BIOMECHANICAL BASIS OF VERTICAL DIMENSION CONTROL DURING RAPID PALATAL EXPANSION THERAPY

Rapid palatal expansion (RPE) is recognized as a very successful ortho pedic therapy to correct maxillary transverse deficiencies in growing patients. However, the transverse forces delivered during RPE have bee n shown to create undesirable orthodontic and orthopedic side effects in patients exhibiting skeletal open bite tendency, large interlabial gap, or severe Class II skeletal patterns, with long lower facial heig ht and increased facial convexity. The application of extraoral forces during RPE therapy by the concomitant use of a high-pull chincap is d escribed and clinically illustrated as a method to control the vertica l dimension.