Nonsurgical correction of a Class III malocclusion in an adult by miniscrew-assisted mandibular dentition distalization

摘要

This article reports the successful use of miniscrews in the mandible to treat a 20-year-old Mongolian woman with a chief complaint of anterior crossbite. The patient had a skeletal Class III malocclusion with a mildly protrusive mandible, an anterior crossbite, and a deviated midline. In light of the advantages for reconstruction of the occlusal plane and distal en-masse movement of the mandibular arch, we used a multiloop edgewise archwire in the initial stage. However, the maxillary incisors were in excessive labioversion accompanied by little retraction of the mandibular incisors; these results were obviously not satisfying after 4 months of multiloop edgewise archwire treatment. Two miniscrews were subsequently implanted vertically in the external oblique ridge areas of the bilateral mandibular ramus as skeletal anchorage for en-masse distalization of the mandibular dentition. During treatment, the mandibular anterior teeth were retracted about 4.0 mm without negative lingual inclinations. The movement of the mandibular first molar was almost bodily translation. The maxillary incisors maintained good inclinations by rotating their brackets 180° along with the outstanding performance of the beta-titanium wire. The patient received a harmonious facial balance, an attractive smile, and ideal occlusal relationships. The outcome was stable after 1 year of retention. Our results suggest that the application of miniscrews in the posterior area of the mandible is an effective approach for Class III camouflage treatment. This technique requires minimal compliance and is particularly useful for correcting Class III patients with mild mandibular protrusion and minor crowding.