title: Short-term and long-term stability of surgically assisted rapid palatal expansion revisited.
abstract: BACKGROUND
  The purpose of this article is to present further longitudinal data for short-term and long-term stability, following up our previous article in the surgery literature with a larger sample and 2 years of stability data.
  
  
  METHODS
  Data from 38 patients enrolled in this prospective study were collected before treatment, at maximum expansion, at removal of the expander 6 months later, before any second surgical phase, at the end of orthodontic treatment, and at the 2-year follow-up, by using posteroanterior cephalograms and dental casts.
  
  
  RESULTS
  With surgically assisted rapid palatal expansion (SARPE), the mean maximum expansion at the first molar was 7.60 ± 1.57 mm, and the mean relapse was 1.83 ± 1.83 mm (24%). Modest relapse after completion of treatment was not statistically significant for all teeth except for the maxillary first molar (0.99 ± 1.1 mm). A significant relationship (P < 0.0001) was observed between the amount of relapse after SARPE and the posttreatment observation. At maximum, a skeletal expansion of 3.58 ± 1.63 mm was obtained, and this was stable.
  
  
  CONCLUSIONS
  Skeletal changes with SARPE were modest but stable. Relapse in dental expansion was almost totally attributed to lingual movement of the posterior teeth; 64% of the patients had more than 2 mm of dental changes. Phase 2 surgery did not affect dental relapse.
authors.affiliation: Department of Orthodontics, University of North Carolina, Chapel Hill, NC, USA. drsylchamberland@biz.videotron.ca
authors.forename: Sylvain
authors.initials: S
authors.lastname: Chamberland
authors.forename: William R
authors.initials: WR
authors.lastname: Proffit
mesh_terms: D000293:Adolescent; D000328:Adult; D001641:Bicuspid / Q000473:pathology; D002508:Cephalometry; D003393:Cranial Sutures / Q000601:surgery; D003481:Cuspid / Q000473:pathology; D003724:Dental Arch / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008334:Mandible / Q000473:pathology; D008437:Maxilla / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D003765:Models, Dental; D008963:Molar / Q000473:pathology; D009296:Nasal Cavity / Q000473:pathology; D009971:Orthodontics, Corrective; D010027:Osteotomy / Q000379:methods; D010155:Palatal Expansion Technique; D011446:Prospective Studies; D012008:Recurrence; D013100:Sphenoid Bone / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult