Patient-Specific Augmentation Rhinoplasty Using a Three-Dimensional Simulation Program and Three-Dimensional Printing

Overview

Augmentation rhinoplasty adds height to the nose, and choosing the material and shape has long been done by hand. This study tested a system that designs an implant from the patient's own CT scan, 3D prints a negative mold, and casts silicone in it. The aim was to check whether the manufactured implant reproduces the design.

Sections of note

• Implants were designed with an in-house program using preoperative computed tomography.
• Negative molds were fabricated by a 3D printer and silicone injected into them.
• 10 actual silicone implants were made and compared against the virtual designs.
• Reproduction accuracy was within 0.07 mm, a difference of 0.17 percent plus or minus 0.11 percent.
• Accuracy was highest at the upper end of the implant and fell toward the lower end: 100 percent at the most cephalic point, 57.1 and 71.4 percent at the right and left points at the lower end of the nasal bone, 28.6 percent at each supratip point, and 0 percent at the most caudal point.
• 7 patients underwent surgery, with postoperative CT to confirm implant positioning. Level of evidence 4.

What it means for a patient

• The manufacturing step is accurate, particularly toward the top of the bridge, and least accurate at the tip end.
• This tests whether the implant matches its design, not whether patients looked better or were satisfied.
• Only 7 patients were operated on, and no aesthetic outcomes, complications, or follow-up are reported.
• The implant here is silicone, a synthetic material, which carries the usual risks of infection, movement, and extrusion.

Why this paper matters

Custom implant fabrication would remove the hand carving step and its dependence on surgeon experience. This is a feasibility and accuracy study, which is the necessary first stage. Clinical outcomes and long-term implant behavior remain untested.

Terms

• Augmentation rhinoplasty: An operation adding height or volume to the nose.
• Patient-specific implant: An implant designed from an individual patient's own scan.
• Computed tomography: An X-ray scan producing cross-sectional images used to build 3D models.
• Negative mold: A hollow form into which material is cast to produce the final shape.
• Cephalic: Toward the head, meaning the upper end; caudal means the lower end.