This study was undertaken to establish the optimal elastic force for orthodontic tooth movement. The subjects consisted of 25 males and 41 females with malocclusion and of the elastics with different size. The results were obtained.
1) The elastic forces follow the thickness of elastics rather than the diameter. For example, the elastic force follows, 5/16 light, 1/4 light, 5/16 heavy, 1/4 heavy etc.
2) During the initial distal movement of the maxillary canine, 5/16 light and 1/4 light elastics are within the optimal force.
3) During the initial distal movement of the mandible canine, the 5/16 light elastics is choise of selection.
4) 3/16 extra-heavy elastics may cause the great tendency of mesial movement of the anchorage teeth.
|