Comparison of trabecular bone structure using fractal dimension analysis in patients undergoing lateral window and transcrestal sinus lift procedures: a retrospective cohort study
Özet
Background This retrospective study evaluated alterations in trabecular bone structure after lateral window and transcrestal sinus floor elevation techniques using fractal analysis of panoramic radiographs, with a focus on comparing ossification patterns. Materials and methods This STROBE compliant retrospective radiographic cohort included 46 sinus lift procedures (transcrestal without graft: n = 21; lateral window with xenograft: n = 25) performed between 2020 and 2024. For each case, two panoramic radiographs were analyzed on the surgery week (T0) and at 6 months (T1) yielding 92 images. Regions of interest (30 x 30 px) were placed apical to the implant site. Images were pre-processed according to the White-Rudolph protocol, and fractal dimension (FD) was calculated in ImageJ using the box-counting method. Normality was confirmed; paired t-tests assessed within-group change and independent t-tests compared groups. Intra-rater reliability was evaluated using the intraclass correlation coefficient. Results In the transcrestal group, a significant increase in FD values was observed between T0 and T1 (p < 0.001). In contrast, the lateral window approach group showed a statistically significant decrease in FD values over time (p = 0.0032). The FD values in the lateral window approach group were significantly higher than in the transcrestal group at both T0 (p < 0.001) and T1 (p = 0.009). Conclusion Fractal analysis demonstrated distinct bone remodeling patterns between transcrestal and lateral window sinus lifting techniques. In the transcrestal group, the natural healing process was characterized by more consistent increases in FD values, whereas xenograft-associated remodeling in the lateral window group was accompanied by a decline. These findings underscore the potential of fractal analysis as a non-invasive modality for monitoring bone quality following augmentation. Clinical trial number Not applicable.
