Described is a mandibular manipulator instrument as a standalone tool or with associated mouthpiece that includes two interlocking laterally sliding frames including a movable upper and a lower incisor pull, shaped for receiving a patient's central incisor teeth and a pair of pinion shafts for driving the upper and lower incisor pulls. A screw thread is used to provide a precise lateral motion for the sagittal measurement. The mouthpiece is constructed of resilient rubber. The manipulator is positioned and held in the resilient rubber mouthpiece by the two pinions protruding through acoustically tight apertures respective to each pinion's position. The manipulator can be used for other applications in an embodiment without the mouthpiece and/or in combination with a bite registration shape that is part of the manipulator frame.