e8 Abstracts the bone implant in oncologic patients it is essential to conduct, among others, in vivo studies on animals. Materials and methods: A CT scan of the planned operation area (dorsum) will be made in one rat. A virtual model of scapulas will be made. PLGA composite scaffold will be produced in 3D printing method. Porous titanium scaffolds will be prototyped. In tissue engineering lab all scaffolds will be colonized with rat stem cells. The rats will be divided into 3 groups: group 1 autogenous bone transplant; group 2 PLGA scaffold, group 3 porous titanium scaffold. Two stages of operation under general anaesthesia are planned. In the first stage, in all groups, a fascio-cutaneous flap will be prepared. A part of scapula will be grafted. In the second stage, bone defects will be replaced with the according material, and the tissue complex will be fixed to the scapula. Observations and X-ray controls will be held weekly. After 3 months postoperatively all rats will be decapitated, CT scans will be made and tissue material will be grafted for histological analysis. Results: The presentation will encompass the up-to-date stages and achieved milestones of the research. Conclusion: The experiment will enable us to assess macro-, microscopic and mechanical characteristics of bioactive oncologic reconstruction methods of hard tissue in the head and neck. Conflict of interest: None declared. doi:10.1016/j.ijom.2011.07.1041 16 Treatment of TMJ ankylosis utilizing preoperative CT angiog- raphy, surgical navigation, and intraoperative ebolization D. Hoffman 1,* , T. Panetta 2 1 Oral & Maxillofacial Surgery, Staten Island University Hospital, Staten Island, NY, USA 2 Vascular Surgery, Staten Island University Hospital, Staten Island, NY, USA Treatment of TMJ ankylosis poses many risks and complex- ities beyond routine TMJ surgery. These risks include bleeding from a unaccessable artery, damage to adjacent structures such as intracranial, middle ear, and the infratemporal fossa. Our protocol includes preoperative planning with CT angiography and med- ical modeling, selective ebolization of branches of the external carotid system either preoperative or intraoperative with surgical exposure of the external carotid artery branches and surgical navi- gation (Brain Lab). This protocol has been used on 13 patients with TMJ ankylosis. All patients have been treated successfully with this protocol, and have not had any complications either intraop- eratively or postoperatively. Following the initial surgery a spacer was placed and a stage two total joint prosthesis was placed. Conflict of interest: I have received royalties from a TMJ prosthesis used in some of the patients. doi:10.1016/j.ijom.2011.07.1042 17 Sagittal split ramus osteotomy to prevent inferior alveolar nerve damage using the ultrasonic bone cutting device and endoscope J. Shimada Division of First Oral and Maxillofacial Surgery, Department of Diagnostic and Therapeutic Sciences, Meikai University School of Dentistry, Sakado, Japan Purpose: I will describe the sagittal split ramus osteotomy using the ultrasonic bone cutting device that we have recently begun to use in our institution to prevent inferior alveolar nerve damage and detail the operative procedure, which produces little nerve damage. Methods and materials: The osteotomy is started from the front edge of the mandibular ramus. When a complete split is made to the posterior edge, a Lindemann bur needs to be used for part of the horizontal osteotomy. It can be achieved with the view of endoscope. In lateral vertical osteotomy, three bone cuts (horizontal, anterior edge, vertical) are made consecutively and we attempt to split the bone with a splitter in order to reliably cut the cortical bone apart to the inferior edge. The location of the shallow nerve is confirmed, and if the splitter can be attached to the proximal bone fragment side, the separation can be accom- plished from the bone surface at this stage. The splitter is gradually opened larger, and the final split of the inferior edge is done with a largish osteotome in a portion selected so that the nerve will not be compressed. Bone fragment fixation is done with a single mini plate. Results: In recent 9 months, we performed 15 cases of SSRO with this presented method. Only one side had shown the slight paresthesia of mental region. The rate of nerve damage was only 3.3%, and it was smaller than one of the case series performed with saw and chisel. Conflict of interest: None declared. doi:10.1016/j.ijom.2011.07.1043 18 Development and optimization in Chile of the stereolitho- graphic biomodelling technology in the maxillofacial field A. Vargas 1,* , J. Ramos-Grez 2 1 Oncologic and Maxillofacial Surgery, Pontificia Universidad Catolica de Chile, Santiago de Chile, Chile 2 Mechanical Engineering Department, Pontificia Universidad Catolica de Chile, Santiago de Chile, Chile Introduction: Stereolithographic biomodels fabricated using rapid prototyping (RP) offer an undoubted contribution to max- illofacial surgery, especially in the study, planning and solving of complex cases. Not so long ago, these were available in Chile from abroad, however, not mimicking the bone on its physical properties, moreover with a 3D reproduction not always exact. Objective: To develop the RP technology in our country and to obtained bone biomodels with enhanced physical properties with respect to those imported, taking as a benchmark the properties of cortical bone. Methodology: The 3D Printing Z-Corporation ® technology was successfully transferred and implemented at the Pontificia Universidad Católica de Chile engineering laboratories. More than 100 testing specimens were 3D printed, at different print-