title: Assessment of vertical changes during maxillary expansion using quad helix or bonded rapid maxillary expander.
abstract: OBJECTIVE
  To determine if there is a significantly different effect on vertical changes during phase I palatal expansion treatment using a quad helix and a bonded rapid maxillary expander in growing skeletal Class I and Class II patients.
  
  
  METHODS
  This retrospective study looked at 2 treatment groups, a quad helix group and a bonded rapid maxillary expander group, before treatment (T1) and at the completion of phase I treatment (T2). Each treatment group was compared to an untreated predicted growth model. Lateral cephalograms at T1 and T2 were traced and analyzed for changes in vertical dimension.
  
  
  RESULTS
  No differences were found between the treatment groups at T1, but significant differences at T2 were found for convexity, lower facial height, total facial height, facial axis, and Frankfort Mandibular Plane Angle (FMA) variables. A comparison of treatment groups at T2 to their respective untreated predicted growth models found a significant difference for the lower facial height variable in the quad helix group and for the upper first molar to palatal plane (U6-PP) variable in the bonded expander group.
  
  
  CONCLUSIONS
  Overall, both the quad helix expander and the bonded rapid maxillary expander showed minimal vertical changes during palatal expansion treatment. The differences at T2 suggested that the quad helix expander had more control over skeletal vertical measurements. When comparing treatment results to untreated predicted growth values, the quad helix expander appeared to better maintain lower facial height and the bonded rapid maxillary expander appeared to better maintain the maxillary first molar vertical height.
authors.forename: Cara
authors.initials: C
authors.lastname: Conroy-Piskai
authors.forename: Maria Therese S
authors.initials: MT
authors.lastname: Galang-Boquiren
authors.forename: Ales
authors.initials: A
authors.lastname: Obrez
authors.forename: Maria Grace Costa
authors.initials: MG
authors.lastname: Viana
authors.forename: Nelson
authors.initials: N
authors.lastname: Oppermann
authors.forename: Flavio
authors.initials: F
authors.lastname: Sanchez
authors.forename: Bradford
authors.initials: B
authors.lastname: Edgren
authors.forename: Budi
authors.initials: B
authors.lastname: Kusnoto
mesh_terms: D002508:Cephalometry; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla; D010155:Palatal Expansion Technique; D012189:Retrospective Studies; D014716:Vertical Dimension
keywords: Bonded RME; Cephalometric; QuadHelix; Transverse; Vertical