Accuracy of measurements on CBCT-generated digital models using different exposure parameters (in vitro study)

Area of Science:

• Dental radiology
• Biomedical imaging
• Orthodontics

Background:

• Dental imaging modalities vary in diagnostic features and are influenced by numerous parameters.
• Accurate dental evaluations and treatments depend on the precision and effectiveness of imaging techniques.
• Cone-beam computed tomography (CBCT) is a key dental imaging modality.

Purpose of the Study:

• To examine the dimensional reproducibility of arch measurements from CBCT scans.
• To compare CBCT scans with varying voxel sizes and exposure parameters against extra-oral scanner (EOS) reference models.
• To assess the impact of CBCT parameters on digital matching and diagnostic image quality.

Main Methods:

• A diagnostic observational study was conducted on digital models derived from 65 CBCT scans of a maxillary model.
• Arch dimensions (inter-canine, inter-premolar, intermolar, arch width, arch length) were measured.
• Measurements from EOS scans served as the control; statistical analysis included Shapiro-Wilk and Kruskal-Wallis tests.

Main Results:

• Significant deviations in arch measurements were observed across different CBCT parameter groups.
• The group with the smallest voxel size (0.12 mm) showed the lowest deviation (mean 0.01 mm).
• The group with the lowest kilovoltage (kV) value exhibited the highest deviations (mean 0.16 mm).

Conclusions:

• Combining small voxel size (0.12 mm) with high milliampere (8 mA) and kilovoltage (90 kV) settings in CBCT yields accurate linear measurements.
• This parameter combination ensures detailed anatomical visualization crucial for precise dental assessments.
• Strict control over CBCT parameters is essential for reliable dental applications and treatment outcomes.