Application and limitations of facial computed tomography and three-dimensional scanner images for patient-specific three-dimensional printing of a nose mask

Background: The applications of three-dimensional (3D) printing are expanding in personalized medicine. The image data used for 3D printing modeling include 3D scanners and medical image data such as computed tomography (CT) and/or magnetic resonance imaging data. Objective: To compare 3D scanner images with CT 3D images for fabricating a patient-specific nasal pillow positive airway pressure (PAP) mask using 3D printing technology. Methods: Personalized PAP masks were designed using 3D printing based on image data obtained using a low-dose facial CT scan or a 3D scanner. After converting the extracted nose shape data into a standard tessellation language file format, it was transferred to mesh-based modeling software (3-matic) to produce a PAP mask matching the shape of the nose. A questionnaire was used to evaluate the wearing sensation, degree of air leakage, and delivery ability of positive pressure for the customized and conventional nasal type masks. Each mask was rated between 0 and 4. Results: The ultra-low-dose CT scan with a 1-mm slice distance was adequate to obtain the clear images required to produce a 3D printed nasal pillow PAP mask. The wearing sensation of the 3D printed nasal pillow PAP masks tended to be more comfortable than that of the conventional nasal masks (p=0.056). However, the least amount of air leakage was observed with the conventional nasal mask (p=0.003). The positive pressure delivery ability was slightly lower in the 3D nasal pillow mask group (p=0.054). Conclusion: The nasal pillow type 3D printed PAP masks used in this study did not demonstrate satisfactory results to justify its use as a replacement of the conventional nasal-type mask. An ultra-low-dose CT scan was sufficient to produce a 3D printed mask.