Post-Traumatic Orbital Reconstruction Using Titanium Patient-Specific Implants: A Clinical and Radiological Cohort Study Focusing on Paranasal Sinuses Physiology

<b>Background:</b> This longitudinal cohort study evaluated implant-associated bone remodeling and paranasal sinus (PNS) status after the insertion of patient-specific titanium orbital implants (PSIs) in adult trauma patients. Sixteen patients with various orbital fractures underwent CT-based reconstruction at the University Hospital Halle (Germany) and were followed up to 6.5 years (observation period February/2019-October/2025). Post-operative CT scans assessed orbital bone remodeling, patency of the ostiomeatal unit, and PSI/screw exposure. <b>Findings</b>: Bone apposition was observed in 16 cases; 13 showed a patent maxillary sinus outflow tract. The median Lund score for the injured sides was 1.0 vs. for the uninjured sides 0 (Wilcoxon test, <i>p</i> = 0.131). PSI or screw exposure occurred in isolated cases, and basal maxillary sinusitis was noted in four patients. Significant bone remodeling was detectable from 6 months post-operatively. No implant-associated complications required further intervention. <b>Conclusions and Relevance</b>: These findings highlight the safety and precision of PSIs, with low long-term complication rates and preserved sinus function in non-irradiated patients, supporting their use in complex orbital reconstructions.