title: Microradiographic and histological evaluation of the bone-screw and bone-plate interface of orthodontic miniplates in patients.
abstract: OBJECTIVE
  To describe the tissue reactions at the bone-titanium interface of orthodontic miniplates in humans.
  
  
  METHODS
  Forty-two samples, consisting of tissue fragments attached or not to miniplates or their fixation screws, were collected from 24 orthodontic patients treated with miniplate anchorage, at the time of removal of their miniplates. The samples were embedded in methylmethacrylate and cut into undecalcified sections which were submitted to microradiographic analysis. The sections were also stained and examined under ordinary light.
  
  
  RESULTS
  Three types of reactions were observed both on the histological sections and on the microradiographs. 1. The majority of the stable miniplates were easy to remove (34/42). The tissue samples collected consisted mainly in mature lamellar bone with some medullary spaces containing blood vessels, 2. two screws were highly osseointegrated and required the surgeon to remove them by trephining (2/42). They were surrounded by bone tissue which extended to the miniplate. The histological features were similar to the previous group, though the bone-screw contact was higher, and 3. in six samples obtained after unstable miniplate removal during the treatment, we observed either some woven bone trabeculae or loose connective tissue, without any histological sign of inflammation.
  
  
  CONCLUSIONS
  For evident ethical reasons, our data were limited by the size of the tissue fragments and the limited number of patients and variety of clinical presentations. The healing reactions consisted mainly in mature lamellar bone tissue sparsely in contact with the screw or the miniplate, with signs of a moderate remodelling activity.
authors.affiliation: *Pole of Morphology, Institut de recherche expérimentale et clinique, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Simon
authors.initials: S
authors.lastname: Vandergugten
authors.affiliation: **Department of Orthodontics, School of Dentistry, Université de Genève, Geneva, Switzerland, macornel@hotmail.com.
authors.forename: Marie A
authors.initials: MA
authors.lastname: Cornelis
authors.affiliation: ***Department of Oral & Maxillofacial Surgery, Cliniques Universitaires St-Luc, Institut de recherche expérimentale et clinique, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Mahy
authors.affiliation: ****Pole of Morphology, Institut de recherche expérimentale et clinique, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Catherine
authors.initials: C
authors.lastname: Nyssen-Behets
mesh_terms: D000293:Adolescent; D000328:Adult; D000497:Alloys; D001860:Bone Plates; D016723:Bone Remodeling / Q000502:physiology; D001863:Bone Screws; D002648:Child; D015331:Cohort Studies; D003238:Connective Tissue / Q000033:anatomy & histology; D003722:Dental Alloys / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry; D005260:Female; D006801:Humans; D007568:Jaw / Q000033:anatomy & histology*; D008297:Male; D020366:Methylmethacrylate / Q000737:chemistry; D008852:Microradiography / Q000379:methods; D008875:Middle Aged; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D016348:Osseointegration / Q000502:physiology; D016613:Plastic Embedding; D011446:Prospective Studies; D014025:Titanium / Q000737:chemistry; D055815:Young Adult
chemical_list: D000497:Alloys; D003722:Dental Alloys; D003764:Dental Materials; C031462:titanium alloy (TiAl6V4); D020366:Methylmethacrylate; D014025:Titanium