Abstract: A mechanically operated, cable driven jack includes a base, a hollow upright support member secured to the base, a first hollow support tube telescopically received in the support member, and a second hollow support tube telescopically received within the first support tube. The first and second support tubes are interconnected by means of a cable and a series of sheaves and driven by a winch employing a worm gear drive principle so as to move the first and second support tubes from collapsed condition to an extended position. Safety means are also provided to limit the downward movement of the tubes and the arrangement of the pulley sheaves and the cable drive is such that upward movement is also controlled. Modifications of the jack include the provision of selected alternate attachment points for the free end of the cable so as to enable the jack to be modified for fast or slow movement, depending upon the precise engagement point of the free end of the cable.

Abstract: A support post of each alveolar retractor, which is adjustably supported in a clamp means terminating each opposite end of a transverse inferior bar of a surgical mouth gag for both axial rotational and sliding movement, has a superior arcuate bar which at its medial end terminates in an upper jaw engaging member and is mounted in the upper end of said post for lateral-medial sliding adjustment to provide increased surgical exposure. Several modifications of the superior arcuate bar provide pivoting of the upper jaw engaging member to insure an optimum fit. Additional modifications of the transverse inferior bar provide mandibular engaging members which coact with the upper jaw engaging members to mount the mouth gag in operative position independently of the tongue retractor, the latter being removably mountable from the front of the transverse inferior bar without disturbing the position of the mouth gag.