98 resultados para INTRUSION


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Purpose We aimed to use lateral and oblique radiographs to evaluate dental and skeletal changes arising from maxillary molar intrusion with zygomatic anchorage in open bite patients. Methods We conducted a pilot study including nine patients (six females and three males; mean age, 18.7±5.1 years) with skeletal open bite treated with titanium miniplates for posterior dentoalveolar intrusion. Lateral and oblique (right and left, 45°) radiographs were obtained before (T1) and 6 months after intrusion (T2). A paired t test was used for statistical evaluation. Results The maxillary posterior teeth were intruded 2.03± 0.87 mm (p<0.01) with 450×g of force, which resulted in counterclockwise rotation of the mandible (1.57°, p=0.02) and clockwise rotation of the occlusal plane (4.27±2.66°, p=0.01). Anterior facial height decreased by a mean of 1.79±1.51 mm (p<0.01). No significant change in the palatal plane or in anteroposterior molar movement was observed. Conclusion The oblique radiograph at 45° was useful for the assessment of molar intrusion and anteroposterior displacement. The treatment of anterior open bite with skeletal anchorage provided intrusion of molars and counterclockwise rotation of the mandible, resulting in open bite closure.

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

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The prevalence of dental trauma and its consequences are challenging. This article presents a clinical case of a 9-year-old female who was in a bicycling accident and had a dental intrusion of the left maxillary lateral incisor with extensive dislocation. In the emergency department, surgical repositioning of the intruded tooth and a splinting with steel wire and composite resin was performed and the soft-tissue lesions were sutured. Two weeks after the first visit, pulp necrosis was found and endodontic treatment of the intruded tooth was started with a calcium hydroxide dressing. Despite the traumatic nature of the dental injury, the result of treatment was favorable. After 3 years of follow-up, repair of the resorptions and no signs of ankylosis of the teeth involved were evident. Considering the patient's age and the extent of intrusion, it was concluded that surgical repositioning associated with adequate endodontic therapy was an effective alternative treatment for this case.

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Purpose: The aim of this research was to assess, by means of, the bi-dimensional finite element method, the best implant location in the alveolar edge, through stress distribution and support structure displacement of a distal extension removable partial denture associated with an osseointegrated implant of 10.0 x .75 mm, acting as abutment for the denture base.Methods and Materials: Five models in sagittal cut were used to represent: model A-hemi arch containing natural tooth 33 and the distal alveolar edge; model B-similar to model A, but with a conventional removable partial denture to replace the absent teeth; model C (MC)-similar to the previous one, with an implant in the distal region of the edge under the denture base; model D-similar to MC, with the implant in the central region of the edge; model E-similar to MC, with an implant in the mesial region of the edge. With the aid of the finite element program ANSYS 8.0, the models were loaded with strictly vertical forces of 50 N on each cusp tip. Displacement and von Mises Maps were plotted for visualization of results.Results: The introduction of implant diminished the tendency of intrusion of the removable partial denture in all situations. The maximum stress was observed on implant in all situations. Approximating implant in direction of support teeth was benefit for stress distribution.Conclusion: Model D presented the lowest value for maximum tendency to displacement when compared with those found in the other models; model E demonstrated better relief with regard to demand from the abutment tooth; locating the implant near of the abutment tooth influenced positively the distribution of stresses on the analyzed structures.

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Intrusion of permanent teeth is one of the most severe types of traumatic injuries. Different treatment strategies have been proposed, and the best approach for each case depends on the stage of root development, severity of the intrusive luxation, presence of alveolar fracture and number of intruded teeth. The purpose of this paper is to describe the treatment management of 2 cases of severely intruded immature permanent maxillary central incisors in 71/2- and 8-year-old children. In case 1, the traumatized tooth was treated by surgical repositioning, while in case 2 watchful waiting for spontaneous re-eruption was the treatment of choice. Treatment strategies were successful in both cases, as demonstrated by the continuation of root development, maintenance of pulp vitality, and absence of signs of per/apical pathosis during the follow-up period. Regardless of the treatment strategy, traumatically intruded teeth should undergo periodical clinical and radiographic surveillance on a long-term basis to allow early detection of possible complications. (Pediotr Dent 2009;31:340-5) Received March 11, 2008 vertical bar Last Revision June 25, 2008 vertical bar Revision Accepted July 16, 2008

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Intrusion is defined as the axial dislodgment of the tooth into its socket and is considered one of the most severe types of dental trauma. This longitudinal outcome study was undertaken to evaluate clinically and radiographically severely intruded permanent incisors in a population of children and adolescents. All cases were treated between September 2003 and February 2008 in a dental trauma service. Clinical and radiographic data were collected from 12 patients (eight males and four females) that represented 15 permanent maxillary incisors. Mean age at the time of injury was 8 years and 9 months (range 7-14 years and 8 months). Mean time elapsed to follow-up was 26.6 months (range 10-51 months). The analysis of data showed that tooth intrusion was twice as frequent in males. The maxillary central incisors were the most commonly intruded teeth (93.3%), and falling at home was the main etiologic factor (60%). More than half of the cases (53.3%) were multiple intrusions, 73.3% of the intruded teeth had incomplete root formation and 66.6% of the teeth suffered other injuries concomitant to intrusion. Immediate surgical repositioning was the treatment of choice in 66.7% of the cases, while watchful waiting for the tooth to return to its pre-injury position was adopted in 33.3% of the cases. The teeth that suffered additional injuries to the intrusive luxation presented a fivefold increased relative risk of developing pulp necrosis. The immature teeth had six times more chances of presenting pulp canal obliteration that the mature teeth and a lower risk of developing root resorption. The most frequent post-injury complications were pulp necrosis (73.3%), marginal bone loss (60%), inflammatory root resorption (40%), pulp canal obliteration (26.7%) and replacement root resorption (20%). From the results of this study, it was not possible to determine whether the type immediate treatment had any influence on the appearance of sequelae like pulp necrosis and root resorption after intrusive luxation, but the existence of additional injuries and the stage of root development influenced the clinical case outcome in a negative and positive manner, respectively.

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Sexual maturity, temporal reproductive pattern, and recruitment of juveniles were examined for the penaeoid shrimp Artemesia longinaris sampled for five and a half years in a tropical locality off the coast of São Paulo (23 degrees S), Brazil. Monthly samples were taken from January 1998 to June 2003 at depths between 5 and 45 m. Ovarian maturity was used to examine breeding in adult females. Recruitment was defined as the percentage of juveniles of the total number of individuals in each month and season. A total of 10 288 females and 5 551 males were collected. Estimated sizes (carapace length) at the onset of sexual maturity were 11.0 mm and 13.4 mm for males and females, respectively. Over the five and a half years, females with ripe gonads were found in every season, with the highest percentages in summer (January-March). Juvenile shrimps occur-red year-round. These results suggest a continuous reproduction of A. longinaris with temperature acting as an environmental stimulus for the duration of the ovary development cycle. These data and the hypothesis of the intrusion of the South Atlantic Central Water mass, which lowered water temperature and raised plankton production, suggest that the end of spring and the beginning of summer were the principal reproductive months. The classical paradigm of continuous reproduction at lower latitudes, with increased seasonality of breeding period at higher latitudes seems to apply to this species.

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Population Structure and reproductive Maturity of females were investigated in the shrimp Artemesia longinaris Bate, 1888 from coastal waters of northern São Paulo State (Brazil. 23 degrees S) and Mar del Plata (Argentina, 38 degrees S) from June 2001 to May 2002. Monthly collections were taken by, commercial shrimp fishing boats equipped with bottom trawl nets. Population parameters from size frequency distributions and size (carapace length = CL) of female reproductive maturity were analyzed and compared front the two sampling areas. Latitudinal trends in reproductive parameters of A. longinaris were shown in overall body size and size of reproductive maturity, both of which were smaller in females from the tropical location than those front the cold-temperate sampling area. Largest females (> 30 turn CL) were collected in Argentina, while Brazilian specimens reached maximum size at 27 nun CL. The smallest Size of female sexual maturity was estimated at 13.6 nun CL in Brazilian samples compared to 22.1 mm CL calculated for those from Argentina. Populations from both regions exhibited a bimodal size distribution in the spring, with the peak at small body size probably corresponding to recent recruits and the peak at larger body, size to reproductive females or shrimps migrating in from deeper waters or other latitudinal regions. In late spring and summer. an intrusion of the cold South Atlantic Coastal Water mass was observed which lowered water temperature and stimulated plankton production. The primary food source for the larvae of a typically cold-temperate species such as A. longinaris. The trend of increasing body size and delay of sexual maturity with increasing latitude appears to be correlated with the decreasing water temperature and increasing plankton productivity at higher latitudes.

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Monazite from chromitites of Cedrolina (Goias State, Brazil) was investigated by electron microprobe and Raman spectroscopy. Monazite has been rarely encountered in chromitites. In Brazil, it was previously reported from chromitites of the Campo Formoso layered intrusion. Comparison between the two occurrences indicates similar morphology and textural characteristics, but remarkable differences in chemical composition. In both cases, monazite occurs as irregular grains (up to 200 mu m) preferentially located in the chlorite-serpentine matrix of the chromitite, more rarely included in chromite. However, the monazite from Cedrolina is characterized by higher Ce/La ratio, and Pr, Nd, Th contents, compared with the monazite from Campo Formoso. The obtained Raman spectra are very similar in the two cases, suggesting that the compositional variation of monazites and the spectral resolution of the Raman do not allow a conclusive chemical analysis with Raman spectra. Textural evidence indicates that, in both occurrences, monazite precipitation did not take place at high temperature, concomitantly with the host chromitite. In the Campo Formoso chromitites, precipitation of monazite has been related with percolation of hydrothermal, aqueous and acid fluids emanating from a granite batholith. on the contrary, the Cedrolina monazite probably formed during one of the metamorphic events that affected the area in which the host chromitite occurs.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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