title: Rapid palatal expansion effects on nasal airway dimensions as measured by acoustic rhinometry. A systematic review.
abstract: OBJECTIVE
  To evaluate available information on the effects of rapid maxillary expansion on nasal airway minimal cross-sectional area and volume, as measured by acoustic rhinometry.
  
  
  METHODS
  An electronic database search was conducted. Based on abstracts/titles, articles were initially selected; then full articles were retrieved and were further sorted according to secondary, more stringent criteria. References from selected articles were hand-searched for potential missed publications. Clinical trials using acoustic rhinometry on subjects undergoing rapid maxillary expansion therapy were included. Syndromic or medically compromised patients and absence of an untreated control group were reasons for exclusion. Selected studies thereafter were evaluated methodologically.
  
  
  RESULTS
  Only four articles reached final selection, and their overall methodology scores were low, limiting the applicability of results. After rapid maxillary expansion, three of four studies found statistically significant increases in minimal cross-sectional area, and two of three studies reported statistically significant increases in nasal cavity volume as compared with control groups. It appears that any increase is less stable if a traditional technique is used on patients who have passed their peak growth spurt.
  
  
  CONCLUSIONS
  Although some increases in nasal dimensions have been reported, the changes in nasal volume were small and should not be presented to patients as a clinically significant indication for therapeutic maxillary expansion.
authors.affiliation: Orthodontic Graduate Program, Department of Dentistry, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Jillian M
authors.initials: JM
authors.lastname: Gordon
authors.forename: Mark
authors.initials: M
authors.lastname: Rosenblatt
authors.forename: Manisha
authors.initials: M
authors.lastname: Witmans
authors.forename: Jason P
authors.initials: JP
authors.lastname: Carey
authors.forename: Giseon
authors.initials: G
authors.lastname: Heo
authors.forename: Paul W
authors.initials: PW
authors.lastname: Major
authors.forename: Carlos
authors.initials: C
authors.lastname: Flores-Mir
mesh_terms: D056151:Airway Remodeling; D006801:Humans; D009296:Nasal Cavity / Q000033:anatomy & histology*; D010155:Palatal Expansion Technique; D023842:Rhinometry, Acoustic