Review on the Skeletal Effects of Rapid Palatal Expansion in Late Mixed Dentition

Abstract

Introduction: Rapid palatal expansion is utilized in Orthodontics to treat maxillary transverse deficiencies. Such deficiencies can cause functional defects, misalignments, and mandibular shifts that can impact one’s function, comfort, and quality of life. This review aimed to synthesize the clinical findings of rapid palatal expanders. Methods: A literature search of skeletal effects of maxillary rapid palatal expansion was performed using PubMed and Google Scholar. Inclusion criteria consisted of studies that measured changes in maxillary width over at least one year of expansion and retention or radiographic confirmation of skeletal expansion with a sample size of over 15 subjects. Exclusion criteria were subjects with developmental defects, such as cleft palate, or any type of surgical assisted rapid palatal expansion. A total of 12 articles were found from January 1990 to April 2022 and included in this review. Results: All 12 articles reported that rapid palatal expansion notably increases the maxillary skeletal transversal dimension. Across all studies, the amount of intercanine expansion from rapid palatal expansion ranged from 2.5 to 4.0 mm, and the amount of intermolar expansion ranged from 3.9 to 6.5 mm. The studies also showed a significant expansion of nasal cavity (airway), various facial sutures being affected, occurrence of buccal tipping of all maxillary teeth, mandibular spacing being gained, and that relapse, although present, had an insignificant effect on the long-term retention of expansion. Conclusion: Rapid palatal expanders are effective in producing both immediate and long-term transverse expansion in subjects in late mixed dentition.