title: Cone-beam computed tomography evaluation of periodontal and bone support loss in extraction cases.
abstract: BACKGROUND
  The aim of this study was to evaluate, in particular, whether bone resorption occurred at the extraction sites of a group of patients under orthodontic treatment, and, in general, whether extraction treatment predisposes patients to a greater degree of root resorption.
  
  
  METHODS
  The study group comprised 12 class II division 1 malocclusion patients who underwent orthodontic treatment and extraction, and the control group comprised 10 class II division 1 patients who underwent orthodontic treatment without extraction. In both groups, treatments were carried out by the same operator using the same techniques. Cone-beam computed tomography performed before (T1) and after (T2) treatment was used to determine and compare the root length, the distance from the cementoenamel junction to the base of the defect and to the bone peak, the width of the defect and the buccolingual bone thickness.
  
  
  RESULTS
  Root length was reduced following treatment in both groups, although to a statistically significantly greater extent in the study group. The buccolingual bone thickness was reduced after treatment in both groups, with no differences found between the study and control groups. The bone loss at the sites assessed was greater in the patients after extraction treatment, with a statistically significant difference revealed between the two groups. The site that showed the greatest variation in both groups was distal to the upper canines.
  
  
  CONCLUSIONS
  In the present study, extractive orthodontic treatment appeared to predispose patients to a greater degree of root resorption. Indeed, the bone at the extraction site showed greater resorption in the study group with respect to the control group, and the appearance of intraosseous defects was noted in the former.
authors: Postgraduate school of orthodontics, Ferrara University, Via Montebello 31, Ferrara 44100, Italy. lulombardo@tiscali.it.
authors: Luca
authors: L
authors: Lombardo
authors: Romina
authors: R
authors: Bragazzi
authors: Carlo
authors: C
authors: Perissinotto
authors: Davide
authors: D
authors: Mirabella
authors: Giuseppe
authors: G
authors: Siciliani
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging*; D000539:Alveolar Process / Q000000981:diagnostic imaging; D001641:Bicuspid / Q000000981:diagnostic imaging / Q000601:surgery; D002648:Child; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003481:Cuspid / Q000000981:diagnostic imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000000981:diagnostic imaging; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008334:Mandible / Q000000981:diagnostic imaging; D008437:Maxilla / Q000000981:diagnostic imaging; D008963:Molar / Q000000981:diagnostic imaging; D012391:Root Resorption / Q000000981:diagnostic imaging; D019237:Tooth Cervix / Q000000981:diagnostic imaging; D014081:Tooth Extraction; D014087:Tooth Movement Techniques / Q000379:methods; D014092:Tooth Root / Q000000981:diagnostic imaging; D020390:Tooth Socket / Q000000981:diagnostic imaging*