Morphologic evaluation and classification of facial asymmetry using 3-dimensional computed tomography.

Area of Science:

• Craniofacial surgery
• Orthognathic surgery
• Medical imaging analysis

Background:

• Facial asymmetry requires systematic classification for effective diagnosis and surgical treatment.
• Objective classification based on skeletal characteristics is currently lacking.

Purpose of the Study:

• To analyze skeletal structures in patients with facial asymmetry.
• To develop an objective classification system for facial asymmetry based on structural characteristics.

Main Methods:

• Utilized 3D computed tomograms from 43 patients with facial asymmetry.
• Performed linear and angular measurements of maxillary and mandibular structures.
• Applied K-means cluster analysis to objectively classify patients into distinct groups.

Main Results:

• Four distinct groups of facial asymmetry were identified based on cluster analysis.
• Group 1: Mandibular body shift (44%).
• Group 2: Ramus height discrepancy with menton deviation (39%).
• Group 3: Atypical asymmetry (12%).
• Group 4: Severe maxillary canting and ramus height differences (5%).

Conclusions:

• Developed a statistically distinct, four-group classification for facial asymmetry.
• This classification system aids in diagnosis and treatment planning.
• Potential to explore the etiology of different facial asymmetry variants.