Distraction Osteogenesis of the Maxillofacial Skeleton: Clinical and Radiological Evaluation
Kitapta bölümler > Diğer · 2011
Yazarlar: Mehmet Cemal
CT Scanning - Techniques and Applications, Diğer, Uluslararası, 2011, ,
DOI: 10.5772/22721
Özet
Traditional treatment modalities for BMDTraditional treatment options include compensating orthodontics, functional appliances, and orthopedic devices.Arch wire expansion, Schwarz plates, and proclination can all produce alveolar expansion.When these patients are treated using classical orthodontic appliances, the duration of the treatments increase and risks such as root resorption, undesired movements of anchorage teeth, and relapse occur.These therapies show relatively stable results for younger patients, particularly those who presented with lingually tipped teeth that need to be decompensated (Mommaerts, 1999;Neyt et al., 2002).Orthognathic surgery techniques for the treatment of BMD are used for many years.However, in these methods, mucosa can not adopt to rapid movement of bone fragmants after the osteotomies.Therefore, in the postoperative period, relapse, functional and esthetic www.intechopen.comCT Scanning -Techniques and Applications 122 problems ocur (Guerrero et al., 1997;Little & Riedel, 1989;Mommaerts & Vande Vannet, 2004).Distraction osteogenesis technique (DO) offers a solution for these problems. Distraction osteogenesisDistraction osteogenesis, also called callus distraction, callotasis, osteodistraction and distraction histogenesis is a surgical process used to reconstruct skeletal deformities and lengthen the long bones of the body (Ilizarov, 1989a(Ilizarov, , 1989b)).The human body possesses an enormous regenerative capacity.DO takes advantage of this regenerative potential to induce the regeneration and remodeling of bone, cartilage, nerve, muscle, blood vessels, and skin.DO is defined as the creation of neoformed bone and adjacent soft tissue after the gradual and controlled displacement of a bone fragment obtained by surgical osteotomy.With this procedure, bone volume can be increased by gradual traction of a fracture callus formed between osteotomized bony segments.When the desired or possible length is reached, a consolidation phase follows in which the bone is allowed to keep healing.DO has the benefit of simultaneously increasing bone length and the volume of surrounding soft tissues.Clinically, this offers a distinct advantage because several craniofacial anomalies have soft tissue hypoplasia in addition to deficient bony structures.Neurovascular elements contained within distracted bony segments are also stimulated to regenerate.Experimental studies in dogs demonstrate regeneration of the mandibular canal containing both neural and vascular elements.However, the functional level of the regenerated neurovascular structures is less than normal (Imola et al., 2002;Imola et al., 2008). History of DO techniqueHowever, bone distraction is not a new concept, DO of the craniofacial skeleton has become increasingly popular as an alternative to many conventional orthognathic surgical procedures.For patients with mild to severe abnormalities of the craniofacial skeleton, distraction techniques have increased the number of treatment alternatives.DO initially used in orthopedic surgery by Codivilla in 1905.Abbott (1927) contributed in the improvement of Codivilla method by incorporating pins instead of casts used by Codivilla.Allan (1948) was the first to incorporate a screw device to control the rate of distraction.Research into osteogenic distraction originated in the fields of orthopedics and traumatology.However, the complication rate remained high and the technique was not understood until Gavriel Ilizarov, a Russian orthopedic surgeon, performed detailed studies in 1952.Ilizarov found that succesful distraction depends of the stability of fixation, the rate of daily distraction, and the preservation of the local soft tissue envelope and vascular supply.Mandibular lengthening by gradual distraction was reported in 1973 by Synder et al. who used an extraoral device in a canine study; new bone formation at the elongated site was demonstrated later by Karp et al. (1990).The first clinical results of craniofacial DO were reported in 1992 by McCarthy et al. in a small series of patients with congenital mandible deformities.Authors successfully elongated the mandible by up to 24 mm.Interest in craniofacial distraction was slow to grow initially, with sporadic experimental reports appearing throughout the ensuing 2 decades.However, in the early 1990s, experimental investigation intensified following reports that examined lengthening canine mandibles and the use of DO to successfully close canine segmental lower jaw defects.Thereafter, several studies demonstrated the ability to apply DO at several different sites, www.intechopen.com