Expansion: Lessons From The Lab

Many patients have a narrow maxillary arch. Often this requires widening to relieve crowding and provide more pleasing facial contours. Expansion appliances can widen the maxillary arch in two different ways. Teeth can be moved in a lateral direction (dental expansion) or the palate can be widened along the median palatal suture (orthopedic expansion).

In pre-adolescents, the two halves of the palate have not yet fused together, so permanent widening of the palate is a relatively simple process. When lateral pressure is applied, the two halves push apart. New bone rapidly grows between the two plates making the expansion permanent. Here are a few of the most common expander designs: