title: Factors affecting smile esthetics in adults with different types of anterior overjet malocclusion.
abstract: OBJECTIVE
  This study aimed to quantitatively assess the relationship of smile esthetic variables with various types of malocclusion, and identify the cephalometric factors affecting smile measurements.
  
  
  METHODS
  This retrospective study included 106 patients who were treated with retention at the orthodontic department of Taipei Medical University Hospital. Hard-tissue variables were measured using lateral cephalographic tracings, and nine smile esthetic variables were measured using facial photographs. The patients were divided into three groups according to their overjet (< 0, 0-4, and > 4 mm). An analysis of variance was conducted to compare the pretreatment cephalometric variables and smile esthetic variables among the three groups. Multiple linear regression analysis was performed to identify the cephalometric factors affecting the smile measurements in each group.
  
  
  RESULTS
  Except the upper midline and buccal corridor ratio, all of the smile measurements differed significantly among the three groups before orthodontic treatment. Some of the smile characteristics were correlated with the cephalometric measurements in different types of malocclusion. The overjet was the major factor influencing the smile pattern in all three types of malocclusion.
  
  
  CONCLUSIONS
  Smile characteristics differ between different types of malocclusion; the smile may be influenced by skeletal pattern, dental procumbency, or facial type. These findings indicate that establishment of an optimal horizontal anterior teeth relationship is the key to improving the smile characteristics in different types of malocclusion.
authors.affiliation: School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.; Division of Orthodontics, Department of Dentistry, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Hsin-Chung
authors.initials: HC
authors.lastname: Cheng
authors.affiliation: School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.; Division of Orthodontics, Department of Dentistry, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Pei-Chin
authors.initials: PC
authors.lastname: Cheng
keywords: Esthetics; Malocclusion; Smile; Soft tissue