Trabecular bone remodelling following lateral window maxillary sinus augmentation with allograft versus xenograft: a retrospective one-year comparative fractal dimension analysis.
TL;DR
Allografts produced higher early-phase FD values, while both materials achieved comparable radiographic trabecular complexity by the 6-month and 1-year follow-up periods, which suggest convergent radiographic remodelling over time.
Abstract
Background
Maxillary sinus augmentation is widely performed to enable implant placement in the atrophic posterior maxilla, and the radiographic remodelling patterns of different graft materials remain a topic of clinical interest. This retrospective study compared trabecular bone remodelling following lateral window maxillary sinus augmentation with allograft versus xenograft materials using FD analysis of panoramic radiographs over a one-year follow-up.
Methods
One hundred patients (50 allograft, 50 xenograft) treated between 2015 and 2023 were included. Panoramic radiographs obtained immediately postoperatively and at 3 months, 6 months, and 1 year were analyzed using ImageJ software according to the White and Rudolph box-counting method. Intragroup temporal changes were evaluated with the Friedman test and Bonferroni-corrected Wilcoxon signed-rank tests; intergroup comparisons were performed using the Mann-Whitney U test or independent samples t-test according to data distribution. Interobserver reliability was assessed using the intraclass correlation coefficient (ICC).
Results
Age and sex distributions were comparable between groups (p = 0.250 and p = 0.288, respectively). FD values changed significantly over time in both the allograft (p = 0.021) and xenograft (p < 0.001) groups. In the allograft group, only the 3-month versus 6-month comparison reached significance (p = 0.001), whereas in the xenograft group all pairwise comparisons except 6 months versus 1 year were significant. Intergroup comparisons revealed significantly higher FD values in the allograft group immediately postoperatively (p = 0.010) and at 3 months (p < 0.001), but no differences were detected at 6 months (p = 0.107) or 1 year (p = 0.751). Interobserver reliability was good across most measurements (ICC 0.794-0.856), with moderate reliability for the 6-month xenograft measurement (ICC = 0.744).
Conclusions
Allografts produced higher early-phase FD values, while both materials achieved comparable radiographic trabecular complexity by the 6-month and 1-year follow-up periods. These findings suggest convergent radiographic remodelling over time. Further histomorphometric and clinical studies are needed to confirm these FD-derived findings. TRIAL REGISTRATION Not applicable.