title: Effects of orthodontic treatment and premolar extractions on the mandibular third molars.
abstract: BACKGROUND
  The space available for an unerupted mandibular third may depend on the choice of premolar extracted.
  
  
  OBJECTIVE
  To investigate the effects of orthodontic treatment and premolar extractions on the inclinations of the mandibular third molars and the space available for their eruption, and to compare these changes with a nonextraction group.
  
  
  METHODS
  The pre- and post-treatment panoramic radiographs of 54 subjects (20 males, 34 females) were used. Eighteen of these subjects had the four first premolars extracted, 16 subjects had four second premolars extracted and 20 subjects were treated nonextraction. Changes in the inclinations and spaces available for the unerupted third molars were compared.
  
  
  RESULTS
  In the nonextraction group the third molars uprighted approximately 1 degree and in the second premolar extraction group the third molars uprighted 10 degrees. The spaces available for the third molars increased significantly in the first and second premolar extraction groups as compared with the space available in the nonextraction group.
  
  
  CONCLUSIONS
  Orthodontic treatment and extraction of the second premolars improved the inclinations of unerupted third molars and the space available for their eruption into the arch. The changes in inclination and eruption space were less marked following first premolar extractions.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey. mevlutcelikoglu@hotmail.com
authors.forename: Mevlut
authors.initials: M
authors.lastname: Celikoglu
authors.forename: Hasan
authors.initials: H
authors.lastname: Kamak
authors.forename: Ismail
authors.initials: I
authors.lastname: Akkast
authors.forename: Hüsamettin
authors.initials: H
authors.lastname: Oktay
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000601:surgery*; D016022:Case-Control Studies; D002508:Cephalometry / Q000379:methods; D003724:Dental Arch / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy; D008334:Mandible / Q000473:pathology*; D008964:Molar, Third / Q000503:physiopathology*; D011862:Radiography, Panoramic; D012189:Retrospective Studies; D012690:Serial Extraction; D014078:Tooth Eruption / Q000502:physiology; D014087:Tooth Movement Techniques / Q000379:methods*; D014097:Tooth, Unerupted / Q000503:physiopathology*