title: An internet evaluation of Chinese public preferences for asymmetrically altered incisor angulations.
abstract: OBJECTIVE
  To evaluate the Chinese public preferences for asymmetrically altered incisor angulations, with the goal of linking preferences to gender.
  
  
  METHODS
  Five variations of 5 separate digital smiling photographs were used in this survey. The alterations included discrepancy between the dental and facial midlines, inclination of dental midline and two central incisors, inclination of left central incisor (mesially or distally) and occlusal cant. The raters used a 100-point visual analogue scale to evaluate each image on a web page.
  
  
  RESULTS
  Overall 1,022 raters joined the evaluation and they were reliable (intraclass correlation coefficient = 0.76-0.80). Raters identified range of approval for several smile characteristics. A 2 mm dental to facial midlines discrepancy was the maximum acceptable deviation for females and 3 mm was the maximum for males. Females could accept a 4-degree occlusal cant and males could accept a 6-degree cant. These two characteristics were related to gender. The dental midline and relevant two central incisors with a 5-degree slope or less were generally acceptable. The approval of a left central incisor inclination was 5 degrees mesially and 10 degrees distally. These three characteristics were unrelated to gender.
  
  
  CONCLUSIONS
  The approval for five smile characteristics could be identified reliably. The ranges of acceptability were large and slight changes in the angulations of incisors did not influence the smile attractiveness.
authors.affiliation: Department of Prosthodontics, Peking University School, Beijing, People's Republic of China.
authors.forename: Xiao Qiang
authors.initials: XQ
authors.lastname: Liu
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.forename: Jian Feng
authors.initials: JF
authors.lastname: Zhou
authors.forename: Qin
authors.initials: Q
authors.lastname: Fan
authors.forename: Jian Guo
authors.initials: JG
authors.lastname: Tan
mesh_terms: D000293:Adolescent; D000328:Adult; D001294:Attitude to Health; D002508:Cephalometry / Q000379:methods; D002681:China; D003258:Consumer Behavior; D004955:Esthetics, Dental; D005260:Female; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology*; D020407:Internet; D008297:Male; D008310:Malocclusion / Q000473:pathology / Q000523:psychology; D023861:Photography, Dental; D015203:Reproducibility of Results; D012399:Rotation; D012737:Sex Factors; D012904:Smiling; D055815:Young Adult