Mandibular Reconstruction Using Extraoral Trifocal Bone Transport: Report of a Case Using a New Device

Abstract

A newly designed mandibular stabilization and transport distraction system is an extraoral assembly of a half-elliptical rod, with movable clamp attachments that serves the dual purpose of stabilization and transport distraction osteogenesis of mandibular segmental defects. The rod is threaded and made of stainless steel, and it conforms to the shape of the human mandible. Mandibular stabilization and bone transport are accomplished with the help of different assemblies that are attached onto this rod. There are 3 different assemblies having separate functions but achieving the same goals of mandibular stabilization and bone transport. All the assemblies have a common base unit that moves on threads of the curved rod in a graduated manner, controlled by a spanner. One full turn of 360° moves the assembly by a distance of 1 mm. The first assembly is the stabilization assembly, which helps in the rigid fixation of the frame to the mandible by use of at least 2 clamp units on either side of the midline. It helps in stabilization of the mandibular segments in an anatomic position. The bone transport assembly consists of 1 or 2 moveable clamp assemblies that are fixed at 1 end to the transport disc of the mandible, while the base unit assembly glides and engages on the threads of the distraction rod. This allows bone regeneration and laying down of new bone in the natural position along the path of movement of the transport disc in a curvilinear manner. This system allows mandibular regenera-