H A Schumacher

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Arch guided tooth movement is today still the most often used technique to move teeth bodily in mesiodistal direction. One of the most important disadvantage of this method, however, is friction between bracket and arch wire, which impairs tooth movement and may result in dangerous overload of the anchorage units. Powerhooks are used to accomplish a more(More)
Orthodontic tooth movement along the arch wire is associated with a frictional force between bracket and wire. There is as yet little certainty as to how much force is lost as a result of friction. Therefore a measuring apparatus was used to measure torque in relation to bracket angulation. In all, five types of wire, each of different dimensions were(More)
Fluid and crystallized intelligence are two second-order factors that are differentiated within the intelligence model by R.B.Cattell. Fluid intelligence is considered to be a biological capacity relatively independent of environmental influences. Crystallized intelligence, however, is connected to accultured skills and knowledge. The capacity of fluid(More)
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