title: [A clinical study on the stability of miniscrew anchorage in orthodontics].
abstract: OBJECTIVE
  The aim of this retrospective study was to summarize the cases who used miniscrew anchorage and to evaluate the clinical factors influencing the stability of miniscrew.
  
  
  METHODS
  The sample comprised 13 patients with 32 miniscrews, in whom the design, occlusogingival position, alveolar position, loading opportunity, gingival condition were investigated to assess the factors related to stability. The data was analyzed by univariate analysis and multivariate analysis using SAS 10.0 software package.
  
  
  RESULTS
  The overall success rate was 90.6%. There was significant relationship between the patients' age and the stability of miniscrews (P=0.04). The success rate was 75% in adolescent patients, and 100% in adult patients. The osseointegration was affected by initial over-loading, but the long-term orthodontic loading (200g) was safe, if osseointegration was achieved. Perio-implant gingivitis, even the suppurative gingivitis (2 cases) didn't destroy the bone-implant interface. The success rate was independent on gender, occlusogingival position, jaw positioning, inserting times of the same miniscrew, and early loading.
  
  
  CONCLUSIONS
  The primary stability is the crucial factor for long-term stability of the miniscrews.
authors: Department of Stomatology, Shanghai Jiao Tong University School of Medicine. Shanghai,China. yanyongqing008@163.com
authors: Yong-Qing
authors: YQ
authors: Yan
authors: Yi-Ming
authors: YM
authors: Gao
mesh_terms: D000293:Adolescent; D000328:Adult; D001863:Bone Screws; D003729:Dental Care; D006801:Humans; D052280:Orthodontic Anchorage Procedures; D016382:Orthodontic Appliance Design; D009970:Orthodontics; D016348:Osseointegration; D012189:Retrospective Studies