title: Evaluation of alveolar bone loss following rapid maxillary expansion using cone-beam computed tomography.
abstract: OBJECTIVE
  To evaluate the changes in cortical bone thickness, alveolar bone height, and the incidence of dehiscence and fenestration in the surrounding alveolar bone of posterior teeth after rapid maxillary expansion (RME) treatment using cone-beam computed tomography (CBCT).
  
  
  METHODS
  The CBCT records of 20 subjects (9 boys, mean age: 13.97 ± 1.17 years; 11 girls, mean age: 13.53 ± 2.12 year) that underwent RME were selected from the archives. CBCT scans had been taken before (T1) and after (T2) the RME. Moreover, 10 of the subjects had 6-month retention (T3) records. We used the CBCT data to evaluate the buccal and palatal aspects of the canines, first and second premolars, and the first molars at 3 vertical levels. The cortical bone thickness and alveolar bone height at T1 and T2 were evaluated with the paired-samples t-test or the Wilcoxon signed-rank test. Repeated measure ANOVA or the Friedman test was used to evaluate the statistical significance at T1, T2, and T3. Statistical significance was set at p < 0.05.
  
  
  RESULTS
  The buccal cortical bone thickness decreased gradually from baseline to the end of the retention period. After expansion, the buccal alveolar bone height was reduced significantly; however, this change was not statistically significant after the 6-month retention period. During the course of the treatment, the incidence of dehiscence and fenestration increased and decreased, respectively.
  
  
  CONCLUSIONS
  RME may have detrimental effects on the supporting alveolar bone, since the thickness and height of the buccal alveolar bone decreased during the retention period.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Izmir Katip Celebi University, Izmir, Turkey.
authors.forename: Asli
authors.initials: A
authors.lastname: Baysal
authors.forename: Tancan
authors.initials: T
authors.lastname: Uysal
authors.forename: Ilknur
authors.initials: I
authors.lastname: Veli
authors.forename: Torun
authors.initials: T
authors.lastname: Ozer
authors.forename: Irfan
authors.initials: I
authors.lastname: Karadede
authors.forename: Seyit
authors.initials: S
authors.lastname: Hekimoglu
keywords: Cone-beam computed tomography; Periodontium; Rapid maxillary expansion