Mandibular Distraction Osteogenesis

Mandibular hypoplasia is a common dentofacial deformity requiring a combination of orthodontic and surgical treatment. Before the introduction of distraction osteogenesis various orthognathic surgical procedures were carried out to treat mandibular hypoplasia. Orthognathic procedures like corpus lengthening by bilateral sagittal split ramus osteotomy and genioplasty are commonly practised all over the world to address the high esthetic demands and functional problems. But hardly there are any established orthognathic surgical procedures to address the deficiency of the posterior part of the mandible that is ramus and condyle.Transverse mandibular deficiency is one of the most difficult problems to be addressed surgically. With the advent of distraction osteogenesis there is a change in concept of addressing mandibular deficiency. Mandibular corpus distraction was first performed by McCarthy et al using an extraoral unidirectional distraction device. The precision of bone lengthening with extraoral distracters did not accurately match the device settings. Since then due to sustained research and design and collaboration with the manufacturers, clinicians have developed various devices to improve the results of mandibular lengthening. Distractor devices of various shape and size are developed for intraoral use in specific anatomical locations of mandible. This presentation will focus on use of intraoral distraction devices on different anatomical locations of mandible. The surgical methods of corpus, ramus, ramuscondylar unit, and symphyseal distraction osteogenesis and associated complications will be discussed in detail.