title: Changes in soft tissue nasal widths associated with rapid maxillary expansion in prepubertal and postpubertal subjects.
abstract: OBJECTIVE
  To evaluate changes in the soft tissue width of the nose induced by rapid maxillary expansion (RME). Data on greater alar cartilage (GAC) and alar base (AB) widths were compared with a normative sample within the same age range.
  
  
  METHODS
  This prospective study consisted of an RME sample of 79 patients treated with an RME protocol. Mean age at the start of RME treatment was 13.5 years; average duration of treatment was 6.7 months. Patients were grouped into prepubertal and postpubertal groups based on their cervical vertebral maturation (CVM) stage. AB and GAC widths were determined at three separate time points. The normative sample consisted of 437 orthodontically untreated whites, aged 10-16 years. A repeated measures analysis of variance (ANOVA) was used to determine group differences. In addition, independent sample t-tests were used to compare posttreatment nasal width values vs the untreated normative sample.
  
  
  RESULTS
  Increases in AB and GAC widths of the nose in the RME sample were less than 1.5 mm. No significant differences were noted in width changes between the prepubertal and postpubertal subgroups. Comparisons of T3 values showed that on average nasal width increases were greater in the RME group than in untreated norms by 1.7 mm for the GAC measure (statistically significant), and by less than 1 mm for the AB measure.
  
  
  CONCLUSIONS
  RME has no significant clinical effects on the widths of the apical base and the greater alar cartilage of the nose; no differences were observed between the two maturational subgroups.
authors.affiliation: The University of Michigan, Ann Arbor, MI, USA.
authors.forename: Bret M
authors.initials: BM
authors.lastname: Johnson
authors.forename: James A
authors.initials: JA
authors.lastname: McNamara
authors.forename: Roger L
authors.initials: RL
authors.lastname: Bandeen
authors.forename: Tiziano
authors.initials: T
authors.lastname: Baccetti
mesh_terms: D000293:Adolescent; D000365:Age Determination by Skeleton; D000704:Analysis of Variance; D016022:Case-Control Studies; D002508:Cephalometry; D002574:Cervical Vertebrae / Q000254:growth & development; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D055171:Nasal Cartilages / Q000033:anatomy & histology; D009666:Nose / Q000033:anatomy & histology*; D010155:Palatal Expansion Technique; D011446:Prospective Studies; D011627:Puberty; D012016:Reference Values