title: Bone condition of the maxillary zygomatic process prior to orthodontic anchorage plate fixation.
abstract: OBJECTIVE
  The clinical success of orthodontic miniplates depends on the stability of the miniscrews used for fixation. For good stability, it is essential that the application site provides enough bone of good quality. This study was performed to analyze the amount of bone available for orthodontic miniplates in the zygomatic process of the maxilla.
  
  
  METHODS
  We examined 51 dental CT scans (Somatom Plus 4; Siemens, Erlangen, Germany) obtained from 51 fully dentate adult patients (mean age 24.0 ± 8.1 years; 27 male and 24 female) prior to third molar surgery. The amount of bone in the zygomatic process region at the level of the first molar root tips and at several other cranial levels as far as 15 mm from the root tips was measured
  
  
  RESULTS
  Bone thickness at the root tip level averaged 4.1 ± 1.0 mm; the lowest value measured at this level in any of the patients was 2.7 mm. Bone thickness averaged 8.3 ± 1.0 mm at 15 mm cranial to the root tips; 6.9 mm was the lowest value.
  
  
  CONCLUSIONS
  The zygomatic process appears to provide sufficient bone to accommodate screws for miniplate fixation. While some patients may possess a borderline amount of bone at more caudal levels, lack of volume is not a problem near the zygomatic bone.
authors.affiliation: Department of Orthodontics, Dentofacial Orthopedics and Pedodontics, Charité - University Medicine Berlin, Assmannshauser Str. 4-6, 14197, Berlin, Germany, thomas-michael.praeger@charite.de.
authors.forename: T M
authors.initials: TM
authors.lastname: Präger
authors.forename: H G
authors.initials: HG
authors.lastname: Brochhagen
authors.forename: R
authors.initials: R
authors.lastname: Mischkowski
authors.forename: P G
authors.initials: PG
authors.lastname: Jost-Brinkmann
authors.forename: R
authors.initials: R
authors.lastname: Müller-Hartwich
mesh_terms: D000328:Adult; D000540:Alveolar Ridge Augmentation / Q000295:instrumentation* / Q000379:methods; D001860:Bone Plates; D001863:Bone Screws; D005260:Female; D006801:Humans; D008297:Male; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation* / Q000379:methods; D011861:Radiography, Dental; D055815:Young Adult; D015050:Zygoma / Q000000981:diagnostic imaging / Q000601:surgery*