# Position of Maxillary Lateral Incisor and First Premolar in Impaction of Maxillary Canines: A Controlled Clinical CBCT and 3D Study Model Analysis

## TL;DR

This study used 3D models and CBCT scans to analyze how impacted maxillary canines affect the positions of nearby teeth and found specific patterns in tooth rotation and angulation.

## Contribution

The study introduces new insights into how impacted canines influence adjacent teeth positions using 3D and CBCT analysis.

## Key findings

- Impacted canines caused increased rotation and angulation in lateral incisors and first premolars.
- Buccally impacted canines led to greater positional changes in lateral incisors compared to palatally impacted ones.
- Mucosal bulges were linked to canines located within 1.2 mm of the outer bone surface.

## Abstract

Objectives: This study examined the link between impacted maxillary canines and changes in the position of adjacent lateral incisors (LIs) and first premolars (FPs), as well as opposite canines. It also explored the relationship between the position of impacted canines and the presence of palpable mucosal bulges. Methods: The clinical study involved 62 participants (35 females, 27 males; average age: 14.7 years), split equally into impacted canine (n = 31) and control (n = 31) groups. The study included 26 palatally impacted canines, 5 buccally impacted canines, 31 non-impacted contralateral canines, and 62 control canines. Three-dimensional study models assessed LI and FP positions, while CBCT analyzed vertical and horizontal positions of impacted canines and dental follicles. Clinicians evaluated the presence of mucosal bulges, and distance was measured between impacted canines and outer cortical bone radiographically. Results: Compared to controls, the LIs next to impacted canines showed significantly more rotation (13°), mesiodistal angulation (11.5°), and buccopalatal angulation. FPs showed increased rotation (10.0°) and mesiodistal angulation (8.7° more) but no change in buccopalatal inclination. Contralateral canines had significantly more rotation (11.3°) than controls. Buccally impacted canines led to greater positional differences in the LIs compared to palatally impacted canines. Follicle thickness had a moderate correlation with FP rotation and mesiodistal angulation but did not relate to LI malposition. Visible mucosal bulges indicated distances of 1.2 mm or less between the canine and cortical bone. Conclusions: This study found positional differences in lateral incisors showed altered rotation, angulation, and inclination, while first premolars had increased rotation and angulation. Buccally impacted canines showed more discrepancies for lateral incisors. A mucosal bulge may indicate impacted canine location if the impacted canine is close to the outer bone surface. Follicle thickness affected premolar position but not incisors.