Effectiveness of Physical Methods in Accelerating Upper Canine Retraction: A Systematic Review and Meta-Analysis of...

Area of Science:

• Orthodontics
• Biotechnology
• Dental Research

Background:

• Orthodontic treatments for maxillary canine retraction are often lengthy, impacting patient experience.
• There is increasing interest in physical modalities to accelerate tooth movement.
• Low-level laser therapy (LLLT), mechanical vibration, and electromagnetic fields are being explored.

Purpose of the Study:

• To systematically evaluate and compare the effectiveness of LLLT, mechanical vibration, and electromagnetic fields in accelerating maxillary canine retraction.
• To assess the impact of these physical modalities on secondary outcomes like canine angulation, rotation, anchorage loss, and root resorption.

Main Methods:

• A comprehensive electronic search of six databases was performed up to July 5, 2025.
• Included were randomized controlled trials (RCTs) comparing physical modalities with standard orthodontic controls.
• Meta-analyses were conducted to determine mean differences in retraction rates and assess heterogeneity.

Main Results:

• LLLT significantly increased canine retraction rate (MD = 0.43 mm/month, p = 0.007), with sensitivity analysis yielding MD = 0.26 mm/month.
• Mechanical vibration also significantly accelerated retraction (MD = 0.36 mm/month, p < 0.00001) with no heterogeneity.
• Electromagnetic fields showed positive but limited evidence; no significant adverse effects were observed for secondary outcomes.

Conclusions:

• Physical modalities, particularly LLLT and mechanical vibration, can moderately accelerate maxillary canine retraction.
• These methods appear to be safe, with no detectable adverse effects on canine angulation, rotation, anchorage, or root integrity.
• Further high-quality RCTs with standardized protocols are recommended for routine clinical application due to protocol variability and limited long-term data.