Surface analysis of study models generated from OrthoCAD and cone-beam computed tomography imaging

Area of Science:

• Orthodontics
• Dental Imaging
• Digital Modeling

Background:

• Digital models are increasingly used in orthodontics for diagnosis and treatment planning.
• Cone-beam computed tomography (CBCT) offers a 3D imaging solution, but its accuracy for model generation needs evaluation.
• Comparison with established digital impression systems like OrthoCAD is crucial for clinical adoption.

Purpose of the Study:

• To determine the accuracy of digital models generated from cone-beam computed tomography (CBCT).
• To compare the accuracy of CBCT-generated models with OrthoCAD models for orthodontic applications.
• To assess model accuracy using surface area analysis and linear measurements.

Main Methods:

• Acquired two sets of maxillary and mandibular digital models from 30 subjects: one from OrthoCAD impressions, one from CBCT files.
• Superimposed matched pairs of models using a best-fit algorithm and performed surface-to-surface analysis.
• Measured average linear differences and surface correlation at various tolerance levels (0.25-1.5 mm); analyzed 6 linear measurements from landmarks.

Main Results:

• Average linear differences ranged from 0.28-0.60 mm for maxillary and 0.34-0.61 mm for mandibular models.
• Over 90% surface correlation was achieved at 1.00 mm for maxillary and 1.25 mm for mandibular models.
• Mean differences for linear measurements were 0.071 mm (maxillary) and 0.018 mm (mandibular).

Conclusions:

• Surface-to-surface analysis indicates a fair overlap between CBCT and OrthoCAD digital models.
• The accuracy of CBCT-generated digital models is sufficient for initial orthodontic diagnosis.
• CBCT models are adequate for orthodontic treatment planning, offering a viable alternative to traditional digital impressions.