soit approprié d’en tirer des renseignements quant à celui de la TBP aldolase, le manque singulier de stéréospécificité de cette dernière tant dans le sens du clivage que celui de la condensation n’est toujours pas éclairci. Afin de mettre à jour les caractéristiques du mécanisme enzymatique, une étude structurale de la TBP aldolase de S. pyogenes, un pathogène humain extrêmement versatile, a été entreprise. Elle a permis la résolution des structures de l’enzyme native et mutée, en complexe avec des subtrats et des inhibiteurs compétitifs, à des résolutions comprises entre 1.8 Å et 2.5 Å. Le trempage des cristaux de TBP aldolase native et mutante dans une solution saturante de FBP ou TBP a en outre permis de piéger un authentique intermédiaire covalent lié à la Lys205, la lysine catalytique. La determination des profils pH de la TBP aldolase native et mutée, entreprise afin d'évaluer l’influence du pH sur la réaction de clivage du FBP et TBP et ìdentifier le(s) résidu(s) impliqué(s), en conjonction avec les données structurales apportées par la cristallographie, ont permis d’identifier sans équivoque Glu163 comme résidu responsable du clivage. En effet, le mode de liaison sensiblement différent des ligands utilisés selon la stéréochimie en leur C3 et C4 permet à Glu163, équivalent à Glu187 dans la FBP aldolase de classe I, d’abstraire le proton sur l’hydroxyle du C4 et ainsi d’amorcer le clivage du lien C3-C4. L’étude du mécanimse inverse, celui de la condensation, grâce par exemple à la structure de l’enzyme native en complexe avec ses substrats à trois carbones le DHAP et le G3P, a en outre permis d’identifier un isomérisme du substrat G3P comme possible cause de la synthèse des isomères en C4 par cette enzyme. Ce résultat, ainsi que la decouverte d’un possible isomérisme cis-trans autour du lien C2-C3 de la base de Schiff formée avec le DHAP, identifié précedemment, permet de cerner presque complètement les particularités du mécanisme de cette enzyme et d’expliquer comment elle est capable de synthétiser les quatres stéréoisomères 3(S/R), 4(S/R). De plus, la résolution de ces structures a permis de mettre en évidence trois régions très mobiles de la protéine, ce qui pourrait être relié au rôle postulé de son isozyme chez S. pyogenes dans la régulation de l’expression génétique et de la virulence de la bactérie. Enfin, la résolution de la structure du mutant Lys229→Met de la FBP aldolase de muscle en complexe avec la forme cyclique du FBP, de même que des études cristallographiques sur le mutant équivalent Lys205→Met de la TBP aldolase de S. pyogenes et des expériences de calorimétrie ont permis d’identifier deux résidus particuliers, Ala31 et Asp33 chez la FBP aldolase, comme possible cause de la discrimination de cette enzyme contre les substrats 3(R) et 4(S), et ce par encombrement stérique des substrats cycliques. La cristallographie par rayons X et la cinétique enzymatique ont ainsi permis d'avancer dans l'élucidation du mécanisme et des propriétés structurales de cette enzyme aux caractéristiques particulières.
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Este estudo avaliou os efeitos esqueléticos da tração reversa da maxila utilizando imagens 2D (telerradiografia lateral) geradas a partir da tomografia de feixe cônico (imagens 3D). A amostra foi composta por 20 crianças (15 do gênero feminino, e 5 do masculino), com idade variando de 5,6 a 10,7 anos que apresentavam má-oclusão de Classe III de Angle. A tomografia foi realizada antes do tratamento (T1) e logo após o tratamento (T2). O tratamento foi realizado por meio da tração reversa da maxila utilizando-se o aparelho expansor Hyrax associado à máscara facial individualizada, com força de 600 a 800g de cada lado, durante 14 horas por dia. A correção da relação de caninos em Classe I ou com sua sobrecorreção em Classe II foi obtida após 4 a 8 meses de tratamento. Para verificar o erro sistemático e casual foi utilizado o teste t pareado e a fórmula de Dahlberg, respectivamente. O teste t pareado (p<0,05) mostrou diferença significante entre as medidas cefalométricas obtidas em T1 e T2. Na maxila houve aumento do SNA 2,2°, A-Nperp 1,47mm e em Co-A 2,58mm. Na mandíbula, SNB diminuiu -0,54° e P-Nperp, -1,45mm, enquanto Co-Gn aumentou 1,04mm. Houve melhora na relação maxilo-mandibular ANB 2,74° e Wits 4,23mm. As variáveis GoGn.SN, Gn.SN, FH.Md, Mx.Md, e AFAI aumentaram demonstrando que houve uma rotação da mandíbula no sentido horário. O plano palatino rotacionou no sentido anti-horário. Pode se concluir que o tratamento de tração reversa da maxila na idade precoce promoveu uma melhora na relação maxilo-mandibular devido a um avanço da maxila e um deslocamento da mandíbula para baixo e para trás.
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O objetivo deste estudo prospectivo foi verificar os efeitos dos aparelhos Twin Force Bite Corrector e Forsus Fatigue Resistant Device na junção temporomandibular e nas vias aéreas. Para tanto, foram selecionados 21 pacientes adultos jovens, má oclusão de Classe II 1ª. divisão, bilateral, mínimo de 1/2 Classe II, padrão de crescimento horizontal. Para tanto, a amostra foi dividida em 2 grupos: grupo A, com média de idade inicial de 14,55 anos, tratado com o aparelho ortopédico fixo Twin ForceR por um período médio de 3,7 meses e o grupo B com média de idade inicial de 15,45 anos, tratado com o aparelho Forsus, por um período médio de 7,4 meses, ambos associados à aparelhagem fixa com mecânica straight-wire, prescrição MBT. Os pacientes do grupo A realizaram TCFC em três tempos: T1A (inicial - sem instalação do aparelho), T2A (no dia da i nstalação do aparelho ortopédico fixo), T3A (após a remoção do aparelho ortopédico fixo). Já o grupo 2 realizou TCFC em dois tempos: T2B (no dia da instalação do aparelho ortopédico fixo) e T3B (após a remoção do aparelho ForsusTM). Após a obtenção das imagens 3Dforam realizados cortes sagitais e coronais na ATM para avaliação do tamanho do côndilo e avaliação dos espaços articulares e vias aéreas. Para comparação intergrupos foi utilizado o teste "t" independente e correlação de Pearson e para comparação intragrupos, análise de variância a um critério e teste t pareado. O nível de significância adotado foi de p<0,05%. Não houve alteração significante na avaliação intergrupos, para as dimensões condilares, espaços articulares, e vias aéreas. Por outro lado, na avaliação intragrupo, houve alteração significante no comprimento efetivo da mandíbula (Co-Gn) para o grupo B, supostamente devido a um maior tempo de tratamento, pois houve correlação significante da largura coronal esquerda e direita com Co-Gn, embora clinicamente tenha sido irrelevante. Sendo assim, conclui-se que não houve diferença entre o desempenho dos dois aparelhos estudados na remodelação óssea condilar em pacientes jovens adultos e não houve alteração das vias aéreas após o tratamento com os aparelhos ortopédicos funcionais fixos e Forsus e Twin Force.
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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
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Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.