3D printing for orbital volume anatomical measurement

Abstract

Purpose: The aim was to develop a method for reproducible orbital volume (OV) measurement in vivo based on 3D printing.

Methods: Twelve orbits were obtained from dry skulls of the Human Anatomy Department of Lille University. Computer tomography (CT) slice images of these orbits were transformed into stereo-lithography (STL) format and 3D-printed. Bone openings were closed using either putty and cellophane after printing (3D-Orb-1) or at the printing stage in silico using MeshMixer (3D-Orb-2). The results were compared with those of the conventional water-filling method as a control group (Anat-Orb).

Results: The observers reported a mean orbital volume of 21.3 ± 2.1 cm³ for the open-skull method, 21.2 ± 2.4 cm³ for the non-sealed 3D-printing method, and 22.2 ± 2.0 cm³ for the closed-print method. Furthermore, the intraclass correlation coefficients (ICCs) showed excellent intra-rater agreement, i.e., an ICC of 0.994 for the first observer and 0.998 for the second, and excellent interobserver agreement (ICC: 0.969). The control and 3D-Orb-1 groups show excellent agreement (ICC: 0.972). The 3D-Orb-2 exhibits moderate agreement (ICC: 0.855) with the control and appears to overestimate orbital volume slightly.

Conclusion: Our 3D-printing method provides a standardized and reproducible method for the measurement of orbital volume.

Keywords: 3D print; Orbit; Orbital volume; Skull.