title: On the relevance of "ideal" occlusion concepts for incisor inclination target definition.
abstract: BACKGROUND
  The concept of "ideal" occlusion in harmony with craniofacial structures is often proposed as an ultimate goal of orthodontic treatment. The aim of this study was to assess the impact of slight variations in posterior occlusion and the history of straight-wire orthodontic treatment on the predictability of incisor inclination and third-order angles.
  
  
  METHODS
  Axial incisor inclinations, third-order angles, and craniofacial relationships were assessed on lateral headfilms and corresponding dental casts of 75 healthy white subjects, 16 to 26 years old, selected by the general inclusion criterion of a good interincisal relationship. Four groups were formed: group A (n = 17), Angle Class I occlusion subjects with no orthodontic treatment; group B (n = 20), Angle Class I occlusion subjects treated with standardized straight-wire orthodontics; group C (n = 20), up to a half-cusp distal occlusion after straight-wire treatment; and group D (n = 18), up to a half-cusp distal occlusion and no orthodontic treatment. Regression analysis was used to insert predictor angles into selected regression equations of the subjects with "ideal" occlusion, and the absolute differences between predicted and observed response angles were determined.
  
  
  RESULTS
  Small differences in incisor inclination were found between subjects with "ideal" occlusion and those who slightly deviated from "ideal" with a mild occlusion of the Angle Class II category. Posterior occlusion was not relevant to the validity of the vast majority of predictor-response pairs. Straight-wire treatment produced incisor inclination that was slightly protruded compared with subjects who had good natural occlusion.
  
  
  CONCLUSIONS
  The "ideal" posterior occlusion concepts as a general orthodontic treatment goal should be reconsidered.
authors: Department of Orthodontics, Dentistry Center, University of Göttingen, Göttingen, Germany. mknoesel@yahoo.de
authors: Michael
authors: M
authors: Knösel
authors: Klaus
authors: K
authors: Jung
mesh_terms: D000293:Adolescent; D000328:Adult; D001641:Bicuspid / Q000473:pathology; D002508:Cephalometry / Q000379:methods*; D002680:Chin / Q000473:pathology; D003766:Dental Occlusion; D005260:Female; D005544:Forecasting; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology*; D008297:Male; D008310:Malocclusion / Q000473:pathology / Q000628:therapy*; 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; D003765:Models, Dental; D008963:Molar / Q000473:pathology; D009295:Nasal Bone / Q000473:pathology; D009969:Orthodontic Wires; D015203:Reproducibility of Results; D012658:Sella Turcica / Q000473:pathology; D014087:Tooth Movement Techniques / Q000379:methods; D055815:Young Adult