title: Perception of midline deviations in smile esthetics by laypersons.
abstract: To evaluate the esthetic perception of upper dental midline deviation by laypersons and if adjacent structures influence their judgment.
  An album with 12 randomly distributed frontal view photographs of the smile of a woman with the midline digitally deviated was evaluated by 95 laypersons. The frontal view smiling photograph was modified to create from 1 mm to 5 mm deviations in the upper midline to the left side. The photographs were cropped in two different manners and divided into two groups of six photographs each: group LCN included the lips, chin, and two-thirds of the nose, and group L included the lips only. The laypersons performed the rate of each smile using a visual analog scale (VAS). Wilcoxon test, Student's t-test and Mann-Whitney test were applied, adopting a 5% level of significance.
  Laypersons were able to perceive midline deviations starting at 1 mm. Statistically significant results (p< 0.05) were found for all multiple comparisons of the values in photographs of group LCN and for almost all comparisons in photographs of group L. Comparisons between the photographs of groups LCN and L showed statistically significant values (p< 0.05) when the deviation was 1 mm.
  Laypersons were able to perceive the upper dental midline deviations of 1 mm, and above when the adjacent structures of the smiles were included. Deviations of 2 mm and above when the lips only were included. The visualization of structures adjacent to the smile demonstrated influence on the perception of midline deviation.
authors.affiliation: Master's degree in Orthodontics, Universidade Federal Fluminense, Niterói/RJ, Brazil.
authors.forename: Jamille Barros
authors.initials: JB
authors.lastname: Ferreira
authors.affiliation: Professor, Statistics Department, Universidade Federal Fluminense, Niterói/RJ, Brazil.
authors.forename: Licínio Esmeraldo da
authors.initials: LE
authors.lastname: Silva
authors.affiliation: Professor, Dental Clinics Department, Universidade Federal Fluminense, Niterói/RJ, Brazil.
authors.forename: Márcia Tereza de Oliveira
authors.initials: MT
authors.lastname: Caetano
authors.affiliation: Professor, Dental Clinics Department, Universidade Federal Fluminense, Niterói/RJ, Brazil.
authors.forename: Andrea Fonseca Jardim da
authors.initials: AF
authors.lastname: Motta
authors.affiliation: Professor, Dental Clinics Department, Universidade Federal Fluminense, Niterói/RJ, Brazil.
authors.forename: Adriana de Alcantara
authors.initials: AA
authors.lastname: Cury-Saramago
authors.affiliation: Full professor, Dental Clinics Department, Universidade Federal Fluminense, Niterói/RJ, Brazil.
authors.forename: José Nelson
authors.initials: JN
authors.lastname: Mucha
mesh_terms: D004954:Esthetics / Q000523:psychology*; D005145:Face / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D009055:Mouth / Q000033:anatomy & histology; D010465:Perception; D012904:Smiling / Q000523:psychology; D055815:Young Adult