Simulation of miniscrew-root distance available for molar distalization depending on the miniscrew insertion angle and vertical facial type.

Miniscrew-root distance increased significantly with the increased insertion angle, and the amount of increase was affected by the miniscrew placement site and vertical facial type. To ensure adequate distalization of the posterior segment, the miniscrew should be inserted at an angle in the interradicular area between the second premolar and first molar.