Distraction osteogenesis in craniofacial surgery: a review.

Distraction osteogenesis is a technique of new bone formation by the gradual separation of bony fragments. The method, although initially developed for limb lengthening, is now being applied in the treatment of craniofacial deformities. A number of principles have been established through careful scientific study to guide clinical practice, such as the ideal rate and rhythm of distraction, the need for periosteal preservation during bone division, a "latent period" of neutral fixation before, and a "consolidation period" after distraction. The technique is being applied in craniofacial surgery particularly for mandibular deformities and offers considerable advantages over previous methods such as osteotomy and inlay bone grafting. Donor site morbidity is avoided, the investing soft tissue envelope is concurrently expanded, and the magnitude of the procedure is less. However, the technique is still in its infancy and requires further modification and refinement before widespread acceptance as a treatment in mainstream craniofacial surgery. Problems with cutaneous scarring and socially undesirable external hardware, particularly in the pediatric population, have led to the emergence of intraoral miniature devices, with the ultimate goal of development of a multiplanar internal autodistractor. Furthermore, many principles well established in leg lengthening, such as the rate and rhythm of distraction, need to be reexamined and the parameters redefined with particular reference to the craniofacial skeleton. Distraction osteogenesis has an expanding role in craniofacial surgery.