3D Comparison of Anterior Teeth Retraction and Anchorage Control Between En-masse and Two-step Mechanics

Rio de Janeiro State University

Status: Unknown

Conditions: Bimaxillary Protrusion; Malocclusion, Angle Class I; Orthodontic Space Closure

Treatments: Procedure: En masse anterior teeth retraction; Procedure: Two-Step Retraction

Study type: Interventional

Funder types: Other

Identifiers

NCT03903575

04186818.2.0000.5259

Details and patient eligibility

About

The aim of this study is to compare en masse (EM) and two-step anterior teeth retraction (TSR) evaluated by means of three-dimensional images superimposition. Thirty-two adult patients with bimaxillary protrusion planed for treatment with four first premolar extractions will be enrolled. All patients will be randomly allocated in a 1:1 ratio to either EM (n=16) group or the TSR (n=16) group. Cone bean computed tomography will be taken before and after anterior retraction. A blind observer will construct separate 3D models for maxillary and mandibular surfaces using the anterior cranial fossa to register models of before and after space closing. Quantitative assessment of posterior anchorage loss and amount of anterior teeth retraction are the main outcomes. The secondary outcomes are the inclination of the molars, canines and incisors.

Enrollment: 32 estimated patients

Sex: All

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Angle Class I malocclusion;
• Bimaxillary protrusion;
• Convex profile;
• All natural teeth present in the mouth;
• Absence of crowding or with negative discrepancy up to 4mm;
• Absence of vertical and transverse occlusal problems;
• Good oral health;
• Good general health.

Exclusion criteria

• Lack of time to attend consultations;
• Patients with severe systemic and psychological illness;
• Patients with parafunction (bruxism), reflux or eating disorders;
• Presence of periodontal disease;

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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32 participants in 2 patient groups

En Masse Retraction

Experimental group

Description:

Group treated by retracting the six anterior teeth simultaneously.

Treatment:

Procedure: En masse anterior teeth retraction

Two-Step Retraction

Active Comparator group

Description:

Group treated by retracting the canines incisors in two different steps.

Treatment:

Procedure: Two-Step Retraction