CONTROLLED MULTIPLANAR DISTRACTION OF THE MANDIBLE - DEVICE DEVELOPMENT AND CLINICAL-APPLICATION

Distraction osteogenesis has been shown to be an effective method of l engthening and augmenting endochondral bone. It has also been applied effectively in the reconstruction of the membranous bones of the crani ofacial skeleton. With the accumulation of clinical experience in mand ibular distraction, the differences between endochondral and membranou s bone distraction have become apparent, especially in the limitations of uniplanar distraction for the three-dimensional reconstruction of the deficient mandible. Distraction of the mandible in a single plane cannot satisfy fully the functional and structural requirements of the patient with malocclusion as well as deficiency of the skeletal and s oft tissue. This study reports the development and clinical use of a m ultiplanar mandibular distraction device with the ability to achieve l inear distraction (Z-plane or sagittal), angular distraction (Y-plane or vertical), and transverse distraction (X-plane or coronal). The dev ice contains two independent gear arrangements attached to two arms th at extend from the central unit. Therefore, the trajectory of the rege nerated bone may be changed during the distraction process. The device also allows manipulation of the various planes of movement independen t of each other. Furthermore, the rotational points for the multiplana r distraction devices are located at a single point; therefore only a single osteotomy and two pin sites are required. The multiplanar distr action device allows the surgeon to customize and contour the dimensio ns of the distraction process by controlling the trajectory of the tra nslation of the regenerated bone.