point of centricity

If the point of the buccal cusp of the lower right molar, put in lateral position, arcs around the upright axis of the right condyle, it will reach a station where further muscular efforts leftward will change the cusp’s direction so that it will arc around the left condyle. The station where the right arc ends and the left arc begins is a point of mandibular centricity. While the right cusp point orbits (arcs) around the near vertical axis, all other points in the jaw join in orbiting (arcing). The left condyle arcs rearward until it reaches a cranial backstop; then the muscles start rotating it and carrying it leftward, and the right condyle begins arcing forward, downward, and medially. In the right and left swings of the jaw, a condyle reciprocally alternates between being a rotator and an orbiter. The point of centricity of the mandible is demonstrated usually on a horizontal plane, but it can be demonstrated on all three planes of projection. The point of centricity is rearmost, midmost (between the arcs of motion), and uppermost. See also face-bow and relation, centric.