Related Experiment Video
Updated: May 10, 2026
Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition
Published on: February 23, 2024
Assessment of changes following en-masse retraction with mini-implants anchorage compared to two-step retraction with
Salma Al-Sibaie1, Mohammad Y Hajeer2
1*Department of Orthodontics, University of Al-Baath Dental School, Hamah and.
Background:
No randomized controlled trial has tried to compare treatment outcomes between the sliding en-masse retraction of upper anterior teeth supported by mini-implants and the two-step sliding retraction technique employing conventional anchorage devices.
Objective:
To evaluate skeletal, dental, and soft tissue changes following anterior teeth retraction.
Design And Setting:
Parallel-groups randomized controlled trial on patients with class II division 1 malocclusion treated at the University of Al-Baath Dental School in Hamah, Syria between July 2011 and May 2013.
Participants:
One hundred and thirty-three patients with an upper dentoalveolar protrusion were evaluated and 80 patients fulfilled the inclusion criteria. Randomization was performed using computer-generated tables; allocation was concealed using sequentially numbered opaque and sealed envelopes. Fifty-six participants were analysed (mean age 22.34 ± 4.56 years). They were randomly distributed into two groups with 28 patients in each group (1:1 allocation ratio).
Intervention:
Following first premolar extraction, space closure was accomplished using either the en-masse technique with mini-implants or the two-step technique with transpalatal arches (TPAs).
Main Outcome Measure:
The antero-posterior displacements of upper incisal edges and upper first molars were measured on lateral cephalograms at three assessment times. Assessor blinding was employed.
Results:
A bodily retraction (-4.42 mm; P < 0.001) with a slight intrusion (-1.53 mm; P < 0.001) of the upper anterior teeth was achieved in the mini-implants group, whereas upper anterior teeth retraction was achieved by controlled palatal tipping in the TPA group.
Conclusions:
When retracting anterior teeth in patients with moderate to severe protrusion, the en-masse retraction based on mini-implants anchorage gave superior results compared to the two-step retraction based on conventional anchorage in terms of speed, dental changes, anchorage loss, and aesthetic outcomes.
