Extracted from my dental X-ray. Candy bowl added for utility.
Dental X-ray exported to DICOM data.
Choose a mask in InVesalius and export to STL.
Import the STL into MeshMixer for cleanup.
Print on a 3D printer (This one was made on a Replicator 2).
More details on the data extraction process: http://hackerfriendly.com/memento-mori/