Mandibular Lengthening: Frankfurt System
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Cornelius M. Klein, MD, DMD, PhD

Introduction

The treatment of craniofacial malformations is always a challenge. Although in mild cases orthodontic treatment alone may benefit the patient, surgical intervention is mandatory in cases of moderate to severe three-dimensional craniofacial defects and deformities. Moreover, because the malformation becomes more severe as patient age increases, the surgery should be performed as early as possible.

Since 1991, we began to develop a miniturized elongation device that would be useful for correcting multi-dimensional deformities of the facial skeleton, possibly avoiding the problems associated with graft-dependent reconstructions in small children. Our concern from the beginning was that a uni-directional device would allow bone lengthening in only one plane and would not be sufficient for optimal reconstruction of the mandible. It is known that in most cases lower jaw hypoplasia predominantly affects the ascending ramus. For successful lengthening of the ramus, a uni-directional device must be positioned as vertical as possible. In cases with severe mandibular hypoplasia, however, the anatomy of the ramus is so compromized that vertical positioning of the uni-directional distraction appliance is often impossible. In addition, the position of uni-directional appliances cannot be adjusted during lengthening.