An interventional study of En masse anterior teeth retraction and Two-Step Retraction in Malocclusion, Angle Class I, Bimaxillary Protrusion and Orthodontic Space Closure, sponsored by Rio de Janeiro State University. Status unknown at 1 site in Brazil. Open to participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2019-04-05.
Sponsored by Rio de Janeiro State University · Not applicable, Interventional, and Treatment
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.
35 studies on the registry are indexed under Malocclusion, Angle Class I; 10 are open to participants now.
This study's planned enrollment of 32 is close to the median of 32 across 31 interventional studies indexed under Malocclusion, Angle Class I.
Browse Malocclusion, Angle Class I studies →Rio de Janeiro State University is the lead sponsor of 62 studies on the registry; 6 are open to participants now.
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Exclusion Criteria:
Group treated by retracting the six anterior teeth simultaneously.
Procedure: En masse anterior teeth retraction
Group treated by retracting the canines incisors in two different steps.
Procedure: Two-Step Retraction
After extraction of the four premolars the posterior teeth will be tied-together and the six anterior teeth will be retracted by sliding mechanics.
After extraction of the four premolars the posterior teeth will be tied-together and the canines will be retracted by sliding mechanics. After the distalization of the canines they will be tied to the posterior teeth and the incisors will be retracted by sliding mechanics.
Anchorage loss
Quantitative assessment of posterior anchorage loss between the two groups as measured by tomographic superimposition at the end of space closure.
Time frame: 12 months
Anterior teeth retraction
Quantitative assessment of anterior teeth retraction between the two groups as measured by tomographic superimposition at the end of space closure.
Time frame: 12 months
Molar inclination
Quantitative assessment of molars inclination between the two groups as measured by tomographic superimposition at the end of space closure.
Time frame: 12 months
Canine inclination
Quantitative assessment of canines inclination between the two groups as measured by tomographic superimposition at the end of space closure.
Time frame: 12 months
Incisors inclination
Quantitative assessment of incisors inclination between the two groups as measured by tomographic superimposition at the end of space closure.
Time frame: 12 months
Started Apr 2019 (actual). Primary completion is estimated for Apr 2020, 12 months after the start.
Of 23 interventional studies with no phase under Malocclusion, Angle Class I, half reached primary completion within 21 months of starting (the median), counting those still running; a quarter within 15 and three quarters within 24. This study's planned 12 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is status unknown, as verified in Apr 2019. You cannot join it, but the record below documents what was studied.
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Rio de Janeiro State University