title: Influence of maxillary advancement surgery on skeletal and soft-tissue changes in the nose - a retrospective cone-beam computed tomography study.
abstract: OBJECTIVE
  Surgical correction of skeletal maxillary retroposition is often associated with changes in the morphology of the nose. Unwanted alar flaring of the nose is observed in many cases. The aim of the present study was therefore to investigate the influence of surgical advancement of the maxilla on changes in the soft-tissue morphology of the nose. Having a coefficient that allows prediction of change in the nasal width in Caucasian patients after surgery would be helpful for treatment planning.
  
  
  METHODS
  All 33 patients included in this retrospective study were of Caucasian descent and had skeletal Class III with maxillary retrognathia. They were all treated with maxillary advancement using a combination of orthodontic and maxillofacial surgery methods. Two cone-beam computed tomography (CBCT) datasets were available for all of the study's participants (16 female, 17 male; age 24.3 ± 10.4 years): the first CBCT imaging was obtained before the planned procedure (T0) and the second 14.1 ± 6.4 months postoperatively (T1). Morphological changes were recorded three-dimensionally using computer-aided methods (Mimics (Materialise NV, Leuven/Belgium), Geomagic (Geomagics, Morrisville/USA)). Statistical analysis was carried out using SPSS 21 for Mac.
  
  
  RESULTS
  The mean sagittal advancement of the maxilla was 5.58 mm. The width of the nose at the alar base (Alb) changed by a mean of + 2.59 mm (±1.26 mm) and at the ala (Al) by a mean of + 3.17 mm (±1.32 mm). Both of these changes were statistically highly significant (P = 0.000). The increase in the width of the nose corresponded to approximately half of the maxillary advancement distance in over 80 % of the patients. The nasolabial angle declined by an average of -6.65° (±7.71°).
  
  
  CONCLUSIONS
  Maxillary advancement correlates with a distinct morphological change in nasal width. This should be taken into account in the treatment approach and in the information provided to patients.
authors.affiliation: Department of Orthodontics, University Hospital, Georg-Voigt-Strasse 3, Marburg, 35039, Germany. hellak@med.uni-marburg.de.
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Hellak
authors.affiliation: Private Practice, Bad Homburg, Germany. bkirsten@t-online.de.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kirsten
authors.affiliation: Department of Orthodontics, University Hospital, Georg-Voigt-Strasse 3, Marburg, 35039, Germany. schausei@med.uni-marburg.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Schauseil
authors.affiliation: Private Practice, Bad Homburg, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Davids
authors.affiliation: Private Practice, Bad Homburg, Germany.
authors.forename: Wolfgang M
authors.initials: WM
authors.lastname: Kater
authors.affiliation: Department of Orthodontics, University Hospital, Georg-Voigt-Strasse 3, Marburg, 35039, Germany. korbmacher@med.uni-marburg.de.
authors.forename: Heike M
authors.initials: HM
authors.lastname: Korbmacher-Steiner
mesh_terms: D000293:Adolescent; D002508:Cephalometry / Q000379:methods; D015331:Cohort Studies; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D019465:Craniofacial Abnormalities / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008437:Maxilla / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000601:surgery*; D056948:Orthognathic Surgical Procedures / Q000379:methods*; D063173:Retrognathia / Q000000981:diagnostic imaging / Q000601:surgery*; D012189:Retrospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome; D055815:Young Adult