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.Materials and 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.

Mechanical and histological evaluation of a titanium device for orthodontic anchorage, placed with or without cyanoacrylate adhesive

“…Other considerations for these devices include the use of biological adhesive, a greater device diameter, a surface treatment or the combined insertion of mini-implant and auxiliary accessories with indentations facing the cortical bone 3 12 , 22 The application of small amounts of the adhesive lateral to the device 23 should be evaluated for primary stability in patients with thin cortical bone.…”

Evaluation of miniscrew stability using an automatic embedding auxiliary skeletal anchorage device

“…In the present study, to evaluate the mechanical retention force of the miniscrews with and without the auxiliary device, the lateral displacement test was used. 12,22 Several studies have evaluated the stability of the implant by measuring insertion torque, removal torque, and pull-out strength. 5,25 However, measuring the insertion and removal torques cannot confirm the movement of the miniscrew during loading.…”

“…The mechanical retention force was evaluated by measuring the displacement of the miniscrew head. 12,22 The specimens were embedded into the plaster cube such that the long axis of the miniscrew was perpendicular to the bottom of the cube and the long axis of the femur was perpendicular to the side of the cube. Twelve hours after embedding the specimens into the cubes (Figure 3A), the displacement of the miniscrew head was measured after bidirectional loading using a compression test machine (TGE-5kN; Minebea, Nagano, Japan) set at a load of 5.0 kN and a compression velocity of 0.5 mm/min ( Figure 3B).…”

“…To date, several new designs of skeletal anchorage devices have been introduced to increase miniscrew stability, including the washer, 10,11 mini-implant ring, 12 and spiky miniplate. 13 However, the development of a clinically reliable skeletal anchorage device is still pending.…”

Evaluation of primary stability of innovated orthodontic miniscrew system (STS): An ex-vivo study

“…The present study represents an innovated design for skeletal anchorage devices without any intervention to the miniscrew designed by the manufacturer. Tozlu et al ( 28 ), has created an apparatus (a miniscrew ring) which was placed at the neck of the screw. The mentioned study claimed that this ring is able to increase stability due to increasing surface contact of bone with miniscrew.…”