Cumulative Inaccuracies in Implementation of Additive Manufacturing Through Medical Imaging, 3D Thresholding, and 3D Modeling: A Case Study for an End-Use Implant

Abstract

In craniomaxillofacial surgical procedures, an emerging practice adopts the preoperative virtual planning that uses medical imaging (computed tomography), 3D thresholding (segmentation), 3D modeling (digital design), and additive manufacturing (3D printing) for the procurement of an end-use implant. The objective of this case study was to evaluate the cumulative spatial inaccuracies arising from each step of the process chain when various computed tomography protocols and thresholding values were independently changed. A custom-made quality assurance instrument (Phantom) was used to evaluate the medical imaging error. A sus domesticus (domestic pig) head was analyzed to determine the 3D thresholding error. The 3D modeling error was estimated from the computer-aided design software. Finally, the end-use implant was used to evaluate the additive manufacturing error. The results were verified using accurate measurement instruments and techniques. A worst-case cumulative error of 1.7 mm (3.0%) was estimated for one boundary condition and 2.3 mm (4.1%) for two boundary conditions considering the maximum length (56.9 mm) of the end-use implant. Uncertainty from the clinical imaging to the end-use implant was 0.8 mm (1.4%). This study helps practitioners establish and corroborate surgical practices that are within the bounds of an appropriate accuracy for clinical treatment and restoration.

3D printed plates based on generative design biomechanically outperform manual digital fitting and conventional systems printed in photopolymers in bridging mandibular bone defects of critical size in dogs

“…The introduction of additive manufacturing in a clinical setting, especially for craniomaxillofacial implants, requires tools that are sufficiently precise and accurate to match patient-specific and anatomical free-form geometries ( 48 ). CBCT is the latest technology in veterinary diagnostic imaging, having been used in human medicine as state of the art in dentistry and oral and maxillofacial surgery for several years.…”

3D Printed Models—A Useful Tool in Endovascular Treatment of Intracranial Aneurysms

“…In our study, we used 0.5 mm thickness images, and the postprocessing was made by radiologists as suggested by Akmal et al [ 18 ] and Huotilainen et al [ 19 ], ensuring that the interpretation of the images matches the 3D printed model and the structures are being well-differentiated from imaging modality artifacts. For postprocessing, we used 3D Slicer, an open-source software [ 7 ] that has been found to be suitable for segmentation as well as in other studies with 3D printing [ 15 , 20 ] because it is free and certified for medical use.…”

A Framework for Investigating the Adoption of Key Technologies: Presentation of the Methodology and Explorative Analysis of Emerging Practices

“…Case studies help to explain both the process and the outcome of a phenomenon through the observation, reconstruction, and analysis of the cases under investigation [96]. For this reason, scientific research often presents case studies in which key technologies are implemented and this can be useful for generalizing emerging practices [97].…”