title: Implants for orthodontic anchorage: success rates and reasons of failures.
abstract: BACKGROUND
  The aims of this study were to analyze the success rate of mini-implants and miniscrews and to report the reasons behind them.
  
  
  METHODS
  An electronic literature search from PubMed databases and a hand search in implant- and orthodontic-related journals were performed until December 31, 2011. Human clinical studies in English that reported temporary anchorage devices used for orthodontic purpose with at least 6 months follow-up were included. In addition, the minimal number of implants had to be at least 10. Implants placed in maxilla, mandible, and hard palate were included.
  
  
  RESULTS
  The initial search resulted in 847 articles, of which 46 were further evaluated. Finally, 29 studies were qualified and classified into 2 groups: implants placed in maxilla and mandible (group 1) and implants placed in hard palate (group 2). A meta-analysis performed for groups 1 and 2 showed 87.8% and 93.8% survival rate, respectively. In addition, the most common cause for implants failure was surgery-related factors.
  
  
  CONCLUSIONS
  Mini-implant survival rate is location dependent, with those placed in the palate showing higher success rates. In addition, failures most commonly occur because of surgery-related factors.
authors.affiliation: *Resident, Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI. †Visiting Scholar, Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI. ‡Adjunct Clinical Assistant Professor, Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI. §Research Fellow, Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI. ‖Professor and Director, Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Rodriguez
authors.forename: Fernando
authors.initials: F
authors.lastname: Suarez
authors.forename: Hsun-Liang
authors.initials: HL
authors.lastname: Chan
authors.forename: Miguel
authors.initials: M
authors.lastname: Padial-Molina
authors.forename: Hom-Lay
authors.initials: HL
authors.lastname: Wang
mesh_terms: D001863:Bone Screws / Q000009:adverse effects; D003757:Dental Implantation / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D019232:Dental Restoration Failure / Q000706:statistics & numerical data*; D006801:Humans; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D052280:Orthodontic Anchorage Procedures / Q000009:adverse effects / Q000379:methods*; D021362:Palate, Hard / Q000601:surgery; D016896:Treatment Outcome