A Preliminary Investigation into the Accuracy of 3D Modeling and 3D Printing in Forensic Anthropology Evidence Reconstruction.

Rachael M Carew,Carolyn Rando,Ruth M Morgan

doi:10.1111/1556-4029.13917

Abstract

There is currently no published empirical evidence‐base demonstrating 3D printing to be an accurate and reliable tool in forensic anthropology, despite 3D printed replicas being exhibited as demonstrative evidence in court. In this study, human bones (n = 3) scanned using computed tomography were reconstructed as virtual 3D models (n = 6), and 3D printed using six commercially available printers, with osteometric data recorded at each stage. Virtual models and 3D prints were on average accurate to the source bones, with mean differences from −0.4 to 1.2 mm (−0.4% to 12.0%). Interobserver differences ranged from −5.1 to 0.7 mm (−5.3% to 0.7%). Reconstruction and modeling parameters influenced accuracy, and prints produced using selective laser sintering (SLS) were most consistently accurate. This preliminary investigation into virtual modeling and 3D printer capability provides a novel insight into the accuracy of 3D printing osteological samples and begins to establish an evidence‐base for validating 3D printed bones as demonstrative evidence.

Highlights

There is currently no published empirical evidence-base demonstrating 3D printing to be an accurate and reliable tool in forensic anthropology, despite 3D printed replicas being exhibited as demonstrative evidence in court
This study addresses the impact of different printer types and assesses the level of accuracy that is attainable in producing replicas of bones
Subjects can be distorted via the light or angle used in a photograph or a virtual rendering; second, when presenting a 3D object such as a bone as a 2D image, whether as a photograph or a virtual model, depth and spatial information is immediately lost [2,10]; and third, virtual 3D models are stereoscopic, meaning that they only give the illusion of depth

Summary

Introduction

There is currently no published empirical evidence-base demonstrating 3D printing to be an accurate and reliable tool in forensic anthropology, despite 3D printed replicas being exhibited as demonstrative evidence in court. Reconstruction and modeling parameters influenced accuracy, and prints produced using selective laser sintering (SLS) were most consistently accurate. This preliminary investigation into virtual modeling and 3D printer capability provides a novel insight into the accuracy of 3D printing osteological samples and begins to establish an evidence-base for validating 3D printed bones as demonstrative evidence. As a first step toward validating 3D printed replicas for use as evidence, this experimental study compares known bone samples with virtual and physical 3D models of those bones to investigate the accuracy and capabilities of these reconstruction techniques.

Methods

Results

Discussion

Conclusion