Maps of relative (to initial 0 screw position) displacements in correspondence to the screw position equal to d 1 mm, e 2 mm.
Fig. 8 "Annunciazione", backward area C: maps of relative (to initial 0 mm screw position) displacements in correspondence to the screw position equal to a 3.75 mm, b 6.25 mm, c 8.75 mm, and d 10 mm.
Finding the relation between force direction and tooth displacement allows us to choose appropriate the mini screw position and power arm height for favorable and successful tooth movement.
Severe slips can be challenging to manage, as achieving a screw position centrally in the epiphysis with PIS may be technically difficult and subsequent remodelling may be insufficient.
At the end, screw position has to be confirmed on antero-posterior, inlet and outlet views [15, 16, 17, 18, 19].
This differs from the four-arm RPEs, whose screw position creates bending moment that tend to deform the screw body on the horizontal plane (Fig. 11).
In this study, we aimed to determine the effect of bone mineral density (BMD), cortical bone thickness (CBT), screw position, and screw design on the stability of miniscrews.
The special mechanical energy increases when the reverse kneading element is located at the screw position where the material viscosity is relatively high during extrusion.
As suspected by others, the small amount of secondary dislocation might be due to the relative distal, almost subchondral screw position of the distal 2.2-mm fine-threaded miniscrews [23].
