title: [Stability of upper molars with the application of implant anchorage].
abstract: OBJECTIVE
  To investigate the stability of upper molars with the application of micro-screw implant anchorage during orthodontic treatment.
  
  
  METHODS
  Fifteen adult patients with severe maxillary protrusion were included. Upper first premolars were extracted and upper posterior anchorage was reinforced with micro-screw implant in all patients. The average treatment period to close the extraction space was 10.5 months. Cephalometric and cast analysis were carried out.
  
  
  RESULTS
  During the treatment, the micro-screw implants kept stable in sagittal plane; neither the mesial-distal movement nor the rotation or tipping of the upper molars during the treatment was of statistic significance (P > 0.05); the edge of upper incisors was retracted by 6.99 mm on average, and no significant vertical change was observed (P > 0.05).
  
  
  CONCLUSIONS
  Micro-screw implant could provide good anchorage control in the orthodontic treatment.
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Sheng-ji
authors.initials: SJ
authors.lastname: Zhu
authors.forename: Yan-heng
authors.initials: YH
authors.lastname: Zhou
authors.forename: Min-kui
authors.initials: MK
authors.lastname: Fu
mesh_terms: D000293:Adolescent; D000328:Adult; D001863:Bone Screws; D015921:Dental Implants; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy; D008963:Molar / Q000502:physiology*; D052280:Orthodontic Anchorage Procedures; D009971:Orthodontics, Corrective / Q000379:methods; D011378:Prognathism / Q000628:therapy*; D055815:Young Adult
chemical_list: D015921:Dental Implants