title: Alterations of papilla dimensions after orthodontic closure of the maxillary midline diastema: a retrospective longitudinal study.
abstract: OBJECTIVE
  The aim of this study was to evaluate alterations of papilla dimensions after orthodontic closure of the diastema between maxillary central incisors.
  
  
  METHODS
  Sixty patients who had a visible diastema between maxillary central incisors that had been closed by orthodontic approximation were selected for this study. Various papilla dimensions were assessed on clinical photographs and study models before the orthodontic treatment and at the follow-up examination after closure of the diastema. Influences of the variables assessed before orthodontic treatment on the alterations of papilla height (PH) and papilla base thickness (PBT) were evaluated by univariate regression analysis. To analyze potential influences of the 3-dimensional papilla dimensions before orthodontic treatment on the alterations of PH and PBT, a multiple regression model was formulated including the 3-dimensional papilla dimensions as predictor variables.
  
  
  RESULTS
  On average, PH decreased by 0.80 mm and PBT increased after orthodontic closure of the diastema (P<0.01). Univariate regression analysis revealed that the PH (P=0.002) and PBT (P=0.047) before orthodontic treatment influenced the alteration of PH. With respect to the alteration of PBT, the diastema width (P=0.045) and PBT (P=0.000) were found to be influential factors. PBT before the orthodontic treatment significantly influenced the alteration of PBT in the multiple regression model.
  
  
  CONCLUSIONS
  PH decreased but PBT increased after orthodontic closure of the diastema. The papilla dimensions before orthodontic treatment influenced the alterations of PH and PBT after closure of the diastema. The PBT increased more when the diastema width before the orthodontic treatment was larger.
authors.affiliation: Department of Periodontology, Chonbuk National University School of Dentistry and Institute of Oral Bioscience, Jeonju, Korea .
authors.forename: Jin-Seok
authors.identifier: 0000-0002-7039-715X
authors.initials: JS
authors.lastname: Jeong
authors.affiliation: Department of Orthodontics, Chonbuk National University School of Dentistry and Institute of Oral Bioscience, Jeonju, Korea.; Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Korea.
authors.forename: Seung-Youp
authors.identifier: 0000-0002-7448-4082
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Periodontology, Chonbuk National University School of Dentistry and Institute of Oral Bioscience, Jeonju, Korea.; Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Korea.
authors.forename: Moontaek
authors.identifier: 0000-0002-0328-6572
authors.initials: M
authors.lastname: Chang
keywords: Dental esthetics; Gingiva; Orthodontic space closure