Treatment of Class III Malocclusions Using Miniplate and Mini-Implant Anchorage

Abstract

Orthodontic miniplates and mini-implants have become essential tools for anchorage management. This article presents the treatment of growing Class III patients with the use of the facemask in conjunction with the mini-plate (FM/MP), and also the treatment of postadolescent Class III patients camouflaged by the use of mini-implants as skeletal anchorage. For FM/MP therapy, an orthopedic force of more than 500 g per side with a vector of 30째 downward and forward from the occlusal plane was applied 12-14 hours per day after placement of the curvilinear type surgical miniplates in the zygomatic buttress areas of the maxilla. After 16 months of maxillary protraction, significant forward displacement of the maxilla (point A) was found. Side effects of maxillary protraction, such as labial tipping of the upper incisors, extrusion of the upper molars, clockwise rotations of the mandibular plane, and bite opening, which are usually observed using tooth-borne anchorage, were minimized. Therefore, FM/MP can be an effective alternative treatment modality for maxillary hypoplasia with minimal unwanted side effects. Class III patients in the postadolescent period can be camouflaged with fixed appliance by the use of mini-implants as skeletal anchorage. The authors prefer to install the mini-implants in the buccal attached gingiva between the upper second premolar and the first molar. Class I intraarch elastics can be used to decompensate the already labially inclined upper incisors. Class III interarch elastics can be used for distal en masse movement of the lower dentition. Vertical elastics can be used to correct an open bite problem if present. Extrusion or intrusion of the lower molars can be controlled with strategic positioning of the mini-implants in the lower arch. With an understanding of biomechanics, the careful use of miniplates and mini-implants can expand the boundaries and scope of conventional fixed appliance therapy. (C) 2011 Elsevier Inc.