Clinical Application of 3D-Printed Patient-Specific Instruments in Nasal Bone Fracture Reduction: A Randomized Controlled Trial.

To investigate the efficacy of a 3D-printed reduction instrument for nasal bone reduction, comparing it with conventional Boies elevators. A prospective, randomized, controlled trial was conducted on 78 patients with nasal bone fractures at Shanghai Ninth People's Hospital (2017-2020). Patients were assigned to either the 3D group (3D-printed reduction instrument, n = 39) or the BE group (Boies elevators, n = 39). Preoperative and postoperative nasal alignment and fracture parameters were analyzed using Mimics software, while patient satisfaction was assessed via a visual analog scale (VAS). Postoperative condition was graded using CT imaging. Statistical comparisons were performed using t-tests, Mann-Whitney U tests, and generalized estimating equations. Both groups showed significant improvements in fracture displacement (BE: 1.94-1.12 mm, 3D: 1.93-0.90 mm, p = 0.000), fracture angle (BE: 151.79°-169.91°, 3D: 149.34°-177.47°, p = 0.000), and midline displacement (BE: 7.79-4.42 mm, 3D: 7.44-0.00 mm, p = 0.000). The 3D group demonstrated significantly better postoperative midline displacement (p = 0.007), fracture angle (p = 0.003), and overall postoperative condition (p = 0.029). However, there was no significant difference in postoperative patient satisfaction scores (nasal obstruction: p = 0.053; nasal appearance: p = 0.318). The 3D-printed reduction instrument provides superior anatomical reduction and postoperative outcomes compared to Boies elevators. While both techniques effectively improve nasal alignment, patient satisfaction did not significantly differ. The 3D instrument offers a promising alternative when precision is required in nasal bone reduction.