Extraoral appliances: A twenty-first century update.

With the locations of the centers of resistance of the dentomaxillary complex having recently been defined, and with the newly acquired knowledge of the critical interplay between part-time extraoral and full-time intraoral force systems, the basic designs of all types of extraoral appliances are discussed in depth. Armed with this information, the clinician can improve the efficiency of all extraoral appliances to obtain better dentomaxillary-complex growth control and negate or enhance appliance-induced intraoral force systems.