title: [Histological study of miniscrew implanted in lower mandibles of juvenile and adult Beagle dogs].
abstract: OBJECTIVE
  To examine the histological discrepancies between juvenile and adult Beagle dogs at different concrescence times after miniscrew implants.
  
  
  METHODS
  Miniscrew implants were performed in six juvenile Beagle dogs and six adult Beagle dogs. The space between the fourth premolar root and first molar root, and the spaces in distal and mesial of M1 root were picked up for the implants of the 48 miniscrews. The lower jaw specimens including the miniscrews were harvested 3 and 12 weeks after the implants for the histological examinations and bone implant contact (BIC) calculations.
  
  
  RESULTS
  There was no miniscrew falling off or becoming loose. The miniscrews had favorable biological consistencies with the tissues around them. The osteoblasts and osteoclasts showed active functions in the peri-bones of the minisrews. The BIC became higher when the healing time was prolonged. The juvenile Beagle dogs had lower BIC than the adults 3 weeks after the implants. But the BIC of the juvenile dogs surpassed the adults 12 weeks after the implants.
  
  
  CONCLUSIONS
  The osseointegration of the miniscrews is hindered by the poorer bone quality of the juvenile Beagle dogs. But the early osseointegration deficiency can be made up by the rapid development and growth of the bones of the juvenile dogs.
authors.affiliation: Department of Orthodontics, West China Stomatology Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: Ying
authors.initials: Y
authors.lastname: Jia
authors.forename: Jun-Mei
authors.initials: JM
authors.lastname: Zhang
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Pu
authors.initials: P
authors.lastname: Yang
authors.forename: Tian
authors.initials: T
authors.lastname: Tang
authors.forename: Xiu-Ping
authors.initials: XP
authors.lastname: Wu
authors.forename: Lei-Lei
authors.initials: LL
authors.lastname: Zheng
authors.forename: Zhi-He
authors.initials: ZH
authors.lastname: Zhao
mesh_terms: D000367:Age Factors; D000539:Alveolar Process / Q000473:pathology; D000818:Animals; D001863:Bone Screws; D003758:Dental Implantation, Endosseous / Q000379:methods; D004285:Dogs; D020007:Implants, Experimental; D008334:Mandible / Q000473:pathology*; D008904:Miniaturization; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D016348:Osseointegration / Q000502:physiology*