The aim of this study is to present a new appliance called stability leg designed as an additional anchorage providing device for increasing primary stability of orthodontic miniscrew. For this purpose, two finite element models (FEMs) with two different cortical layer thicknesses of 1mm and 2mm are considered. In order to achieve the stability analysis, these two main models, namely, Model I and Model II, are divided into subgroups according to stability leg lengths. Two types of forces are considered. (1) First force is a constant force of 1N which is applied to all two models. (2) Second force is defined in the range of 1-4N. Each of 1, 2.5, and 4N of the second force is applied with a position angle ranging from 34 degrees to 44 degrees. Results show that stability of a miniscrew with 5mm leg increases primary stability of the miniscrew.