A comparison of panoramic views reformatted from CBCT scans using manual or automated workflows: an evaluation of geometric accuracy and subjective image quality.

OBJECTIVES: This study aimed to compare (1) the geometric accuracy and (2) subjective image quality of CBCT reformatted panoramic images generated using three reconstruction workflows: automatic reconstruction, nasal spine plane-oriented manual reconstruction, and occlusal plane-oriented manual reconstruction. MATERIALS AND METHODS: Twenty-eight CBCT datasets were included. Three panoramic reconstruction protocols were assessed. Linear measurements were obtained on axial images (as a reference) and on the corresponding reformatted panoramic images. Measurements included (for geometric accuracy): mesiodistal crown width of a selected maxillary central incisor; inter-radicular distance at the alveolar crest between adjacent anterior teeth; and panoramic interslice distance (PISD), defined as the distance between the primary panoramic line (center of the panoramic curve) and the secondary panoramic line at the measurement site. A 7-item binary visual scoring system was used to compare subjective image quality across protocols. RESULTS: Crown-level measurements differed significantly between axial images and reformatted panoramic images across all protocols. Bone-level measurements showed significant differences in G1 and G3, while there was no significant difference in the G2 protocol. In all groups, measurement error (absolute and percentage) showed a significant positive correlation with PISD. Subjective image quality scores differed across protocols. CONCLUSIONS: CBCT-reformatted panorama demonstrated protocol-dependent differences for linear measurements and subjective image quality. Measurement errors increased as the measurement sites deviated from the center of the drawn panoramic curve. CLINICAL RELEVANCE: Reformatted panorama requires cautious interpretation and should not be relied upon for precise quantitative assessments. Cross-verification with other views is essential before definitive clinical decisions.