Abstract: An extraoral anchorage device for imparting orthopedic force to teeth is provided which comprises outer bows for transmitting an external force to teeth and inner bows for transmitting the force delivered by the outer bows to buccal tubes respectively fixed to said teeth, said inner bows being connected to the outer bows and having outer free ends. In the extraoral anchorage device the improvement consists in that the outer free ends of said inner bows have a non-circular cross section. By the use of the extraoral anchorage device according to the present invention, the orthopedic force is transmitted from the outer free ends of the inner bows to the buccal tubes without rotational movement.

Abstract: A metal bracket for use in orthodontic treatment is provided which comprises a bracket body for receiving and securing a wire which transmits orthodontic force to the tooth and a support base for supporting said bracket body. A plurality of fine pores in the form of undercut is formed by subjecting the base to sand-blasting treatment and then to etching process. Such metal brackets have strong adhesion to the teeth.