Tratamiento ortodóncico-quirúrgico de la deficiencia mandibular transversal por distracción osteogénica

Transverse mandibular deficiency with crowding of the mandibular anterior teeth is frequently present in patients with class I and II malocclusions. The hallmarks of treatment by compensating orthodontics, functional appliances or orthopaedic devices are instability, compromised periodontium and compromised facial aesthetics. A new intraoral surgical technique has been developed to widen the mandible. The method is based upon gradual osteodistraction following vertical interdental symphyseal oateotomy. Two hundred and fifty-five patients with transverse mandibular deficiency and significant dental crowding were treated by symphyseal distraction and subsequent non-extraction decompensating orthodontic treatment. Either a tooth-borne Hyrax or a Dynaform appliance, bone-borne or hybrid dental-bone-borne distractor was used to gradually widen the mandible. The surgical procedures were accomplished under local anesthesia and intravenous sedation in an ambulatory surgical setting using an individualized distraction protocol. The appliances were activated 7 days after symphyseal osteotomies, at a rate of 1 mm per day and stabilized for 30-60-90 days after distraction. After the segments were distracted, non-extraction orthodontic alignment of the mandibular anterior teeth was accomplished. All the symphyseal distraction areas were bridged by new bony regenerate after consolidation, the new mandibular perimeter allowed the new dental alignment without relapse following a long-term follow up of from 2 to 15 years. Distraction osteogenesis provides an efficient surgical alternative to orthognathic surgery for widening the mandible and treatment of transverse mandibular deficiency without dental extractions.