title: Effects of a newly designed apparatus on orthodontic skeletal anchorage.
abstract: OBJECTIVE
  An appliance was designed to increase the cortical bone surface contact area of miniscrew implants (MSIs). The purpose of this in vitro study was to evaluate the effects of this appliance on the anchorage force resistance and the stability of orthodontic MSIs.
  
  
  METHODS
  A total of 48 MSIs were placed into bone specimens prepared from the ilium of bovines. Half were placed with the newly designed apparatus and half were placed conventionally. All the specimens were subjected to tangential force loading perpendicular to the MSI with lateral displacement of 0.6 mm, using an Instron Universal Testing machine. The maximum removal torque of each tested specimen was also recorded. Both study and control groups were divided into two subgroups based on whether they had thin and thick cortical bone.
  
  
  RESULTS
  The test group had statistically higher force anchorage resistance and maximum insertion torque values than the control group (P < 0.001). The results were found to be more significant in cases in which the cortical bone was thin (P < 0.001).
  
  
  CONCLUSIONS
  Within the limits of this in vitro study, the present findings suggest that the newly designed apparatus might have a favorable effect on MSI stability in patients presenting with thin cortical bone. Clinical studies are necessary to confirm the results that were observed in vitro.
authors: Department of Orthodontics, Faculty of Dentistry, Yeditepe University, Istanbul, Turkiye.
authors: Murat
authors: M
authors: Tozlu
authors: Department of Orthodontics, Faculty of Dentistry, Yeditepe University, Istanbul, Turkiye.
authors: Didem
authors: D
authors: Nalbantgil
authors: Department of Orthodontics, Faculty of Dentistry, Yeditepe University, Istanbul, Turkiye.
authors: Fulya
authors: F
authors: Ozdemir
keywords: Anchorage; loading test; mini implant ring; mini-implant; stability