Use of shape correspondence analysis to quantify skeletal changes associated with bone-anchored Class III correction

Area of Science:

• Orthodontics
• Craniofacial Surgery
• Biomedical Engineering

Background:

• Skeletal Class III malocclusion presents significant challenges in pediatric patients.
• Effective management often requires early intervention to guide facial growth.
• Bone-anchored maxillary protraction (BAMP) is an emerging technique for Class III correction.

Purpose of the Study:

• To quantitatively assess three-dimensional (3D) skeletal modifications in the mandible of Class III patients treated with BAMP.
• To utilize shape correspondence analysis for detailed evaluation of mandibular changes.

Main Methods:

• Twenty-five Class III patients (ages 9-13) underwent BAMP using miniplates and elastics.
• Cone-beam computed tomography (CBCT) scans were acquired before treatment (T1) and after 1 year (T2).
• 3D models were analyzed using shape correspondence analysis to measure skeletal displacements and angular changes.

Main Results:

• BAMP induced significant anteroposterior and vertical mandibular skeletal changes.
• Distal displacement of the posterior ramus (3.6 mm) and downward displacement of the mandibular lower border (menton: 2.6 mm, gonion: 3.6 mm) were observed.
• Condylar displacement averaged 2.6 mm, with patterns including backward, backward-downward, and backward-upward movement.

Conclusions:

• Bone-anchored maxillary protraction effectively controls mandibular growth patterns in Class III patients.
• This approach is a viable option for managing mandibular prognathism components.
• The study highlights the potential of BAMP in guiding skeletal development.