Excessive overjet, steep mandibular plane, and posterior buccal crossbite treated with aligners, infrazygomatic crest bone screws, and Class II elastics

Abstract

A 23-year-old male with dysfunctional incisors due to a large overjet preferred clear aligner therapy. Facial profile was convex with a skeletal Class II relationship (ANB, 8.4°). Overjet of 8.0 mm was associated with a hyperdivergent facial pattern and recessive chin. The UL7 was in buccal scissors bite, which contributed to a 2.0 mm functional shift to the right. Buccal relationships were Class I molar and Class II canines bilaterally. Other dental and facial structures were within normal limits. Aligners alone corrected the buccal scissors bite in 6 months and provided intrusive force in maxillary and mandibular buccal segments. Infrazygomatic crest bone screws served as anchorage for intra-arch elastics to retract the maxillary anterior segment. Class II intermaxillary elastics were added for the last stages of aligner treatment to help retract the upper incisors. After 12 months of treatment, the 8.0 mm overjet was resolved. Alignment with the initial set of aligners was completed in 15 months. A 5-month refinement phase with a second set of aligners was initiated to finish the occlusion. Total treatment time was 20 months. Overall, a malocclusion with a Discrepancy Index of 41 was treated to a Cast-Radiograph Evaluation score of 16 and a Pink and White esthetic score of 4.