Apparatus for tracing centric relation of mandible

A mounting reference die for a tracing plate included in a Gothic arch tracing apparatus comprising:

• a die plate;
• a pin hole formed through said die plate and adapted to receive a tip of a stylus included in said tracing apparatus;
• a plurality of longitudinally spaced lateral horizontal lines formed on an upper surface of said die plate and adapted to measure a lateral inclination of said tracing plate with respect to an occlusal plane;
• a plurality of parabolic horizontal lines formed on said upper surface of said die plate to have parabolic shapes of different sizes conforming to those of different patients' dentitions defined on said occlusal plane, respectively, each of said parabolic horizontal lines being laterally symmetric with respect to the center thereof;
• a front depth measuring bar downwardly protruded from a lower surface of said die plate and arranged at a front portion of said die plate on a center line extending through the centers of said lateral horizontal lines while being orthogonal to said lateral horizontal lines;
• a rear depth measuring bar serving as a vertical adjustment bar and being upwardly protruded from said upper surface of said die plate in rear of said front depth measuring bar, said rear depth measuring bar serving to measure a depth of a maxilla in cooperation with said front depth measuring bar;
• a plurality of lateral depth measuring holes formed through said die plate at opposite ends of said parabolic horizontal lines in such a fashion that they are laterally symmetric with respect to said center line;
• a pair of lateral depth measuring bars fitted in two laterally symmetric ones of said lateral depth measuring holes selected in accordance with the size of said maxilla, said lateral depth measuring bars serving to measure a depth of said maxilla at opposite lateral ends of said oral cavity, respectively;
• a bolt hole formed through a central portion of said die plate;
• and
• a guide bolt vertically inserted into said bolt hole and adapted to establish an accurate lateral horizontal relation of said tracing plate with respect to said maxilla, said guide bolt including a clamp bolt inserted into said bolt hole, a pair of clamp nuts threadedly coupled to said clamp bolt at opposite sides of said die plate, respectively, to clamp said die plate in a state perpendicular to said clamp bolt, and a horizontal guide surface formed at a head portion of said clamp bolt and adapted to maintain said tracing plate in parallel to said die plate.