title: Bone damage associated with orthodontic placement of miniscrew implants in an animal model.
abstract: BACKGROUND
  The purposes of this study were to quantify bone damage associated with insertion of 2 types of miniscrew implants and to relate the amount of bone damage to monocortical plate thickness.
  
  
  METHODS
  Nondrilling (n = 28) and self-drilling (n = 28) miniscrew implants (6 × 1.6 mm, Dentaurum, Newtown, Pa), and pilot holes (n = 26) were placed bilaterally in the maxillae and the mandibles of 5 adult dogs immediately after death. Bone blocks were cut, bulk stained with 1% basic fuchsin, embedded in methyl methacrylate, sectioned, and mounted. Monocortical plate thickness was measured adjacent to the miniscrew implant insertion site. Damage amounts were quantified at distances of 0 to 0.5 mm (adjacent region) and 0.5 to 1 mm (distant region) from the bone-implant interface. Total fractional damaged area (%), fractional microcracked area (%), and fractional diffuse damaged area (%) were quantified by using standard histomorphometric methods.
  
  
  RESULTS
  The mean monocortical plate thickness of the specimens from the mandible (2.2 mm) was significantly (P <0.001) greater than that of the maxillary specimens (0.9 mm). In the mandible, the 3 damage parameters were greater with self-drilling miniscrew implants than with nondrilling miniscrew implants; however, there were no differences in the damage parameters in the maxilla.
  
  
  CONCLUSIONS
  Bone damage accumulation is related to the type of miniscrew implant and the thickness of the bone.
authors.affiliation: Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, Ohio, USA.
authors.forename: S Brooke
authors.initials: SB
authors.lastname: Shank
authors.forename: F Michael
authors.initials: FM
authors.lastname: Beck
authors.forename: Andrew M
authors.initials: AM
authors.lastname: D'Atri
authors.forename: Sarandeep S
authors.initials: SS
authors.lastname: Huja
mesh_terms: D000818:Animals; D004396:Coloring Agents; D015921:Dental Implants / Q000009:adverse effects*; D004285:Dogs; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008338:Mandibular Injuries / Q000209:etiology* / Q000473:pathology; D008437:Maxilla / Q000293:injuries* / Q000473:pathology; D020366:Methylmethacrylate; D008856:Microscopy, Fluorescence; D008867:Microtomy; D023421:Models, Animal; D052280:Orthodontic Anchorage Procedures / Q000009:adverse effects / Q000295:instrumentation*; D016382:Orthodontic Appliance Design; D016613:Plastic Embedding; D012394:Rosaniline Dyes; D013499:Surface Properties
chemical_list: D004396:Coloring Agents; D015921:Dental Implants; D012394:Rosaniline Dyes; D020366:Methylmethacrylate; C025485:basic fuchsin