Abordagens da biomecânica ortodôntica utilizando mini-implantes

As an innovative transitory anchorage device, the mini-implants deserve to be described with details regarding its use and action during orthodontic treatment. Therefore, this paper intents to present some biomechanic criteria adopted to for a better use of mini-implants as anchorage in anterior retraction (space closure), molar distalization, mesial movement of the molars, intrusion of molars and as support to provisional implant.

Alternativa de tratamento simplificado e integrado da retenção intraóssea de incisivo central superior, associada a odontoma: relato de caso

Permanent teeth impaction is highly prevalent among brazilian people. Its etiology is related to local and general factors association. Permanent teeth retention compromises dental occlusion and when anterior teeth are involved, it also brings esthetics impairments which lead to psychological disturbance. Early diagnosis and adequate treatment are extremely important to solve not only occlusal problems but also psychological aspects. Orthodontic traction of impacted teeth can be conducted by using fixed or removable appliances. Although it depends on patient compliance the use of removable appliances provides an anchorage based on the teeth and the palate reducing undesirable side effects. This paper describes the case of a fourteen years old female patient whose right maxillary central incisor was adequately tractioned with a removable orthodontic appliance. Removable orthodontic devices were used at first to reposition teeth in maxillary anterior area what provided adequate space to allow the placement of the impacted incisor and after were also used to traction and position this tooth. The procedure described seemed to be effective, non expensive and a viable treatment to be performed even on the scope of public health services, extending orthodontic treatment to a higher number of patients.

Bone stress and strain after use of a miniplate for molar protraction and uprighting: a 3-dimensional finite element analysis

The aim of this study was to use the finite element method to evaluate the distribution of stresses and strains on the local bone tissue adjacent to the miniplate used for anchorage of orthodontic forces. Methods: A 3-dimensional model composed of a hemimandible and teeth was constructed using dental computed tomographic images, in which we assembled a miniplate with fixation screws. The uprighting and mesial movements of the mandibular second molar that was anchored with the miniplate were simulated. The miniplate was loaded with horizontal forces of 2, 5, and 15 N. A moment of 11.77 N.mm was also applied. The stress and strain distributions were analyzed, and their correlations with the bone remodeling criteria and miniplate stability were assessed. Results: When orthodontic loads were applied, peak bone strain remained within the range of bone homeostasis (100-1500 mu m strain) with a balance between bone formation and resorption. The maximum deformation was found to be 1035 mu m strain with a force of 5 N. At a force of 15 N, bone resorption was observed in the region of the screws. Conclusions: We observed more stress concentration around the screws than in the cancellous bone. The levels of stress and strain increased when the force was increased but remained within physiologic levels. The anchorage system of miniplate and screws could withstand the orthodontic forces, which did not affect the stability of the miniplate.

Camuflagem ortodôntica com dispositivos de ancoragem temporários ou cirurgia ortognática: parâmetros para a decisão

The polemical discussion between orthodontic therapeutic and surgical approaches with relation to borderline cases receives a new impulse with the emergence of temporary anchorage devices. This branch of Orthodontics has brought new treatment perspectives, but it has still been applied empirically, while the various factors involved in determining and conducting the treatment planning are neglected. The objective of the present study is to identify the several factors to be considered in both forms of treatment in order to provide the orthodontist with information that may contribute for the correct decision.

Confecção e montagem do set-up ortodôntico

Diagnosis and planning stages are critical to the success of orthodontic treatment, in which the orthodontist should have many elements that contribute to the most appropriate decision-making. The orthodontic set-up is an important resource in the planning of corrective orthodontics therapy. It consists of the repositioning of the teeth previously removed from the study dental casts and reassembled on its remaining basis. When properly made, the set-up allows a three-dimensional preview of problems and limitations of the case, assisting in decision-making regarding tooth extractions in cases with problems of space, amount of anchorage loss extent and type of tooth movement, discrepancy of dental arch perimeter, discrepancy of inter-arch tooth volume, among others, indicating the best option for treatment. This paper outlines the most important steps for its confection, an evaluation system and its application in the preparation of orthodontic treatment planning.

Montagem e confecção do set up ortodôntico

Diagnosis and planning stages are critical to the success of orthodontic treatment, in which the orthodontist should have many elements that contribute to the most appropriate decision-making. The orthodontic set-up is an important resource in the planning of corrective orthodontics therapy. It consists of the repositioning of the teeth previously removed from the study dental casts and reassembled on its remaining basis. When properly made, the set-up allows a three-dimensional preview of problems and limitations of the case, assisting in decision-making regarding tooth extractions in cases with problems of space, amount of anchorage loss extent and type of tooth movement, discrepancy of dental arch perimeter, discrepancy of inter-arch tooth volume, among others, indicating the best option for treatment. This paper outlines the most important steps for its confection, an evaluation system and its application in the preparation of orthodontic treatment planning.

Necessidade de ancoragem do grupo A e o controle biomecanico da mola T pré-ativada por curvatura para o fechamento de espacos

Contemporary orthodontics has sought, beyond the esthetic, occlusal and functional goals, treatments even faster and with less visits to the orthodontist — especially in patients that require dental extractions in which the generated space becomes a nuisance. The segmented arch technic (SAT), by the use of a "T" loop spring, has provided such results within these requirements. Therefore, this study aimed to appraise and demonstrate the confection, activation and biomechanical control of "T" loop spring, in the group with high anchorage necessity (group A), for retraction of anterior teeth; as well as to present a case report, with high anterior retraction necessity, treated with "T" loop spring.

Estudio del espesor de la mucosa del trígono retromolar con el objetivo de facilitar la planificación de mini implantes en la región

The retromolar triangle is a triangular area located in the mandible, posteriorly to the last molar. This region, due its thickness and bone density, is widely used for the installation of devices that provide an anchorage system for the movement of the lower molars. The aim of this research is to provide morphometric data of the mucosa thickness of the retromolar triangle. Twenty-five patients of portuguese nationality, with indication for extraction of the impacted lower third molar (right and/or left), were studied. In the region of the retromolar triangle were demarcated 3 points corresponding to the vertices of a triangle whose the base was torned for the distal face of the lower third molar and the lenght of the sides corresponded to vestibulolingual dimension of the same tooth, then was demarcated a fourth point corresponding to the geometric center of the triangle. Then, using a finger spreader with silicone stop were measured the mucosal tickness at each point. The data obtained were tabulated and analyzed. The lowest average value found was 5.5mm on the right side and the highest average value found was 7.13mm on the left side. Considering the mean values obtained at the points of the retromolar triangle mucosa measured in this study, we conclude that the retromolar triangle shows thick mucosa, so the mini-implants indicated for this region should have a long transmucosal neck.

Chemical analysis and Vickers hardness of orthodontic mini-implants

Orthodontic mini-implants are used in clinical practice to provide efficient and aesthetically-pleasing anchorage. AIM: To evaluate the hardness Vickers hardness and chemical composition of mini-implant titanium alloys from five commercial brands. METHODS: Thirty self-drilling mini-implants, six each from the following commercial brands, were used: Neodent NEO, Morelli MOR, Sin SIN, Conexão CON, and Rocky Mountain RMO. The hardness and chemical composition of the titanium alloys were performed by the Vickers hardness test and energy dispersive X-ray spectroscopy, respectively. RESULTS: Vickers hardness was significantly higher in SIN implants than in NEO, MOR, and CON implants. Similarly, VH was significantly higher in RMO implants than in MOR and NEO ones. In addition, VH was higher in CON implants than in NEO ones. There were no significant differences in the proportions of titanium and aluminum in the mini-implant alloy of the five commercial brands. Conversely, the proportion of vanadium differed significantly between CON and MOR/NEO implants. CONCLUSIONS: Mini-implants of different brands presented distinct properties of hardness and composition of the alloy.

Immunoexpression of ROCK-1 and MMP-9 as prognostic markers in breast cancer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modificação de superfície da liga Ti6A14V para apliacação biomédica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tratamento de superfície de implantes dentários: SBF

Various surface treatments of dental implants have been developed in order to ensure anchorage to bone tissue, optimization of the determinants of electronic structure, crystallinity, composition and properties. Coating techniques have been proposed in order tocreate unionbiochemicalable to accelerate the early stages ofbone tissue, combining the positive properties of titanium and its alloys bioactivity of ceramic materials. This paper discusses protocol for handling the SBF coating of titanium alloys. The apatite phase nucleation occurs by immersing the substrate in synthetic solution simulating blood plasma (Simulated Body Fluid). The protocol allows manipulation of the SBF solution to establish guidelines regarding the usestreamlinedand organized to make practical application.

Protocolo radiográfico para a instalação de mini-implantes: descrição da técnica

In the last decade mini-screws have gained popularity in orthodontics field and a correct placement of mini-screws is a critical point to the success of the skeletal anchorage. A careful clinical and radiographic diagnostic before insertion mini-screw is an essential requirement to achieve the central point of the radicular septum. The correct application of these pre-surgical procedures should avoid possible iatrogenic damages in periodontal ligament, dental roots, nasomaxillary cavities, or even important vascular tissues. As of today, periapical radiographs is a regular pre surgical procedure during mini-screw insertion technique. Nevertheless, accurate execution of the radiographic parallax technique can offer to us useful and precise radiographic images, to decide the right local insertion of mini-screws in to the septum bone. The purpose of this paper is to describe the ¬application of new positioning circular guides in conjunction with a ¬parallax radiographic protocol before placement of orthodontic mini-screws.

Estruturas de concreto reforçadas com PRFC parte II: análise dos modelos de cisalhamento

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação da ação da melatonina em células-tronco tumorais mamárias RE-positivas tratadas com disruptores estrogênicos: verificação da via do receptor de estrógeno mediada pelo gene OCT 4

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)