A method and apparatus for determining a three dimensional orientation of a human head. The method includes first interposing a left and a right anthropological baselines on a patient s face each anthropological baseline connecting an orbitale point and an auricular point on a corresponding side of the patient s face. A headgear unit having a pair of temple elements and a front housing rotatably attached to the temple elements where the front housing includes at least two cameras and a 3D compass all movable within the front housing is then positioned on a patient s head. Each of the two cameras is adjusted such that its view field picks up one of the two anthropological baselines on the patient s face. These view fields of the two cameras are then used to construct a Human Skull Base Plane as a plane formed by the left and right anthropological baselines when these anthropological baselines are parallel and aligned. The 3D compass is then positioned into a measuring plane coinciding with the Human Skull Base Plane and is used to quantitatively measure a three dimensional orientation of the patient s head at the time when the 3D compass is positioned within the measuring plane coinciding with the constructed Human Skull Base Plane.
