Comprehensive smartphone-based 3D scanning framework for capturing the external ear

Congenital microtia manifests abnormalities in the external ear leading to potential adverse impacts on psychosocial health and hearing impairment. Three-dimensional (3D) technologies have demonstrated potential applications for personalised prosthesis fabrication; however, the large hardware costs limit their routine clinical use. Frugal 3D scan-model-print pipelines can disrupt traditional processes and increase accessibility. In this study, we aimed to further validate 3D photogrammetry using 3 different smartphone models. Both ears of 10 participants were scanned with 4 devices: Samsung Galaxy S8, Samsung Galaxy S9, Apple® iPhone 8S, and Artec Spider 3D scanner. Scan, processing times, accuracy, completeness, and repeatability of the smartphone models were analysed with no significant difference across all tested models (Accuracy: 1.1 ± 0.3 mm, Completeness: 81 ± 10%). This demonstrates a flexibility in capture device selection for smartphone photogrammetry, with the potential to broaden the translation of this frugal 3D scanning approach to personalised prosthesis production.