title: Prediction of the alveolar bone level after the extraction of maxillary anterior teeth with severe periodontitis.
abstract: OBJECTIVE
  After extraction, the alveolar bone tends to undergo atrophy in three-dimensions. The amount of alveolar bone loss in the horizontal dimension has been reported to be greater than the amount of bone loss in the vertical dimension, and is most pronounced in the buccal aspect. The aim of this study was to monitor the predictive alveolar bone level following the extraction of anterior teeth seriously involved with advanced chronic periodontitis.
  
  
  METHODS
  This study included 25 patients with advanced chronic periodontitis, whose maxillary anterior teeth had been extracted due to extensive attachment loss more than one year before the study. Periapical radiographs were analyzed to assess the vertical level of alveolar bone surrounding the edentulous area. An imaginary line connecting the mesial and the distal ends of the alveolar crest facing the adjacent tooth was arbitrarily created. Several representative coordinates were established in the horizontal direction, and the vertical distance from the imaginary line to the alveolar crest was measured at each coordinate for each patient using image analysis software. Regression functions predicting the vertical level of the alveolar bone in the maxillary anterior edentulous area were identified for each patient.
  
  
  RESULTS
  The regression functions demonstrated a tendency to converge to parabolic shapes. The predicted maximum distance between the imaginary line and the alveolar bone calculated using the regression function was 1.43±0.65 mm. No significant differences were found between the expected and actual maximum distances. Likewise, the predicted and actual maximum horizontal distances did not show any significant differences. The distance from the alveolar bone crest to the imaginary lines was not influenced by the mesio-distal spans of the edentulous area.
  
  
  CONCLUSIONS
  After extraction, the vertical level of the alveolar ridge increased to become closer to the reference line connecting the mesial and distal alveolar crests.
authors.affiliation: Department of Periodontology, Pusan National University School of Dentistry, Yangsan, Korea .
authors.forename: Chul Eui
authors.identifier: 0000-0002-3996-8911
authors.initials: CE
authors.lastname: Hong
authors.affiliation: Department of Periodontology, Pusan National University School of Dentistry, Yangsan, Korea.; Department of Periodontology, Pusan National University Dental Hospital, Dental Research Institute, Yangsan, Korea.
authors.forename: Ju-Youn
authors.identifier: 0000-0002-0772-033X
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Periodontology, Pusan National University School of Dentistry, Yangsan, Korea.; Department of Periodontology, Pusan National University Dental Hospital, Dental Research Institute, Yangsan, Korea.
authors.forename: Jeomil
authors.identifier: 0000-0002-7491-6711
authors.initials: J
authors.lastname: Choi
authors.affiliation: Department of Periodontology, Pusan National University School of Dentistry, Yangsan, Korea.; Department of Periodontology, Pusan National University Dental Hospital, Dental Research Institute, Yangsan, Korea.
authors.forename: Ji-Young
authors.identifier: 0000-0002-4050-5797
authors.initials: JY
authors.lastname: Joo
keywords: Alveolar bone loss; Periodontitis; Tooth extraction