| 摘要 |
In an orthodontic tooth positioning appliance of the type wherein all teeth normally engage the isthmus of the tooth receiving troughs substantially concurrently, the thickness of the isthmus is either (a) increased at the anterior teeth, relative to the thickness at the posterior teeth, for correcting or preventing relapse of a correction for overbite or (b) decreased at the anterior teeth, relative to the thickness at the posterior teeth to correct for or prevent relapse of a correction for open bite. |
