title: Effect of 3 vertical facial patterns on alveolar bone quality at selected miniscrew implant sites.
abstract: OBJECTIVE
  To evaluate dental alveolar bone quality among young healthy Chinese adults having 3 different vertical patterns.
  
  
  METHODS
  Three-dimensional cone-beam computed tomography images of 101 subjects (15 low-angle, 48 average-angle, and 38 high-angle) were reconstructed. Facial alveolar cortical bone thicknesses and cortical and cancellous bone densities at 4 selected miniscrew implant sites in both arches, together with cancellous bone densities of third cervical vertebrae, were measured. Bone qualities were compared among the 3 vertical pattern groups.
  
  
  RESULTS
  The cortical bone thicknesses at mandibular 5-6 and 6-7 and the cortical and cancellous bone densities at maxillary and mandibular 5-6 and 6-7 were generally greater in the low-angle than in the other 2 groups. There was no similar consistent vertical pattern apparent for bone quality at the 1-1 and 1-2 sites. No significant differences in bone densities for third cervical vertebrae were found among the 3 groups.
  
  
  CONCLUSIONS
  Careful selection of suitable implantation sites and sizes of the miniscrews used should be made to reduce the possible occurrence of implant loosening in patients with average-angle and high-angle vertical facial patterns in particular.
authors.affiliation: *MD Student, Institute of Stomatology, Nanjing Medical University, Nanjing, People's Republic of China; Resident, Department of Orthodontics, Zhenjiang Stomatological Hospital, Zhenjiang, People's Republic of China. †MD Student, Institute of Stomatology, Nanjing Medical University, Nanjing, People's Republic of China ‡Visiting Research Fellow, School of Dentistry, Faculty of Health Sciences, The University of Adelaide, Adelaide, Australia. §Associate Professor, Institute of Stomatology, Nanjing Medical University, Nanjing, People's Republic of China. ‖Professor, Institute of Stomatology, Nanjing Medical University, Nanjing, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Roger J
authors.initials: RJ
authors.lastname: Smales
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Ni
authors.forename: Junqing
authors.initials: J
authors.lastname: Ma
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000539:Alveolar Process / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D015519:Bone Density; D001863:Bone Screws; D054893:Cone-Beam Computed Tomography; D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000379:methods*; D005145:Face / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008437:Maxilla / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D055815:Young Adult