# Effectiveness of Different Acceleration Methods for the En Masse Retraction of Upper Anterior Teeth: A Systematic Review and Meta-Analysis

## TL;DR

This review compares methods to speed up orthodontic tooth movement, finding that flapless corticotomy with laser therapy shows the most promise.

## Contribution

The study provides a systematic comparison of acceleration methods for en masse retraction using high-quality evidence from recent trials.

## Key findings

- Flapless corticotomy combined with low-level laser therapy increased retraction by 43.8% compared to conventional methods.
- Corticoalveolar perforations and electrical stimulation showed moderate acceleration but with low-quality evidence.
- Platelet-rich plasma injections did not provide meaningful benefits for retraction speed.

## Abstract

En masse retraction of the anterior teeth following first premolar extraction is a common orthodontic approach for correcting Class II malocclusion and bimaxillary protrusion. Several acceleration techniques have been proposed to reduce treatment duration, yet their comparative effectiveness remains uncertain. This systematic review evaluated randomized controlled trials published between January 1995 and May 2025 that investigated surgical, physical, mechanical, biochemical, hormonal, and pharmacological methods for accelerating en masse retraction in healthy orthodontic patients, with outcomes reported as the rate of retraction in millimetres per month. Six electronic databases and manual reference searches were screened, and the risk of bias was assessed using the Cochrane risk of bias 2 (RoB 2) tool. Nine trials involving 347 participants (mean age 21.6±2.97 years) met the inclusion criteria. One study was rated as high risk of bias, four had some concerns, and the remainder were rated as low risk. Flapless corticotomy increased the retraction rate by an average of 0.24 mm/month compared with conventional treatment (moderate‑quality evidence), while its combination with low‑level laser therapy produced the greatest and most sustained acceleration, achieving a 43.8% higher rate than conventional protocols (high‑quality evidence). Corticoalveolar perforations increased the rate by 0.28 mm/month (low‑quality evidence), and low‑intensity electrical stimulation accelerated retraction by approximately 28% (low‑quality evidence). Platelet‑rich plasma injections showed no meaningful benefit. Overall, flapless corticotomy, particularly when combined with low‑level laser therapy, appears to be a promising method for accelerating en masse retraction, offering clinically relevant reductions in treatment duration. However, these findings should be interpreted with caution due to the limited and heterogeneous evidence base, with most techniques supported by low‑to‑moderate quality evidence. The current data do not allow definitive conclusions regarding the superiority of one technique over another.