Comparison of Two Different Mini-Implant Position in Maxillary Incisors Intrusion (Cone Beam Study)

Abstract

Aim: To compare, through cone-beam computed tomography (CBCT), the root resorption of two different mini-implant-assisted modalities in intruding the maxillary incisors. Subjects and Methods: The present study composed of 26 patients (males, females) aged between 12-18 years who had deep bite and need maxillary incisors intrusion. They were randomly selected and divided into two group: anterior miniimplant group (AMG) and posterior mini-implant group (PMG). In the AMG, approximately 40 g of force was applied per side with elastic chains and in the PMG, with beta-titanium wires with modification of three pieces intrusive arch. This study was conducted on cone beam computed tomography scans taken before intrusion and after 18 weeks of intrusion. Results: The incisors showed a significant reduction in length, this amount was greater in AMG than PMG. Conclusion: Posterior miniimplants assisted maxillary incisors intrusion show less root resorption than anterior mini-implant assisted maxillary incisor intrusion. INTRODUCTION Deep bites can affect a person’s esthetic appearance and smile. Anterior deep bites caused by overeruption of the maxillary incisors can be determined by using lateral cephalometric radiographs. If the lower lip covers more than 4 mm of the maxillary central incisors on a patient’s lateral Cephalometric radiographs, it is the result of maxillary incisor overeruption.(1) Orthodontic treatment often includes the correction of a deep overbite.(2, 3) depending on the diagnosis and treatment objectives, deep overbites can be corrected by intruding the maxillary or mandibular incisors, extruding the buccal segments, or a combination of these. In recent years, the integration of mini-implants into intrusion mechanics has been proposed as an alternative technique to conventional mechanics, which have side effects on anchorage segments such as