title: Changes in the soft tissue profile after extraction orthodontic therapy.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effects of extraction therapy and use or nonuse of headgear on the soft tissue profile in subjects with different growth patterns.
  
  
  METHODS
  A total of 41 subjects were included in the study. The patients were treated with standard edgewise mechanics and had 4 first premolars extracted. The type of growth pattern was assessed as mesiodivergent or hyperdivergent. The results were analyzed by 2-way analysis of variance.
  
  
  RESULTS
  When comparing the mean changes between growth pattern types, the vertical changes in Sn and A' were found to be statistically significant (P<.05). The vertical change in A' was also found to be significant between the headgear use and nonuse groups (P<.05). Interaction was found to be significant for Steiner upper and lower lip values and the vertical change in A. The upper and lower lips were retracted significantly more by headgear use in patients with hyperdivergent growth pattern (P<.05).
  
  
  CONCLUSIONS
  The results of this study indicate that the use of headgear should be avoided in hyperdivergent patients. The avoidance of premolar extraction, based on the possibility of a significant detrimental effect on the facial profile, is not justified.
authors: Department of Orthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey. darende@gazi.edu.tr
authors: Nilüfer
authors: N
authors: Darendeliler
authors: Lale
authors: L
authors: Taner
mesh_terms: D000293:Adolescent; D000328:Adult; D001641:Bicuspid / Q000601:surgery; D016022:Case-Control Studies; D002508:Cephalometry; D002648:Child; D005115:Extraoral Traction Appliances; D005145:Face / Q000033:anatomy & histology*; D006801:Humans; D008046:Lip / Q000473:pathology; D008311:Malocclusion, Angle Class I / Q000473:pathology / Q000628:therapy; D008312:Malocclusion, Angle Class II / Q000473:pathology / Q000628:therapy; D008334:Mandible / Q000473:pathology; D008437:Maxilla / Q000473:pathology; D008445:Maxillofacial Development / Q000502:physiology*; D009295:Nasal Bone / Q000473:pathology; D012658:Sella Turcica / Q000473:pathology; D012690:Serial Extraction; D014716:Vertical Dimension