Preformed intrusion bulbs on clear aligners facilitate active vertical control in a hyperdivergent skeletal Class II case with extraction: A case report with 4-year follow-up

Active vertical control is critical in the treatment of hyperdivergent skeletal Class II malocclusion. The mechanics have been well shown as successful in the fixed appliance system with temporary anchorage devices (TADs); however, there are few relevant case reports in clear aligner therapy (CAT). The present case report describes the treatment of a severe hyperdivergent skeletal Class II case using CAT with the extraction of four premolars. Active vertical control was performed with TADs, which was facilitated by intrusion bulbs (IBs), that is, digitally designed and preformed vacuum bulbs on clear aligners for wearing intrusive elastics. The challenging camouflage case was finished with an improved profile and occlusion; specifically, the upper central incisors were intruded for 3 mm and the first molars for 1.8 mm, with counter-clockwise rotation of the mandible for 2.2° and a decrease of the ∠ANB for 2.6°. After a 4-year follow-up (the latter 2 years without retainers), the treatment results remain stable on the whole. According to the case report, camouflage treatment of hyperdivergent skeletal Class II case can be successfully achieved with active vertical control using TADs, facilitated by preformed IBs on the clear aligners.