Skeletal and dental changes after rapid maxillary expansion: a computed tomography study

Area of Science:

• Orthodontics
• Craniofacial imaging
• Dental anthropology

Background:

• Rapid maxillary expansion (RME) is a common orthodontic procedure to correct transverse discrepancies.
• Assessing the skeletal and dental effects of RME is crucial for treatment planning and outcome evaluation.

Purpose of the Study:

• To investigate the skeletal and dental changes induced by rapid maxillary expansion.
• To evaluate the utility of computed tomography (CT) scans and three-dimensional (3-D) reconstructed images in assessing these changes.

Main Methods:

• Twenty patients undergoing RME had pre- and post-treatment CT scans.
• Coronal CT and 3-D volumetric images were used to measure skeletal and dental dimensions.
• Statistical comparison of pre- and post-treatment measurements was performed using the Wilcoxon signed ranks test.

Main Results:

• RME resulted in significant increases in maxillary alveolar width, maxillary base width, bicondylar width, bimaxillo-mandibular width, and maxillary width.
• The greatest transverse dental change was observed in the intermolar width at the crown.
• A significant decrease in the maxillary central incisor angle indicated increased inter-apical distance.

Conclusions:

• Volumetric 3-D CT scanning is a valuable tool for assessing skeletal and dental changes following RME.
• While RME induces significant skeletal and dental expansion, dental tipping appears to be the predominant factor contributing to the observed transverse changes.