At the very end of the end credits of Rogue One there is a reference to the Disney Research Medusa Performance Capture system, I was not able to fully read it but it seems to me it was about "teeth reconstruction" or something like that... Can anyone confirm this or add some details?
You're probably correct. The Disney Reasearch team in Zurich published a paper not long ago about recent developments in Model-Based Teeth Reconstruction, and some of its authors are credited for creating some of the special effects in Rogue One, as well as being members of the Medusa project. The full article can be downloaded here; here's an outline and a video:
In recent years, sophisticated image-based reconstruction methods for the human face have been developed. These methods capture highly detailed static and dynamic geometry of the whole face, or specific models of face regions, such as hair, eyes or eye lids. Unfortunately, image-based methods to capture the mouth cavity in general, and the teeth, in particular, have received very little attention. The accurate rendering of teeth, however, is crucial for the realistic display of facial expressions, and currently, high quality face animations resort to tooth row models created by tedious manual work. [...] Our approach seamlessly integrates into photogrammetric multi-camera reconstruction setups for entire faces, but also enables high quality teeth modeling from normal uncalibrated photographs and even short videos captured with a mobile phone.