A comparison of the accuracy and feasibility of a low-cost mobile application versus higher-cost handheld 3D scanner for digital ear prosthetics

Background: Facial prosthetics are an important means to rehabilitate patients with congenital or acquired facial defects. However, with a time-consuming manual workflow and workforce shortage, access to facial prosthetics is limited in Australia and worldwide, especially for rural and remote patients. Optical 3D scanning has been increasingly integrated in digitizing data. With the development of TrueDepth® camera technology on smartphones, there is increasing availability of mobile applications which can generate 3D images to improve accessibility and reduce cost. This study compares the accuracy of mobile phone applications to high resolution 3D scanners for auricular data acquisition. Methods: We conducted a case–control study comparing the EM3D smartphone application (EM3D) with the EinScan Pro 2× Plus Shining 3D handheld scanner (EinScan) in 22 healthy participants equating to 44 ears, using CloudCompare software analysis. Results: On average, EM3D acquired images 2.5 minutes quicker than the EinScan. The mean absolute directional distance difference was 1.10 mm, within the accepted deviation range of 2 mm. Out of the 44 ears, only 1 ear (2.27%) did not meet the accepted value of accuracy within 2 mm. The average completeness was 85% and the overall quality of images obtained from EinScanand EM3D were 53.5% and 57.7%, respectively, through observational analysis. Conclusion: Mobile iPhone applications such as EM3D are a viable alternative to 3D handheld scanners such as EinScan. This study demonstrates reliable results in accuracy, and improved results in time, cost and operational feasibility.