title: Three-dimensional computed tomographic analysis of changes to the external features of the nose after surgically assisted rapid maxillary expansion and orthodontic treatment: a prospective longitudinal study.
abstract: BACKGROUND
  The aim of this prospective, longitudinal study was to evaluate changes to the external shape and form of the nose after surgically assisted rapid maxillary expansion and orthodontic treatment. The changes were registered using a 3-dimensional computer tomography technique, based on superimposition on the anterior base of the skull.
  
  
  METHODS
  The subjects comprised 35 patients (mean age, 19.7 years; range, 16.1-43.9 years). Low-dose, helical computerized tomography images were taken at treatment start and after orthodontic treatment, about 18 months postsurgery. The 3-dimensional models were registered and superimposed on the anterior cranial base.
  
  
  RESULTS
  There were in general significant widening and overall anterior and inferior displacement of the nasal soft tissues. The changes varied in size and direction. No correlation was found between the initial and final widths of the nose, or between the initial and final widths of the nostrils.
  
  
  CONCLUSIONS
  After surgically assisted rapid maxillary expansion, the most obvious changes to the external features of the nose were at the most lateral alar bases. The difference in lateral displacement profoundly influenced the perception of a more rounded nose. Patients with narrow and constrained nostrils can benefit from these changes. The 3-dimensional superimposition applied in this study is a reliable method, circumventing projection and measurement errors.
authors.affiliation: Department of Orthodontics, Institute for Postgraduate Dental Education, Jönköping, Sweden. anders.magnusson@lj.se
authors.forename: Anders
authors.initials: A
authors.lastname: Magnusson
authors.forename: Krister
authors.initials: K
authors.lastname: Bjerklin
authors.forename: Hyungmin
authors.initials: H
authors.lastname: Kim
authors.forename: Peter
authors.initials: P
authors.lastname: Nilsson
authors.forename: Agneta
authors.initials: A
authors.lastname: Marcusson
mesh_terms: D000293:Adolescent; D000328:Adult; D000814:Aniline Compounds; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla / Q000601:surgery; D008953:Models, Anatomic; D009570:Nitriles; D009666:Nose / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D009971:Orthodontics, Corrective / Q000379:methods*; D010155:Palatal Expansion Technique; D011446:Prospective Studies; D019291:Skull Base / Q000033:anatomy & histology; D018709:Statistics, Nonparametric; D013382:Subtraction Technique; D013536:Suture Techniques; D036542:Tomography, Spiral Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D000814:Aniline Compounds; D009570:Nitriles; C460097:SU 0020