Bone-Screw Anchorage for Pendulum Appliances and Other Fixed Mechanics Applications

The pendulum appliance has proven to be an effective therapeutic choice for moving maxillary molars distally, but anchorage problems are associated with its use: (1) flaring of the anterior teeth, (2) difficulty maintaining the distal position of the molars, and (3) tendency to “round-trip” the molars when buccal segments are retracted. Headgears, as well as Nance appliances, have been used as supplemental anchorage after molars are retracted, however, all conventional methods are problematic in effectively controlling molar anchorage when the anterior teeth are retracted. Osseointegrated palatal implants are effective supplemental anchorage, but are relatively expensive procedures with multiple time-consuming steps. The present report demonstrates that nonintegrated, infrazygomatic bone screws are adequate anchorage devices for pendulum appliances. The treatment of a challenging malocclusion is presented to demonstrate the utility of the proposed method. It is concluded that there is a promising future for pendulum appliances, supplemented with bone screw anchorage. Additional clinical applications for bone screw anchorage are demonstrated for noncompliant correction of intermaxillary molar relationships.