PURPOSE: To facilitate the attaching/detaching operation executed by a patient himself by fixing a hook-like pin to a trued molar or a band to be put thereon, and providing a socket part in which a minute shaft hole for inserting the hook-like pin is pierced on the inner end of an inner bow.

CONSTITUTION: An inner bow 10 has a center part 11 formed by curving an elastic thin wire in a shape running along a tooth train bow, and a socket part 14 provided on two inner ends 12. As for the socket part 14, on the end part 16 of a cylindrical part of a thin cylindrical shape or a conical shape of gentle inclination. a minute shaft hole 15 is pierced into certain depth in the major axis direction. An insert pin member 20 has a hook-like pin 22 provided projectingly in the direction running along an external outline of the tooth train bow from a base 21, and a base part 23 of the hook is fixed to the base 21. The base 21 of the insert pin member 20 is fixed to a band 24 to be put on a true molar by adhesion, etc. A detachable connecting means 35 consisting of a projecting part 36 formed in a projecting shaped on the outside surface of the center part 11 of the inner bow 10, and an opening part 37 pierced in the center part 31 of a face bow 30 can connect easily the face bow to the inner bow.