Analysis of Three-Dimensional Tooth Movement: A Comparative Study Between Digital Dental Models and Craniofacial...

Area of Science:

• Orthodontics
• Dental Imaging
• Biomedical Engineering

Background:

• Assessing orthodontic tooth movement (TM) traditionally relies on methods like computed tomography (CT).
• Digital dental models (DM) offer a non-invasive alternative for 3D analysis.
• Validating new reference regions is crucial for improving TM assessment accuracy.

Purpose of the Study:

• To validate the efficacy of digital dental models (DM) using a palatal region of interest (PROI) for assessing orthodontic tooth movement (TM).
• To compare the accuracy and reproducibility of DM/PROI with computed tomography (CT) using a cranial region of interest (CROI).

Main Methods:

• Thirty-four patients with jaw deformities underwent both DM and CT scans pre- and post-orthognathic treatment.
• Three-dimensional linear and angular measurements of tooth movement were performed using both DM and CT data.
• Reproducibility and agreement between DM and CT measurements were assessed using standard errors and Bland-Altman analysis.

Main Results:

• DM analysis with PROI registration showed high reproducibility with minimal standard errors (<0.15 mm for displacement, 0.43° for angular change).
• CT analysis with CROI registration also demonstrated high reproducibility (standard errors <0.20 mm).
• Bland-Altman analysis confirmed agreement between DM and CT linear changes, with limits of agreement below 0.91 mm.

Conclusions:

• The palatal region of interest (PROI), specifically the third palatal rugae and horizontal palatal vault, is a reliable reference for evaluating 3D tooth movement.
• Digital dental models provide advantages such as no X-ray exposure and no metal artifacts.
• The demonstrated precision and reproducibility support the clinical utility of DM/PROI in orthodontic treatment planning and assessment.