# Volumetric changes in the maxillary sinus following orthodontic disimpaction of unilaterally impacted maxillary canines: a prospective CBCT-based split-mouth study

## TL;DR

This study found that orthodontic treatment of impacted maxillary canines can increase the volume of the maxillary sinus, with palatally impacted canines showing greater changes.

## Contribution

The study provides new empirical evidence on how orthodontic disimpaction affects maxillary sinus volume and identifies predictors of volume normalization.

## Key findings

- Orthodontic disimpaction of unilaterally impacted maxillary canines significantly increased maxillary sinus volume.
- Palatally impacted canines showed greater pretreatment sinus volume compared to buccally impacted canines.
- Younger age, palatal impaction, shorter treatment duration, and pretreatment volume differences were significant predictors of volume normalization.

## Abstract

The relationship between orthodontic disimpaction of unilaterally impacted maxillary canines (MCs) and volumetric changes in the maxillary sinus (MS) remains underexplored.

This study aimed to evaluate MS volume alterations following orthodontic traction of impacted MCs, using cone-beam computed tomography (CBCT). Additionally, it examined differences based on the impaction site (buccal vs. palatal) and sex.

A prospective split-mouth study was conducted on patients with unilaterally impacted MCs. CBCT scans were taken before and after orthodontic disimpaction. MS volume was measured using three-dimensional reconstruction software. Comparisons were made between the impacted and non-impacted sides, buccal and palatal impactions, and male and female patients. Statistical analysis included paired t-tests and analysis of variance (ANOVA) for group comparisons. A multifactorial regression analysis was performed to identify predictor variables influencing MS volume normalization.

A significant increase in MS volume was observed on the previously impacted side, following orthodontic disimpaction (p < 0.05). Buccally impacted MCs showed greater pretreatment sinus volume, compared to palatally impacted MCs. Additionally, statistically significant sex-based differences were not noted, in the relative volumetric change between sexes (p > 0.05). It was indicated by our study that younger age, palatally impacted MCs, shorter treatment duration, increased distance of the root tip of impacted MC from MS floor, and pretreatment MS volume differences were significant predictors of MS volume normalization.

Orthodontic disimpaction of unilaterally impacted MCs influenced MS volume, with greater mean change of MS volume in palatal impactions.