Adult Nonsurgical Maxillary and Concurrent Mandibular Expansion; Treatment of Maxillary Transverse Deficiency and Bidental Arch Constriction

Nonsurgical expansion of the maxillary transarch width in adults to correct posterior crossbite has been thought to be unsuccessful, unstable, and have undesirable side effects. In the first part of this article, 2 patients with bilateral crossbite who achieved 8-11 mm of maxillary expansion are described. Data from a large sample (47 adults) are reviewed and demonstrate successful and stable expansion with insignificant complications. In the second part of this article, nonsurgical maxillary and concurrent mandibular expansion is used in adults for the correction of constriction of both arches. Associated with arch constriction are incisor crowding, deficient anterior arch contour, dark buccal corridors, and lingual inclination of the posterior dentition. This group of signs is defined as bidental arch constriction syndrome, a common, but not previously described, malocclusion. Two cases demonstrate the malocclusion and its treatment. Data from 30 nonsurgical cases and 10 cases in which both jaws were expanded with surgical distraction are reviewed. There were no significant differences in the expansion achieved, as both expansion techniques were equally effective.