title: Alveolar Bone Architecture: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  There is a need for studying bone characteristics systematically for a better understanding of planning (i.e., timing of placement and loading) and outcomes of implant therapy. Therefore, the aim of the present review is to evaluate alveolar bone microarchitecture and its modifiers.
  
  
  METHODS
  Two independent reviewers conducted electronic and manual literature searches in several databases, including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Oral Health Group Trials Register, for articles published up to February 2015 reporting alveolar bone microstructure. The random-effect model was applied to calculate the weighted mean (WM) of total bone volume (TBV), which has a range from 0 to 1. TBV was stratified by anatomic locations, atrophic status, and types of specimens. Correlations between TBV and other bone-related parameters were also analyzed.
  
  
  RESULTS
  A total of 800 articles were initially identified. After abstract/full-text review, 24 articles were included in the systematic review, of which 23 were also included in the quantitative analysis. The WM TBV was 0.365 (95% confidence interval = 0.278 to 0.452), higher in the maxillary/mandibular anterior sites than the maxillary/mandibular posterior sites. However, great variations existed within each anatomic location. Additionally, WM TBV was lower in atrophic sites than non-atrophic sites. TBV was correlated negatively with trabecular spacing (R(2) = 0.11).
  
  
  CONCLUSIONS
  The present systematic review suggests that the TBV might not be different between the defined anatomic locations. However, the atrophy status might influence TBV.
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.
authors.forename: Alberto
authors.initials: A
authors.lastname: Monje
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.
authors.forename: Hsun-Liang
authors.initials: HL
authors.lastname: Chan
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.|Oral Surgery and Implant Dentistry Department, School of Dentistry, University of Granada, Granada, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Galindo-Moreno
authors.affiliation: Department of Oral Surgery and Implantology, International University of Catalonia, Catalonia, Spain.
authors.forename: Basel
authors.initials: B
authors.lastname: Elnayef
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.
authors.forename: Fernando
authors.initials: F
authors.lastname: Suarez-Lopez del Amo
authors.affiliation: Department of Oral Implantology, Ninth People's Hospital Affiliated with Shanghai Jiao Tong University, School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.
authors.forename: Hom-Lay
authors.initials: HL
authors.lastname: Wang
mesh_terms: D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D006801:Humans; D008334:Mandible; D008437:Maxilla; D016032:Randomized Controlled Trials as Topic
chemical_list: D015921:Dental Implants
keywords: Alveolar bone grafting; bone and bones; dental implantation; dental implants; endosseous; evidence-based dentistry