Original Research Article DOI: 10.18231/2455-6785.2017.0028 The role of orthodontist in distraction osteogenesis Vedavathi H.K.1, Chirag Arora2,*, Bharath Reddy3, Sowmya K.S.4, Goutham N5 1,3,4,5Reader, 2PG Student, Dept. of Orthodontics, V.S. Dental College & Hospital, Bengaluru, Karnataka *Corresponding Author: Email: [email protected] Abstract Although orthognathic surgery has gained recognition over the last few decades it still has not overcome several limitations like acute advancement of bone segments and adaptation of soft tissue relative to the new position. With the advent of distraction osteogenesis these limitations have been omitted. Recently, several experimental and clinical investigations have established that controlled progressive mechanical traction of bone segments at an osteotomy site created in the craniofacial region can form new bone parallel to the direction of traction. Thorough planning, careful evaluation and communication between the orthodontist and maxillofacial surgeon is the key to a successful outcome of the treatment and resolution of malocclusion. In addition, management of dentition prior to distraction need careful assessment for better finish of occlusion after distraction osteogenesis has been performed. Hence, the purpose of this article is to review the historic development and biologic foundation of mandibular distraction osteogenesis, and role of orthodontist in distraction osteogenesis. Keyword: Distraction osteogenesis, Soft tissue capsule, Neuromuscular Introduction distraction. By applying distraction forces sequence of Facial asymmetry, mandibular hypoplasia, and adaptive changes surrounding periosteal matrix is congenital malformation of jaws are common propagated, termed as distraction histogenesis. Due to abnormalities of the craniofacial complex. the influence of tensional stresses generated by gradual Traditionally, skeletal deformities have been corrected distraction, active histogenesis occurs in surrounding via functional orthopedics in growing patients or tissues. These adaptive changes may permit larger orthognathic surgery with skeleton fixation in non- skeletal movements while diminishing the potential growing patients.(1-4) Adaptation and stability of the relapse seen in acute orthopedic corrections. adjacent muscles and soft tissues are one of the Distraction process includes following fundamental limitations and controversies related to orthognathic sequential phases in which different biologic surgery and functional orthopedics.(2,4,5) Many phenomenon are induced. congenial deformities require large amount of skeletal 1. Osteotomy cut movements which is perhaps not possible with 2. Latency period orthognathic surgery may lead to compromise in 3. Distraction phase function and esthetics.(6-7) One of the major demerits of 4. Consolidation phase orthognathic surgery is that it permits only acute The distraction technique presents wide changes in the spatial arrangement of skeleton rather possibilities of use in some areas of dentistry, i.e. than provide de novo bone formation and which surgical orthodontics, facial orthopedics and in oral requires the needs of bone graft. It does not permit the rehabilitation where one of the major problems is the change in shape and size of the bones to maximize the alveolar bone loss for the support for prosthesis, structural integrity, functional balance and esthetic of implantation and adjacent soft tissues. Recent clinical the patient. reports have acknowledged the successful application Taking into account of these limitations, recent of osteodistraction in treating skeletal deformities of the approaches have been directing at new bone growth craniofacial region.(16-33) The use of gradual incremental which is called as “distraction osteogenesis”. traction of the mandible has allowed up to 20 mm of Distraction Osteogenesis is defined as the creation of de lengthening with no associated pain. Because these novo bone and adjacent soft tissue after the gradual and conditions are typically treated by a team approach, a controlled displacement of a bone fragment obtained by thorough understanding of the evolution and future surgical osteotomy. Periosteal matrix adjacent to development of osteodistraction is of paramount skeletal tissue have been noted to form under stress, importance to the orthodontist. which includes mucosa, skin, tendon, muscle, blood vessel, cartilage and peripheral nerves.(8-15) Steady bone History remodeling, in varied directions without surgical The progression of craniofacial distraction interventions is now possible by utilization of osteogenesis was based on the development and distraction osteogenesis. The traction by the distractor refinement of dentofacial traction, craniofacial appliance institutes tension within the callus which osteotomies, and skeletal fixation methods. Later, stimulates new bone formation parallel to the vector of modifications of these techniques were merged into Indian Journal of Orthodontics and Dentofacial Research, July-September 2017;3(3):141-147 141 Vedavathi H.K. et al. The role of orthodontist in distraction osteogenesis osteodistraction procedures that were finally application of Illizarov’s principle to the mandible standardized based on experiences with distraction appeared in 1973 by Snyder et al. osteogenesis on long bones. External fixation device for mandibular The application of tensile and compressive forces lengthening was first applied given by McCarthy in to bones of the craniofacial skeleton in the field of 1989. Illizarov (1990) showed that the fibrous matrix in orthodontics and dentofacial orthopedics is not a new the tensioned area was capable of differentiating by concept. Since eighteenth century principles of dental itself into lamellar bone tissue. He entitled the so called traction for the correction of skeletal deficiencies have “Illizarov effect”. A comprehensive analysis of been popular in dentistry. In 1728, Pierre Fauchard distraction regeneration at different stages of formation illustrated the use of the expansion arch. When the was given by Karp and co-workers based on metal plate was ligated to the crowded dentition, the experimental studies in 1990. teeth were widened to a normal form. However, the McCarthy et al (1992)(40) was the first author to limitation of this form of traction was that only tooth relate distraction osteogenesis application in human. movement arose with little effect on the skeletal tissue. Querido and Fan were among the first authors to use an In 1859, Wescott was the first who reported the intra-buccal distraction in human for orthopedic implementation of mechanical forces on the bones of corrections. the maxilla. He used two double clasps separated by a telescopic bar to correct a crossbite in a 15-year-old Indications of Mandibular Distraction girl. However, the demerits of this procedure were that Osteogensis(41-43) it was slow and tedious andprolonged treatment 1. Severe mandibular retrognathia/micrognathia duration. Later on, Angell performed a similar 2. Craniofacial syndromes: hemifacial microsomia, procedure with a differentially threaded jackscrew Treacher Collins syndrome, Nager syndrome, connected to the premolars. Palatal expansion was Pierre Robin sequence achieved through the separation of the maxillary bones 3. Severe mandibular asymmetry at the midpalatal suture in 2 weeks. A new protocol for 4. Post-traumatic deficient mandibular growth and palatal expansion was further standardized by Goddard temporomandibular joint ankylosis in 1893. He activated the device twice a day for 3 5. Revision mandibular orthognathic surgery weeks followed by a stabilization period to allow the 6. Mandibular retrognathia with temporomandibular deposition of “osseous material” in the created gap. joint disease or juvenile rheumatoid arthritis In 1905, Alessandro Codivilla(34) introduced 7. Mandibular retrognathia with obstructive sleep surgical techniques for lengthening of the lower apnea extremities. In 1934, the New York hospital for joint 8. Mandibular defects from tumor resection disease worked on an early method developed by Illizarov. The US team of surgeons came up with the Advantages of Distraction Osteogensis(40,44-49) concept of metal frame to hold the limb in placed until 1. Allows greater mandibular lengthening of 10–30 the healing was complete. Major amelioration came mm with a technique introduced by Russian orthopedic 2. Can be applied to unusual bony and soft tissue surgeon Gavril Illizarov. He developed procedure anatomy which induced new bone formation and regeneration of 3. Allows slow gradual soft tissue adaptation to surrounding soft tissues under the tension.(35-36) extreme mandibular lengthening According to Wassmund in 1927,(37) intraoral tooth 4. Minimal to no skeletal relapse after extreme borne appliances for first mandibular distraction mandibular lengthening osteogenesis which was gradually activated over a 5. Can be applied to neonates, infants, and pediatric period of 1 month which was carried out by Rosenthal. patients with obstructive sleep apnea In 1937, Kazanjian(38) implemented a new protocol for 6. Less invasive surgery compared with bone-grafting mandibular osteodistraction by using gradual procedures incremental fraction. After L-Shaped osteotomies in 7. Avoids intermaxillary fixation corpus he attached a wire hook to the symphysis, 8. Avoids bone grafting and potential donor-site thereby providing direct skeletal fixation. morbidity In 1948, even though Crawford(39) followed