Vertical Effects in Class II Patients Treated With Distalization

Summary

Class II malocclusion presents a major and common challenge to orthodontists. Treatment of Class II malocclusion is one of the most investigated and controversial issues in contemporary orthodontics because of the extensive variability of treatment strategies addressing the morphological characteristics of this malocclusion. The therapeutic approaches include tooth extractions, orthopedic appliances and extraoral or intraoral distalizing appliances. Maxillary molar distalization is one of the most common strategies to correct Class II molar relationship and it is commonly indicated for patients with maxillary dentoalveolar protrusion or minor skeletal discrepancies. One of the most used devices is Pendulum appliance, introducted by Hilgers in 1992.

In the last decades, the orthodontic treatment with removable clear aligners has become an increasing common choice because of the growing number of adult patients who ask for aesthetic and comfortable alternatives to conventional fixed appliances.

In 1997, Align Technology (Santa Clara, Calif) adapted and incorporated modern technologies to introduce the clear aligner treatment (CAT). Only few investigations have focused on the predictability of orthodontic tooth movement with CAT. A systematic review by Rossini et al. pointed out that among the dental movements analyzed in 11 studies, the bodily distalization was the most predictable.

Clinicians can consider the use of aligners in treatment planning for adult patients requiring 2 to 3 mm of maxillary molar distalization.

However, a detailed analysis of the skeletal and dental changes that compared pendulum appliance and clear aligners in class II treatment is still lacking.

On the basis of these considerations, the aim of the present prospective study was to analyze the effects on vertical dentoskeletal changes following maxillary molar distalization with pendulum and full fixed appliances and clear aligners.

Conditions

• Malocclusion, Angle Class II

Interventions

DEVICE

Pendulum appliance

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.

DEVICE

clear aligners

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.

Sponsors & Collaborators

• University of Rome Tor Vergata

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2019-01-01

Primary Completion

2021-07-31

Completion

2021-12-31

Countries

• Italy

Study Locations