Devices & Techniques

In general, two types of mandibular distraction appliances have been used - extraoral and intraoral. The extraoral appliances are attached to the mandible by percutaneous pins connected externally to fixation clamps. The fixation clamps, in turn, are joined together by a linear distraction bar (distractor) such that when activated, the bar effectively pushes the clamps and the attached bone segments apart, generating new bone in its path. Relative to the direction of lengthening, the extraoral devices can be divided into uni-directional, bi-directional, and multi-directional devices. The intraoral appliances are entirely contained within the oral cavity. They are attached to the bone (bone-borne), to the teeth (tooth-borne), or simultaneously to the teeth and bone (hybrid). A linear distractor, similar to an orthodontic expansion device, is used despite the method of intraoral attachment (Samchukov et al., 1998c).

FIG. 3.1. Classification of mandibular distraction appliances.

Audio