A face-bow is a metal measuring caliper that precisely records the three-dimensional spatial position of the patient’s upper jaw and teeth relative to the basal bones of the skull and, specifically, to the axis of rotation (hinge axis) of the temporomandibular joint. This recording is then transferred to an artificial jaw simulator (articulator) in the laboratory. If face-bow transfer is not performed during the laboratory phase, the technician sees the patient’s jaw closure as a purely “hypothetical/average” straight line on the computer or articulator. In this case, even if the bridges or crowns produced do not sit high statically (when the patient simply closes their mouth), when the patient moves their jaw from side to side to chew (during dynamic movements), the teeth will collide, catch, and premature contacts (articulation errors) will occur; this can lead to the porcelain chipping or acute trauma to the temporomandibular joint.
