Patent ID: 8632477

Claim:
A lower jaw position determining system for determining a normal lower jaw position of an examinee, comprising: a computer; a head movement measuring section for measuring movement of the head using a sensor configured to be fixed to a head of the examinee; a center calculating section for obtaining measurement data based on the movement of the head measured by the head movement measuring section, and calculating, using the computer, an approximate center of movement resulting from approximating the movement of the head as rotational movement of a rigid body; a lower jaw path measuring section for measuring a plurality of paths of masticatory movement of the lower jaw using a sensor configured to be attached to the lower jaw of the examinee, for a plurality of lower jaw positions of the examinee; and a position determining section for (i) approximating, using the computer, the masticatory movement of the lower jaw as rotational movement of a rigid body to find one of the plurality of measured paths of the lower jaw whose center of movement in the approximation matches the calculated approximate center of movement of the head, (ii) determining, using the computer, an approximate lower jaw position that corresponds to the found path of the lower jaw, and (iii) outputting the determined approximate lower jaw position as a normal lower jaw position for the examinee.