1. DISTRACTION OSTEOGENESIS FOR RECONSTRUCTION OF MAXILLARY DEFECTS Mancha de la Plata, M; Martos Díez, PL; Muñoz Guerra, M; Naval Gías, L; Cho Lee, GY; Rosón, S; Escorial Hernández, V; Sastre Pérez, J; Rodríguez Campo; FJ; Rubio Bueno, P; Díaz González, FJ. Department of Oral and Maxillofacial Surgery. University Hospital La Princesa. Madrid. Spain. INTRODUCTION: Distraction osteogenesis has been widely used for reconstruction of segmental bone defects. Bone transport is a modality of distraction osteogenesis were a vascularized bone disc is moved slowly across the defect inducing new bone formation. The advantages of applying the distraction technique for reconstruction of maxillary defects after ablative surgery for oral malignancies is its lack of donor site morbidity and its ability to increase the overlying soft tissue histiogenesis. CONCLUSION: Bone transport is a reliable method for maxillary reconstruction. Using this method, more aggressive procedures can be avoided. The bone obtained after distraction is suitable for placement of osseointegrated implants. PATIENTS AND METHODS: We report three patients, with ages of 38, 54 and 72 years old, who underwent bifocal distraction osteogenesis for reconstruction of maxillary defects. In two cases with diagnosis of suamous cell carcinoma and carcinoma de células gigantes bone transport was used as primary reconstruction after ablative surgery. The third patient with a maxillary osteosarcoma underwent bone transport for secondary reconstruction. At the beginning of distraction, maxillar segmental defects ranged from 22 to 53 mm. In patients 1 and 2 the premaxilla region was included in the reconstruction. Patient 1 received adjuvant radiotherapy. Distraction was performed by unidirectional semi-buried devices at a rate of 0.5 mm per day, after a latency period of 10 days. Panoramic radiographs were taken monthly during the distraction and consolidation periods to monitor the progress of the distraction. Patient 1 Patient 2 Patient 3 Sex/age M/38 M/72 F/54 Main maxillar maxillar giant maxillar Diagnosis osteosarcoma cell carcinoma SCC Defect 53 mm 33 mm 22 mm Length Complications None None intraoral ulceration Follow up 7 mths 14 mths 18 mths RESULTS: In all patients distraction osteogenesis was succesful and adequate bone regeneration was achieved. There was neither pseudoarthrosis nor premature consolidation. The consolidation period ranged from 12 to 22 weeks before distractor device was removed. At the end of this period, the panoramic radiographs showed calcification of the maxilla gap. In patients 2 and 3 osseointegrated implants were placed in the new bone with an adequate osseointegration at short-term follow up.. Patient 1: Male of 38 years old who presented a right maxillary osteosarcoma. The patient was treated by means of surgical resection and reconstruction with a microvascular fibula free flap which was removed due to total necrosis. The postsurgical defect was of 53 mm. A double-step bone transport with stereolithography was performed for secondary reconstruction of the defect. New bone was generated along the defect. After the consolidation period anterior iliac crest onlay grafts were placed above the new formed bone to increase the width. Surgery at the stereolithographic model. First distraction osteogenesis. Second distraction osteogenesis.. Patient 2: Male of 72 years old with giant cell carcinoma who underwent ablative surgery at the anterior maxilla. Oronasal fístula was observed after the surgery and solved with a buccinator myomucosal flap. The patient was reconstructed by means of a trifocal distraction osteogenesis with two distraction devices. Osseointegrated implants were placed in the new bone.. Patient 3: Female of 54 years old who underwent posterior right maxillectomy due to squamous cell carcinoma. The bone was defect was of 22 mm. Primary reconstruction was performed by means of bichat bulla adipose flap and distraction. After the consolidation period new bone was generated along the defect. Anterior maxilla defect. Distraction devices.Distraction osteogenesis. New bone generated.Result after distractors removal and after implant placement.Final panoramic radiograph. Distraction process. BIBLIOGRAFY: 1. Ilizarov, G. A. Basic principle of transosseous compression and distraction osteogenesis. Ortop. Traumatol. Protez. 32: 7, 1971. 2. Herford, A.S. Use of a plate-guided distraction device for transport distraction osteogenesis of the mandible. J. Oral Maxillofac. Surg. 62. 412. 2004. 3. Rubio-Bueno, P; Naval Gías, L; Rodríguez Campo, F.J; Gil-Díez, J.L and Díaz González. Internal distraction osteogenesis for reconstruction of mandibular dsegmental defects: Preliminary clinical experience in five cases. J Oral Maxillofac Surg. 63: 528, 2005. 4. González-García, R; Rubio-Bueno, P; Naval Gías, L, et al. Internal distraction osteogenesis in mandibular reconstruction: clinical experience in 10 cases. Plast Reconstr Surg. 2008 Feb; 121(2): 563-75.