title: Esthetic Assessment of the Effect of Gingival Exposure in the Smile of Patients with Unilateral and Bilateral Maxillary Incisor Agenesis.
abstract: OBJECTIVE
  The aim of this study was to determine the dental esthetic perception of the smile of patients with maxillary lateral incisor agenesis (MLIA); the perceptions were examined pre- and post-treatment. Esthetic determinations were made with regard to the gingival exposure in the patients' smile by orthodontists, general dentists, and laypersons.
  
  
  METHODS
  Three hundred eighty one people (80 orthodontists, 181 general dentists, 120 laypersons) rated the attractiveness of the smile in four cases before and after treatment, comprising two cases with unilateral MLIA and contralateral microdontia and two with bilateral MLIA. For each case, the buccal photograph was adjusted using a computer to apply standard lips to create high, medium, and low smiles. A numeric scale was used to measure the esthetic rating perceived by the judges. The resulting arithmetic means were compared using an ANOVA test, a linear trend, and a Student's t-test, applying a significance level of p < 0.05. The predictive capability of the variables, unilateral, or bilateral MLIA, symmetry of the treatment, gingival exposure of the smile, group, and gender were assessed using a multivariable linear regression model.
  
  
  RESULTS
  In the pre- and post-treatment cases, medium smile photographs received higher scores than the same cases with high or low smiles, with significant differences between them. In all cases, orthodontists were the least-tolerant evaluation group (assigning lowest scores), followed by general dentists. In a predictive linear regression model, bilateral MLIA was the more predictive variable in pretreatment cases. The gingival exposure of the smile was a predictive variable in post-treatment cases only.
  
  
  CONCLUSIONS
  The medium-height smile was considered to be more attractive. In all cases, orthodontists gave the lowest scores, followed by general dentists. Laypersons and male evaluators gave the highest scores. Symmetrical treatments scored higher than asymmetrical treatments. The gingival exposure had a significant influence on the esthetic perception of smiles in post-treatment cases.
authors.affiliation: Instituto Superior de Ciências da Saúde-Norte, CESPU, Instituto de Investigacão e Formação Avançada em Ciências e Tecnologias da Saúde (IINFACTS), Gandra PRD, Portugal.
authors.forename: Teresa
authors.initials: T
authors.lastname: Pinho
authors.affiliation: Stomatology Department, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Bellot-Arcís
authors.affiliation: Stomatology Department, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain.
authors.forename: José María
authors.initials: JM
authors.lastname: Montiel-Company
authors.affiliation: Private Practice, Porto, Portugal.
authors.forename: Manuel
authors.initials: M
authors.lastname: Neves
mesh_terms: D000328:Adult; D000848:Anodontia; D001291:Attitude of Health Personnel; D001294:Attitude to Health; D003815:Dentists; D004954:Esthetics; D004955:Esthetics, Dental; D005260:Female; D006801:Humans; D007180:Incisor; D008297:Male; D012904:Smiling
keywords: Maxillary lateral incisor agenesis (MLIA); close space; esthetic perception; laypersons; open space; professional; smiling