Nonsurgical clear aligner treatment of an adult right-sided Class III subdivision malocclusion using miniscrew-assisted mandibular distalization: A case report.

Abstract

Adult asymmetric Class III malocclusions can be challenging to camouflage when crowding, anterior crossbite, and dental midline discrepancies must be corrected without worsening an acceptable soft-tissue profile. This case report describes a 40-year-old woman with mild skeletal Class III malocclusion mainly due to maxillary retrusion, a normodivergent pattern, a right-sided Class III subdivision associated with leftward mandibular deviation, mild crowding in both arches, an edge-to-edge incisor relationship, and noncoincident dental midlines. After extraction of all third molars, treatment was performed with Invisalign Comprehensive aligners, staged interproximal enamel reduction, programmed maxillary incisor extrusion, and asymmetric mandibular distalization of up to 2.0mm on the right and 1.3mm on the left. Two posterior mandibular miniscrews were connected to composite buttons on the mandibular canines to reinforce distal traction, and a right-sided Class III elastic was added during refinement. A refinement-related posterior open bite was managed with posterior aligner cutback and vertical settling elastics. Active treatment lasted 21 months. Bilateral Class I canine and molar relationships, coincident dental midlines, positive overjet and overbite, correction of the anterior crossbite, and improved maxillary incisor display were achieved. Cephalometric changes were predominantly dentoalveolar, with maintenance of the skeletal pattern, mandibular incisor retraction, and lower-lip retrusion. Miniscrew anchorage was essential in combination with aligners, interproximal reduction, attachments, and elastics. The occlusion and periodontal condition remained stable at the 1-year follow-up.