Dimensional accuracy of medical models of the skull produced by three-dimensional printing technology by advanced morphometric analysis

Abstract

Introduction: Three-dimensional (3D) printing creates a design of an object using software, and the process involves by converting the digital files with a 3D data using the computer-aided design into a physical model. The aim of the study was to investigate the accuracy of human printed 3D skull models from computed tomography (CT) scan data via a desktop 3D printer, which uses fused deposition modeling (FDM) technology. Material and Methods: Human anatomical cadaver skulls were CT scanned in 128-slice CT scanner with a slice thickness of 0.625 mm. The obtained digital imaging and communications in medicine files were converted to 3D standard tessellation language (STL) format by using MIMICS v10.0 software (Materialise, Leuven, Belgium) program. The 3D skull model was printed using a Creatbot DX desktop 3D FDM printer. The skull model was fabricated using polylactic acid filament with the nozzle diameter of 0.4 mm and the resolution of the machine was maintained at 0.05 mm. The accuracy was estimated by comparing the morphometric parameters measured in the 3D-printed skull with that of cadaver skull and with CT images to ensure high accuracy of the printed skull. Fourteen morphometric parameters were measured in base and cranial fossa of the skull based on its surgical importance. Results: Analysis of measurements by inferential statistical analysis of variance for all three groups showed that the 3D skull models were highly accurate. Reliability was established by interobserver correlation for measurements on cadaver skull and the 3D skulls. Dimensional error was calculated, which showed that the errors between three groups were minimal and the skulls were highly reproducible. Discussion and Conclusion: The current research concludes that a 3D desktop printer using FDM technology can be used to obtain accurate and reliable anatomical models with negligible dimensional error.