Protocol for obtaining a digital and physical three-dimensional color map of the skull based on the Hounsfield scale...

To develop and describe a reproducible protocol for generating both digital and physical three-dimensional color maps of the skull, translating Hounsfield Unit (HU) values from computed tomography (CT) scans, acknowledging that HU are standardized in multislice CT (MSCT) while cone-beam CT (CBCT) provides relative gray values ('pseudo-HU'), into an intuitive visual guide of bone density. Bone structures are segmented semi-automatically using region-growing algorithms and manual refinements. Voxel-based HU values are quantitatively analyzed and converted into a pseudo-continuous color scheme. This color map is fused onto the 3D surface model of the segmented skull. Finally, a physical, multi-color model is produced via 3D printing to provide a haptic planning tool. This protocol represents a significant step toward more precise and equitable craniomaxillofacial surgery. The resulting digital and physical models empower surgeons to manage anatomical complexity, enhance pre-operative planning and surgical training, and expand capabilities in resource-limited environments.