Closer Look at the Stability of Surgically Assisted Rapid Palatal Expansion

PurposeTo assess the amount of dental and skeletal expansion and stability after surgically assisted rapid maxillary expansion (SARPE).Patients and MethodsData from 20 patients enrolled in this prospective study were collected before treatment, at maximum expansion, at the removal of the expander 6 months later, before any second surgical phase, and at the end of orthodontic treatment, using posteroanterior cephalograms and dental casts.ResultsWith SARPE, the mean maximum expansion at the first molar was 7.48 ± 1.39 mm, and the mean relapse during postsurgical orthodontics was 2.22 ± 1.39 mm (30%). At maximum, a 3.49 ± 1.37 mm skeletal expansion was obtained, and this expansion was stable, such that the average net expansion was 67% skeletal.ConclusionClinicians should anticipate a loss of about one third of the transverse dental expansion obtained with SARPE, although the skeletal expansion is quite stable. The amount of postsurgical relapse with SARPE appears quite similar to the changes in dental-arch dimensions after nonsurgical rapid palatal expansion, and also quite similar to dental-arch changes after segmental maxillary osteotomy for expansion.