Using Headpose Vector and 2D Points to Compute Distances
You don't have enough information to calculate 3D points for anything--all your information is relative right now. You need something that establishes a measurement, and some way to determine depth. If you know how far a point is from the camera (or can estimate it), then you can at least start calculating locations of features you know to be within the vertical plane containing that point. Or if you know how large a feature is, then you can calculate the sizes of features also assumed to be in the same vertical plane.
Alternatively, if you can use information from other frames, then you can assume a rigid model for certain facial features and begin to make estimates, but it's still all scale-free until you can pin down a distance somewhere.