Mandibular Gonial Angle Measurement with Anatomical Precision in 3D Volume Rendered CT Images

Area of Science:

• Medical Imaging
• Anatomy
• Biotechnology

Background:

• Traditional cephalometric analysis relies on two-dimensional (2D) measurements, which can be limited in anatomical accuracy.
• Gonial angle measurement is crucial for assessing mandibular morphology in various clinical and anthropological contexts.

Purpose of the Study:

• To introduce a novel, simple, and reproducible method for measuring the gonial angle using open-source 3D Slicer software.
• To evaluate if a standardized three-dimensional (3D) approach can serve as a practical and accurate alternative to traditional 2D cephalometric techniques.

Main Methods:

• High-resolution head CT scans were imported into 3D Slicer (version 5.6.2).
• The mandible was reconstructed in 3D using the volume rendering module.
• A Python script calculated the angle between two defined three-point planes tangential to the mandibular body and ramus.

Main Results:

• The developed workflow allows for accurate and reproducible 3D gonial angle measurements.
• This method offers flexibility for real-time adjustments and repeated calculations.
• Enhanced anatomical accuracy was achieved compared to traditional cephalometric methods.

Conclusions:

• This 3D approach provides a practical, cost-free, and standardized technique for gonial angle measurement.
• Potential applications include orthognathic surgery planning, analysis of facial asymmetry, and anthropological studies of the mandible.