title: Surgically assisted rapid palatal expansion vs. segmental Le Fort I osteotomy: transverse stability over a 2-year period.
abstract: BACKGROUND
  We compared the long-term stability of surgically assisted rapid palatal expansion (SARPE) and segmental Le Fort I osteotomy (bipartition) for expanding the maxillae in adult patients.
  
  
  METHODS
  The upper jaw plaster models of 10 patients who underwent transverse expansion of the maxillae using the SARPE technique and 10 patients who underwent Le Fort I bipartition were examined. For each patient, the intercanine and intermolar distances before expansion (T1), after expansion (T2), and 2 years after expansion (T3) were measured. Consequently, we could evaluate the degree of expansion (between T1 and T2) and the relapse distance after 2 years (between T2 and T3). The palatal stability (i.e., extent of relapse) was used to assess the outcomes in both methods.
  
  
  RESULTS
  In the SARPE group, the average increase in the intercanine and intermolar distance was +8.5 and +7mm, respectively. In the Le Fort I bipartition group, the average respective increase was +2.75 and +3.75mm. Two years after expansion, in the SARPE group, the intercanine distance decreased by 2.5mm or 28% of the overall expansion, and the intermolar distance decreased by 3.0mm or 36% of the overall expansion. In the Le Fort I bipartition group, the intercanine distance decreased by 0.25mm or 25% of the overall expansion, and the intermolar distance decreased by 0.75mm or 20% of the overall expansion.
  
  
  CONCLUSIONS
  In the patients that we assessed, there was a high relapse rate in the mean intercanine and intermolar distances 2 years following the expansion. The overall relapse rate was more pronounced in the SARPE patients, whereas the Le Fort I bipartition technique was more stable, especially in terms of the intermolar distance.
authors.affiliation: Department of Odontostomatological Sciences, University of Bologna, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Marchetti
authors.forename: M
authors.initials: M
authors.lastname: Pironi
authors.forename: A
authors.initials: A
authors.lastname: Bianchi
authors.forename: A
authors.initials: A
authors.lastname: Musci
mesh_terms: D000328:Adult; D002508:Cephalometry; D005260:Female; D006801:Humans; D008297:Male; D019647:Oral Surgical Procedures; D019340:Osteotomy, Le Fort; D017063:Outcome Assessment, Health Care; D010155:Palatal Expansion Technique; D010159:Palate / Q000601:surgery*; D012008:Recurrence; D012189:Retrospective Studies; D055815:Young Adult