title: Profile changes of patients treated with and without premolar extractions.
abstract: BACKGROUND
  In this study, we evaluated and compared treatment effects and long-term soft-tissue profile changes in patients treated with extraction of 4 first premolars and with a nonextraction protocol.
  
  
  METHODS
  Cephalometric records of 98 patients were evaluated. For half (n = 49) of the patients, treatment included the extraction of 4 first premolars; the other 49 patients had no premolar extractions. The groups were evaluated before treatment (T1), at the end of treatment (T2), and at least 4 years postretention (T3).
  
  
  RESULTS
  At T1, the extraction group had more protrusive lower lips than the nonextraction group, as measured by the Z-angle. At T2, the Z-angles had improved in both groups and were not significantly different. During treatment, upper lip vermilion and superior thicknesses increased, whereas lower lip vermilion thickness decreased in both groups. Except for lower lip inferior thickness, which increased significantly in the nonextraction group, no other soft-tissue differences were significant. Significant growth of the nose occurred during from T1 to T2 in both groups, and there was a tendency for the incisors in both groups to return to pretreatment values. The nose also continued to grow during that period.
  
  
  CONCLUSIONS
  Overall, the soft-tissue facial profile measurements for both extraction and nonextraction samples were similar at T3, and there were no clinically significant correlations between hard- and soft-tissue variables at T1, T2, and T3.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, University of Ege, Ege, Turkey.
authors.forename: Aslihan Ertan
authors.initials: AE
authors.lastname: Erdinc
authors.forename: Ram S
authors.initials: RS
authors.lastname: Nanda
authors.forename: Tarisai C
authors.initials: TC
authors.lastname: Dandajena
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001641:Bicuspid / Q000601:surgery; D002508:Cephalometry / Q000706:statistics & numerical data; D002648:Child; D004955:Esthetics, Dental; D005145:Face / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D009971:Orthodontics, Corrective / Q000379:methods*; D012189:Retrospective Studies; D014081:Tooth Extraction; D016896:Treatment Outcome