Nonsurgical rapid maxillary alveolar expansion in adults: a clinical evaluation.

Palatal expansion in adults has traditionally been performed on a very limited basis. The expansion has been thought to be limited in scope and stability and to be associated with unacceptable complications. Instead, surgically assisted rapid maxillary expansion (SA-RME) has been advocated. Five adults with transverse arch deficiency are presented to illustrate the feasibility of nonsurgical expansion using the Haas appliance. Transmolar expansions of 3.9 to 7.5 mm, sufficient to correct the malocclusions, were achieved. Limiting the rate of appliance activation is thought to be important to avoid pain, swelling, and ulceration. Measurements of molar axial angulation, facial divergence, and clinical crown heights demonstrated modest molar tipping, stable mandibular divergence, and only minimal gingival recession. Radiographs revealed minimal observable root resorption of the maxillary molars and premolars. Contour tracings of the palate indicated that most of the correction of the maxillary transarch deficiency occurred at the level of the lateral walls of the palate (the alveolar process) rather than in the skeletal base of the maxilla. For this reason the technique is defined as rapid maxillary alveolar expansion (RMAE). RMAE is an acceptable alternative to SA-RME in adults for most cases of maxillary transarch deficiency. This article is followed by a commentary by Robert L. Vanarsdall Jr., and by an author's response.