(PR160) Use of Minimum Intensity Projection in a Limited Region of Interest around a Root Crack for Enhanced Crack Visualization: A Pilot Study

Objective: This study aims to determine if using a minimum intensity projection (MIP) in a focused region of interest (ROI) around suspected root cracks in teeth offers an advantage over routine CBCT image surveys.

Methods: High-resolution CBCT imaging (80-micron voxel size) was conducted on three human molars with desiccation-induced root cracks in a mandible, followed by micro-CT imaging (10-micron voxel size) as the gold standard. Only minor cracks visible in micro-CT but not CBCT images were included (n=7). DICOM images were analyzed with two 3D morphometry and densitometry software programs: CTAn and Scanco. A single evaluator marked ROIs around suspected cracks on selected slices, which were extended by five slices, and MIPs were generated in axial, transverse, and sagittal planes. The MIP images were evaluated for crack presence using color-rendered pixel intensities.

Results: When using the Scanco software, two suspected cracks were correctly reclassified from “Absent” to “Probably Present” and two more to “Crack Present.” CTAn did not show a similar advantage. Intraoperative agreement was 0.7.

Conclusion: The results suggest that MIP applied to a targeted ROI can enhance crack identification in CBCT images, though its effectiveness may vary depending on the software used.