Kinematic facebow or Hinge axis facebow A facebow with adjustable caliper ends used to locate the transverse horizontal axis of the mandible (GPT8)It locates the true (exact) centre of condylar rotation or transverse horizontal axis. It is preferred in full mouth reconstructions. Hinge axis face-bow records—relationship of teeth to the axis of rotation of the jaw. It usually requires a fully adjustable articulator. When we consider the rotation of any circular object, only the central point rotates, any other point within the circle will show translatory movement. Similarly in the condyle, the centre alone will display pure rotation. This principle used to determine the true centre of rotation using kinematic facebow. • The condylar rods are first positioned arbitrarily similar to facia type of facebow at a point 13 mm anterior to the auditory meatus on the canthotragal line. The patient is instructed to make opening and closing movements in CR. The opening should not be greater than 12 mm as then the condyle will then begin to translate instead of rotating. The position of the condylar rod is shifted around the arbitrary mark until it shows pure rotation. This is the centre of condylar rotation. This point is marked, the condylar rods are locked, the facebow assembly is removed and mounted on an appropriate articulator.Key Concept:Hinge axis face-bow records—relationship of teeth to the axis of rotation of the jaw. Face-bow measures relationship of maxilla to Opening and closing axis.Ref: Textbook of prosthodontics V Rangarajan Ed. 2nd