ArticleCureus2026
Comparison of En Masse Retraction and Two-Step Retraction Mechanics in Class I Bimaxillary Protrusion: A Retrospective Comparative Study.
Article in Cureus, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
introductionBimaxillary protrusion is commonly treated using extraction-based orthodontic therapy, followed by anterior tooth retraction. En masse retraction and two-step retraction are widely used space-closure mechanics; however, differences in treatment efficiency, anchorage preservation, and arch dimensional changes remain. This study aimed to compare the outcomes of en masse retraction and two-step retraction mechanics in patients with Class I bimaxillary protrusion undergoing extraction-based orthodontic treatment. MATERIALS AND
methodsThis retrospective comparative study evaluated the completed orthodontic records of 100 patients with Class I bimaxillary protrusion who were treated between 2016 and 2021. The patients were classified into two groups: en masse retraction (n = 50) and two-step retraction (n = 50). Measurements were obtained from the pretreatment and post-treatment study models and treatment records. The variables assessed were maxillary incisor retraction, anchorage loss, treatment duration, retraction rate, extraction space closure efficiency, residual extraction space, and transverse arch dimensional changes. Data were analyzed using an independent samples t-test, a chi-square test, and a Mann-Whitney U test. Statistical significance was set at p < 0.05.
resultsBoth treatment modalities achieved comparable maxillary incisor (6.84 ± 1.12 mm vs. 6.52 ± 1.08 mm; p = 0.129). The en masse retraction group demonstrated significantly greater anchorage loss, with a first molar mesial drift of 2.18 ± 0.76 mm compared with 1.43 ± 0.61 mm in the two-step retraction group (p < 0.001). Space closure duration was significantly shorter in the en masse group (8.6 ± 1.8 months) than in the two-step group (11.4 ± 2.3 months) (p < 0.001). Extraction space closure efficiency was higher in the en masse group (96.90 ± 2.80%) than in the two-step group (95.40 ± 3.20%) (p = 0.011). Significant reductions in intercanine, intermolar, and interpremolar widths were observed in the en masse group compared with the two-step group (p < 0.001).
conclusionBoth retraction mechanics were effective in achieving anterior tooth movement. En masse retraction provided faster space closure and greater treatment efficiency but was associated with increased anchorage loss and greater transverse arch constriction. Two-step retraction demonstrated superior anchorage preservation and transverse dimension stability.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.