A cleaned and repaired scan of Halloween prop skull with pointed, vampire-like teeth on both the upper and lower jaws. The scan was taken using 123D Catch and is available here in raw form. The creation of this scan (and tips for doing it yourself) is featured in the "Scanning in 3D" chapter of Getting Started with MakerBot. Also appearing in Make: Ultimate Guide to 3D Printing 2014.

The pictures show the scan printed in yellow Ultimachine PLA.
Print temp (extruder): 210
HBP: 50
Layer height: .25mm
If you are using PLA on a Replicator, print using the default settings (with the modifications stated above) without acceleration. Although it makes for a very long print, I found that the layers on the top of the skull came out better (were more uniform) if I printed at the Replicator default speeds.
UPDATE: I find that printing this with 13% infill and three extra shells works well when printing this at larger sizes. You may want to reduce the number of shells if printing it a very small scale.