Simulation is an important tool when training is hazardous, time consuming, or expensive. Simulation can also be used to enhance reality by adding features normally not available in the real world. The aim with this work has been to develop and evaluate methods that could improve learning in oral radiology utilising a radiation-free simulator environment. Virtual reality software for radiographic examinations was developed. The virtual environment consisted of a model of a patient, an x-ray machine, and a film. Simulated radiographic images of the patient model could be rendered as perspective projections based on the relative position between the individual models. The software was incorporated in an oral radiology simulator with a training program for interpretation of spatial relations in radiographs. Projection geometry was validated by comparing length dimensions in simulated radiographs with the corresponding theoretically calculated distances. The results showed that projection error in the simulated images never exceeded 0.5 mm. Dental students participated in studies on skill in interpreting spatial information in radiographs utilising parallax. Conventional and simulator based training methods were used. Training lasted for 90 minutes. Skill in interpreting spatial information was assessed with a proficiency test before training, immediately after training, and eight months after training. Visual-spatial ability was assessed with mental rotations test, version A (MRT-A). Regression analysis revealed a significant (P<0.01) association between visual-spatial ability and proficiency test results after training. At simulator training, proficiency test results immediately after training were significantly higher than before training (P<0.01). Among students with low MTR-A scores, improvement after simulator training was higher than after conventional training. Eight months after simulator training proficiency test results were lower than immediately after training. The test results were, however, still higher than before training. In conclusion, the simulation software produces simulated radiographs of high geometric accuracy. Acquisition of skill to interpret spatial relations in radiographs is facilitated for individuals with high visual-spatial ability. Simulator training improves acquisition of interpretative skill and is especially beneficial for individuals with low visual-spatial ability. The results indicate that radiology simulation can be an effective training method.

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Made available in DSpace on 2016-03-15T19:39:52Z (GMT). No. of bitstreams: 1 Jose Ricardo Lemes de Almeida.pdf: 10266228 bytes, checksum: 65b1cb994ef14d0ca73bd5cbfa547e03 (MD5) Previous issue date: 2011-02-07 / One of the difficulties in teaching Chemistry is establishing relationships between representations of the microscopic and the macroscopic levels while exploring a concept. Earlier studies have shown that the use of computer or physical visualization tools result in a more efficient learning of these concepts. It is believed that part of the positive effect is related to training visual-spatial abilities. Based on these studies, this research sought to investigate the impact of an educational intervention on the accomplishments of tasks that measure visual-spatial abilities. A group of 56 students paired by gender was divided randomly into two groups. One of the groups received an educational intervention using a kit for building a tetrahedron; the other group received a list of exercises of molecular geometry. To evaluate the effects of the proposed intervention, students were asked to take part of two mental rotation tests of three dimensional images after each intervention. In one of them, the stimuli were images of molecules, and in the other they were solid three dimensional objects; the images appeared at different rotations on a computer screen. The task was to say the name of the molecules and, in the case of the objects, compare them to other objects that had not been rotated. The tests were applied using equipment that registers eye movements (Tobii® 1750). The analysis was based on response time, right answers, wrong answers, and strategies of eye movement to follow stimuli. The main results showed a larger number of right answers in the group that used the kit, both in the test with images of molecules and in the test of geometric objects. These results lead us to believe that the kit was effective for the visualization of molecules, becoming an important teaching tool in Chemistry. Besides, the effect of the kit in tests of three dimensional objects pointed out to the positive impact that this strategy had on the visual-spatial abilities in general. / Uma das dificuldades encontradas no ensino da Química é o estabelecimento de relações entre representações do nível microscópico e as do macroscópico na exploração de um conceito. Estudos anteriores mostraram que a utilização de ferramentas de visualização computacional ou física resulta em aprendizado mais efetivo de conceitos. Acredita-se que parte do efeito positivo deva estar relacionada a um treinamento de habilidades visoespaciais. Para verificar essa hipótese, um grupo de 56 alunos pareados por gênero foi dividido aleatoriamente em dois grupos. Um dos grupos recebeu intervenção educacional com o kit de montagem física de um tetraedro; o outro recebeu uma lista de exercícios de geometria molecular. Para a avaliação dos efeitos das intervenções propostas, após essas intervenções os alunos realizaram testes de rotação mental de figuras tridimensionais. Em um deles, os estímulos eram figuras de moléculas e, no outro, eram objetos sólidos tridimensionais; as figuras apareciam rotacionadas em uma tela de computador. A tarefa era dizer o nome das moléculas e, no caso dos objetos, compará-los com outros objetos não rotacionados. Os testes foram realizados em equipamento de registro dos movimentos oculares (Tobii® 1750). Foram analisados o tempo de resposta, o número de acertos e erros, e as estratégias visuais de rastreio dos estímulos. Os resultados sinalizaram que o uso do kit foi efetivo para melhor visualização de moléculas, o que o caracterizou como importante ferramenta no ensino-aprendizagem de Química. Além disso, o efeito do kit em testes de figuras tridimensionais apontou para o impacto positivo que esta estratégia teve nas habilidades visoespaciais de forma geral.