Hybrid appliances: a component approach to dentofacial orthopedics

The net treatment effect of or orthodontic or orthopedic therapy may be considered as the algebraic sum of all dentoalveolar, skeletal, and neuromuscular changes over time. Cumulative effects resulting from growth and adaptation in response to therapeutic biomechanical interference may be manipulated to result in clinically significant morphologic alterations in the growing child's dentition and craniofacial skeleton. All of the currently used functional appliances can be regarded as assemblies of a small number of component parts. This article attempts to identify these salient components and their respective contributions to the total design and probable function of such appliances. The logical consequence of such an analysis is the derivation of principles upon which the design of "hybrid" appliances may be based. Hybrid appliances are specifically and individually tailored to exploit the natural processes of growth and development. Such an approach represents a departure from the practice of adopting a "named" appliance for the treatment of a class of malocclusion. Instead, a detailed analysis of skeletodental and soft-tissue features, together with the patient's growth status and underlying cause of the malocclusion, are used to establish a set of treatment objectives. This in turn determines the selection of the components and their assemblies, resulting in appliance designs that uniquely match the needs of individual patients.