# Three-dimensional assessment of low-level laser therapy on orthodontic miniscrew displacement using CBCT: a retrospective study

## TL;DR

This study used 3D imaging to find that low-level laser therapy does not significantly affect orthodontic miniscrew displacement during canine retraction.

## Contribution

The novel contribution is a 3D assessment of LLLT's effect on orthodontic miniscrew displacement using CBCT in a clinical setting.

## Key findings

- LLL application did not significantly affect miniscrew displacement in any spatial plane.
- Miniscrews on both laser-treated and control sides showed significant three-dimensional displacement.
- No significant difference in displacement was found between laser-treated and control sides in any plane.

## Abstract

This study aimed to assess the effect of Low-Level Laser Therapy (LLLT) on sagittal, transverse and vertical Orthodontic miniscrew displacement.

The study included CBCTs from the records of 12 adult patients who underwent upper first premolar extraction and canine retraction with orthodontic miniscrews for maximum anchorage. The miniscrews on one side received LLL, while the other side served as a control. The Low-Level Laser was applied to assess its effect on the displacement of the miniscrews. The used CBCTs have been taken at two-time points: immediately after miniscrew insertion (T0) and four months after the start of canine retraction (T1) with a total of 24 CBCTs. Miniscrew displacement was assessed by measuring head (HMS) and tail (TMS) displacement to the axial, coronal and mid-sagittal planes on the CBCT at the two time points. Miniscrews displacement (T1-T0) was compared between LLL side and control side. Comparisons were performed using paired samples t-test. The significance level was set at p-value < 0.05. The reproducibility of measurements was assessed by intraclass correlation coefficient (ICC).

After four months of canine retraction, HMS and TMS from both laser and control sides showed significant three-dimensional displacement at p < 0.05. No significant difference in mean displacement in the vertical, sagittal, nor transverse planes between both sides was elicited.

LLL application in the used protocol does not affect the amount of miniscrew displacement in any of the three planes of space. Miniscrew displacement was significant in both groups.