This fact is from Jaw Relations & Facebow in Prosthodontics. It is a commonly tested concept in NEET MDS examinations. Understanding this fact is crucial for answering MCQs correctly.
VDO minus VDR equals Freeway space 2-4mm
Facebow transfers hinge axis
Arbitrary facebow most common
Kinematic facebow = true hinge axis
Frankfort plane = horizontal reference
Camper line = ala-tragus line = occlusal plane.