Vertical Effects in Class II Patients Treated With Distalization

In the PG, all patients received a pendulum appliance as described by Angelieri et al. The Nance button was anchored to the first and second premolars with removable wires. The 0.032-inch TMA wires were activated 45 degrees to produce a force of 200-250g per side. On average, intraoral reactivation of the distalizing springs was performed twice during the procedure. When a super Class I molar relationship was obtained, pendulum was replaced by a Nance holding arch. The average treatment duration was 8 months followed by bracket conventional therapy.

The standardized orthodontic intervention was represented by the maxillary molar distalization protocol proposed by Align Technology: it was planned in order to obtain a sequential distalization on the upper arch, and the staging was set at 0.25 mm per aligner. During sequential distalization aligners are set up to distalize one tooth at a time. The attachments were engineered by Align Technology to achieve predictable tooth movements. Each couple of aligners was worn for 7 days.