Three-dimensional mandibular characteristics in skeletal malocclusion : A cross-sectional study

Area of Science:

• Orthodontics and Dental Anthropology
• 3D Imaging in Medicine
• Craniofacial Morphology

Background:

• Skeletal malocclusions present complex challenges in orthodontic treatment planning.
• Understanding the interplay between skeletal patterns, gender, and mandibular morphology is crucial for accurate diagnosis.
• Previous studies have explored these relationships, but a comprehensive 3D analysis is needed.

Purpose of the Study:

• To investigate the correlation between skeletal malocclusions (transversal, sagittal, vertical), gender, and detailed mandibular characteristics in three dimensions.
• To identify specific mandibular features indicative of extreme skeletal patterns in adult patients.

Main Methods:

• A 3D skull model was created for 111 adult patients using CT/CBCT scans.
• Skeletal patterns were assessed using menton deviation (transversal), Wits appraisal (sagittal), and maxillomandibular plane angle (vertical).
• Linear, angular, and volumetric mandibular parameters were measured and analyzed.

Main Results:

• No correlation was found between transversal skeletal asymmetry and mandibular characteristics.
• Sagittal and vertical skeletal patterns significantly impacted mandibular morphology (p < 0.001).
• Gender independently correlated with mandibular characteristics. Class II/III malocclusions showed distinct ramus and body angles, while hypodivergent/hyperdivergent patterns differed in gonial angle, body angle, and body/mandibular volume.

Conclusions:

• Angular and volumetric mandibular characteristics are key indicators for identifying extreme sagittal and vertical malocclusions.
• Orthodontists should integrate these 3D mandibular analyses into treatment planning for adult patients.
• Gender-specific differences in mandibular morphology should also be considered in orthodontic diagnosis.