title: Esthetic impact of premolar extraction and nonextraction treatments on Korean borderline patients.
abstract: BACKGROUND
  The esthetic impact of the soft-tissue profile might play a major role in deciding on premolar extraction or nonextraction treatment, particularly in borderline patients. The purpose of this study was to compare the esthetic impact of extraction and nonextraction therapy on Korean patients.
  
  
  METHODS
  Panels of 50 dentists and 50 laypersons evaluated randomly presented pretreatment and posttreatment soft-tissue profiles of 50 extraction and 50 nonextraction patients. As subjects in this study, borderline patients were selected based on their initial diagnostic records. Two panels were asked to compare the pretreatment and posttreatment profile tracings and to quantify their perceptions of the esthetic impact of treatment change using a visual analog scale.
  
  
  RESULTS
  Premolar extraction patients showed greater improvement in facial profile compared with nonextraction patients, regardless of the panel. Based on the results of regression analysis to determine the degree of lip protrusion at which the retraction that commonly follows premolar extraction would be needed, the intersection was about 3.0 mm behind the Ricketts' E-line; this is far behind the Korean norm.
  
  
  CONCLUSIONS
  The results indicate that premolar extraction is more beneficial than nonextraction treatment in terms of facial profile improvement in Korean borderline patients.
authors.affiliation: Department of Orthodontics, 2nd Stage of Brain Korea 21, School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju, Korea.
authors.forename: Hoi-Jeong
authors.initials: HJ
authors.lastname: Lim
authors.forename: Kwang-Taek
authors.initials: KT
authors.lastname: Ko
authors.forename: Hyeon-Shik
authors.initials: HS
authors.lastname: Hwang
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D044466:Asian People; D001641:Bicuspid / Q000601:surgery; D002648:Child; D003815:Dentists / Q000523:psychology; D004955:Esthetics, Dental; D005145:Face / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007723:Korea; D016014:Linear Models; D008046:Lip / Q000033:anatomy & histology; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D009971:Orthodontics, Corrective / Q000379:methods*; D011639:Public Opinion; D014081:Tooth Extraction; D016896:Treatment Outcome