The purpose of this study was to evaluate the influence of proximity between self-drilling miniscrews (SDMI) and dental roots on their stability degree. Forty SDMIs were placed between the maxillary first molar and second premolar roots for anterior en-masse retraction. Forty post-surgical radiographs were used to measure the septum width in the insertion site (SWI) and the smallest distance between miniscrew head and dental root (SDR). In this regard, the miniscrews were divided in two group categories: according to the septum width in the insertion site, groups G1W (SWI≤3mm) and G2W (SWI>3mm), and according to the miniscrew dental root proximity, groups G1P (SDR≤0mm) and G2P (SDR>0mm). The mobility degree (MD) was monthly quantified to determine miniscrew stability, and the success rate of these devices was calculated. Furthermore, the influence of the following variables on the stability degree was evaluated: the presence of attached gingiva, sensitivity degree during miniscrew load, plaque amount around miniscrew, insertion height, and total evaluation period. All the groups were compared regarding mobility degree and success rate using t test and Fisher exact test, respectively. The results showed no significant difference in mobility degree and success rate between groups G1W and G2W. Similar results were observed when G1P and G2P were compared. The total success rate found was 90% and no variable was associated with miniscrew failure. Nevertheless, results showed that greater patient sensitivity degree was associated to miniscrew mobility, with consequent failure short time after insertion.