title: Prevalence of alterations in the characteristics of smile symmetry in an adult population from southern Europe.
abstract: BACKGROUND
  Deviation from the facial midline and inclination of the dental midline or occlusal plane has been described as extremely influential in the layperson's perceptions of the overall esthetics of the smile.
  
  
  OBJECTIVE
  The purpose of this study was to determine the prevalence of deviation from the facial midline and inclination of the dental midline or occlusal plane in a selected sample.
  
  
  METHODS
  White participants from a European population (N=158; 93 women, 65 men) who met specific inclusion criteria were selected for the present study. Standardized 1:1 scale frontal photographs were made, and 3 variables of all participants were measured: midline deviation, midline inclination, and inclination of the occlusal plane. Software was used to measure midline deviation and inclination, taking the bipupillary line and the facial midline as references. Tests for normality of the sample were explored and descriptive statistics (means ±SD) were calculated. The chi-square test was used to evaluate differences in midline deviation, midline inclination, and occlusion plane (α=.05) RESULTS: Frequencies of midline deviation (>2 mm), midline inclination (>3.5 degrees), and occlusal plane inclination (>2 degrees) were 31.64% (mean 2.7±1.23 mm), 10.75% (mean 7.9 degrees ±3.57), and 25.9% (mean 9.07 degrees ±3.16), respectively. No statistically significant differences (P>.05) were found between sex and any of the esthetic smile values.
  
  
  CONCLUSIONS
  The incidence of alterations with at least 1 altered parameter that affected smile esthetics was 51.9% in a population from southern Europe.
authors.affiliation: Dentistry Department, University of Seville, Seville, Spain. Electronic address: ejcb@us.es.
authors.forename: Emilio
authors.initials: E
authors.lastname: Jiménez-Castellanos
authors.affiliation: Associate Professor, Dentistry Department, University of Seville, Seville, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Orozco-Varo
authors.affiliation: Associate Professor, Dentistry Department, University of Seville, Seville, Spain.
authors.forename: Gema
authors.initials: G
authors.lastname: Arroyo-Cruz
authors.affiliation: Associate Professor, Department Stomatology IV, Complutense University of Madrid, Madrid, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Iglesias-Linares
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003766:Dental Occlusion; D004955:Esthetics, Dental; D005145:Face / Q000033:anatomy & histology; D005146:Facial Asymmetry / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010780:Photogrammetry / Q000379:methods; D015995:Prevalence; D012904:Smiling; D013030:Spain / Q000453:epidemiology; D055815:Young Adult