title: Immediate periodontal bone plate changes induced by rapid maxillary expansion in the early mixed dentition: CT findings.
abstract: OBJECTIVE
  This study aimed at evaluating buccal and lingual bone plate changes caused by rapid maxillary expansion (RME) in the mixed dentition by means of computed tomography (CT).
  
  
  METHODS
  The sample comprised spiral CT exams taken from 22 mixed dentition patients from 6 to 9 years of age (mean age of 8.1 years) presenting constricted maxillary arch treated with Haas-type expanders. Patients were submitted to spiral CT scan before expansion and after the screw activation period with a 30-day interval between T1 and T2. Multiplanar reconstruction was used to measure buccal and lingual bone plate thickness and buccal bone crest level of maxillary posterior deciduous and permanent teeth. Changes induced by expansion were evaluated using paired t test (p < 0.05).
  
  
  RESULTS
  Thickness of buccal and lingual bone plates of posterior teeth remained unchanged during the expansion period, except for deciduous second molars, which showed a slight reduction in bone thickness at the distal region of its buccal aspect. Buccal bone dehiscences were not observed in the supporting teeth after expansion.
  
  
  CONCLUSIONS
  RME performed in mixed dentition did not produce immediate undesirable effects on periodontal bone tissues.
authors.forename: Daniela Gamba
authors.initials: DG
authors.lastname: Garib
authors.forename: Maria Helena Ocké
authors.initials: MH
authors.lastname: Menezes
authors.forename: Omar Gabriel
authors.initials: OG
authors.lastname: Silva Filho
authors.forename: Patricia Bittencourt Dutra
authors.initials: PB
authors.lastname: Santos
mesh_terms: D000539:Alveolar Process / Q000000981:diagnostic imaging*; D001641:Bicuspid / Q000000981:diagnostic imaging; D002508:Cephalometry / Q000379:methods; D002648:Child; D003481:Cuspid / Q000000981:diagnostic imaging; D003724:Dental Arch / Q000000981:diagnostic imaging; D003818:Dentition, Mixed; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging; D008963:Molar / Q000000981:diagnostic imaging; D016382:Orthodontic Appliance Design; D010155:Palatal Expansion Technique / Q000295:instrumentation; D036542:Tomography, Spiral Computed / Q000379:methods*; D014083:Tooth Germ / Q000000981:diagnostic imaging; D014094:Tooth, Deciduous / Q000000981:diagnostic imaging
keywords: Palatal expansion technique; Periodontium; Spiral computed tomography