Treatment of VME using extra-alveolar TADs: Quantification of treatment effects

Abstract

Introduction: Temporary anchorage devices (TADs) have been shown to be effective in the treatment of VME and/or bimaxillary protrusion but literature focus has been on maxillary miniscrews and not on the efficacy of mandibular TADs. In the present study, orthodontic extraction therapy was combined with maxillary extra-alveolar TADs in the treatment of all VME patient-subjects. The purpose was to investigate how various combinations of mandibular anterior and/or posterior extra-alveolar implants affected VME correction. The null hypothesis was no difference in treatment effects relative to mandibular TAD placement strategy. Methods: Sixty-nine VME, bimaxillary protrusive, smile patients were grouped according to mandibular extra-alveolar TAD placement configuration; soft and hard tissue treatment effects were evaluated using a cephalometric analysis comprised of 24 measurements. Results: (1) Posterior miniscrew anchorage provided favorable horizontal anchorage control with maximal, non-compliance retraction of upper anterior teeth. (2) Soft tissue profile changes secondary to maximum anterior retraction resulted in the greatest amount of lip retraction reported in the literature to date. (3) Combined use of posterior and anterior miniscrews provides favorable vertical control with counterclockwise mandibular rotation and posterior facial height reduction for hyperdivergent patients. (4) The anchorage configuration based upon combining posterior and anterior extra-alveolar TADs is effective in the treatment of VME patients with bimaxillary protrusion and gummy smile.