RESUMO
The purpose of this study was to analyse the skeletal changes and stability of the distracted segments during and after simultaneous widening and bilateral lengthening of the mandible in baboons with a miniaturized intraoral bone-borne osteodistractor. Distraction appliances were activated 5 days after vertical posterior body and midsymphyseal osteotomies at a rate of 0.9 mm/day for 10 days. The appliances were then stabilized for a period of 8 weeks, after which the animals were killed. The distraction gaps and gingival tissues were studied clinically and on standardized radiographs. The proportional movement of the distracted segments that we found supports the clinical use of the miniaturized intraoral bone-borne distraction appliance to widen and lengthen the mandible selectively. It also supports the concept of positioning the mandibular osteodistractors parallel to the common vector of distraction, which should parallel the corrected maxillary occlusal plane.
Assuntos
Mandíbula/cirurgia , Procedimentos Cirúrgicos Bucais/métodos , Osteogênese por Distração , Animais , Fenômenos Biomecânicos , Cefalometria , Modelos Animais , Osteogênese por Distração/instrumentação , Osteogênese por Distração/métodos , Osteotomia/métodos , Papio , RotaçãoRESUMO
During recent years, distraction osteogenesis has gained in popularity for the treatment of various bone deficiencies either in the vertical, transverse, or anteroposterior dimension. Distraction osteogenesis has been shown to be an effective technique for mandibular widening and lengthening where traditional orthognathic surgery has important limitations. The intraoral approach to these procedures prevents damage to the inferior alveolar nerve and the developing dental follicles, and eliminates hypertrophic facial scars. Intraoral distraction osteogenesis also avoids donor-site morbidity, and minimizes the need for blood transfusion or prolonged fixation. This intraoral application provides for enhanced patient acceptance and reduces the potentially negative psychosocial effects of wearing an extraoral distraction appliance.
Assuntos
Mandíbula/cirurgia , Avanço Mandibular/métodos , Osteogênese por Distração/métodos , Protocolos Clínicos , Humanos , Fixadores Internos , Osteogênese por Distração/instrumentação , Planejamento de Assistência ao PacienteAssuntos
Mandíbula/cirurgia , Maxila/cirurgia , Procedimentos Cirúrgicos Bucais/métodos , Osteogênese por Distração/métodos , Análise do Estresse Dentário , Fixadores Externos , Assimetria Facial/cirurgia , Feminino , Humanos , Má Oclusão/cirurgia , Mandíbula/anormalidades , Avanço Mandibular/métodos , Micrognatismo/cirurgia , Procedimentos Cirúrgicos Bucais/instrumentação , Osteogênese por Distração/instrumentação , Técnica de Expansão Palatina , Palato Duro/cirurgia , Estresse Mecânico , Zigoma/cirurgiaRESUMO
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 surgical technique has been developed to widen the mandible. The method is based upon gradual osteodistraction following vertical interdental symphyseal osteotomy. Ten patients with transverse mandibular deficiency and significant dental crowding were treated by symphyseal distraction and subsequent non-extraction decompensating orthodontic treatment. Either an intraoral tooth-borne Hyrax appliance or a new custom-made bone-borne osteodistractor was used to gradually widen the mandible. The surgical procedures were accomplished under local anaesthesia and intravenous sedation in an ambulatory surgical setting using an individualized distraction protocol. The appliances were activated 7 days after symphyseal osteotomies, once each day at a rate of 1 mm per day and stabilized for 30-40 days after distraction. After the segments were distracted, non-extraction orthodontic alignment of the mandibular anterior teeth was accomplished. The symphyseal distraction gaps were bridged by new bony regenerate. Distraction osteogenesis provided an efficient surgical alternative to orthognathic surgery for widening the mandible and treatment of transverse mandibular deficiency without extraction of teeth.