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O.228 Mandibular reconstruction using stereolithographic models
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Journal of Cranio-Maxillofacial Surgery 34(2006) Suppl. S1
stress of the surgeon and brings a very useful teaching tool in the operative theatre. The main drawbacks are its poor ergonomy and its cost. O.227 A new project for medical rapid prototyping technologies in maxillofacial surgery S. Stea1 , E. Sarti1 , L. Lancellotti1 , M. Moretti2 . 1 Department of Maxillofacial Surgery, Villa Maria Cecilia Hospital, Cotignola (Ra), Italy; 2 Academic Spin out, University of Bologna, HRS-CPS, Italy Current reconstructive techniques of the facial skeleton in the reconstruction of the cranio-orbital defects following tumour resections or fractures include autogenous bone and biomaterials. The surgeons usually employed autologous bone or biomaterials empirically and manually modelled with good result, but today new technologies are available. Medical rapid prototyping (MRP) is defined as a manufacture of dimensionally accurate physical models of human anatomy derived from medical image data using a variety of rapid prototyping technologies. Rapid prototyping is a generic name given to a range of related technologies that may be used to fabricate physical objects (computer-aided manufacturing: CAM) directly from CAD (computer-aided design) data sources. The authors describe software and hardware requirements for the manufacture of high-quality medical models made by means of medical rapid prototyping. They process the TC and MRI data, using also 3D reconstructions to visualize and quantify the hard and soft tissues deficit (reverse engineering). They utilize a software, via internet, which allows interaction between surgeon and 3D designer in the defining of all prototype’s aspects especially to view soft tissues modifications before its manufacturing. The surgery’s accuracy is improved by a frame of 3D navigation system. O.228 Mandibular reconstruction using stereolithographic models N. Pigadas, P. Sen, S. Whitley, B. Musgrove. Maxillofacial Unit, Central Manchester and Manchester Children’s University Hospitals NHS Trust, UK The mandible is an integral component of oral function and facial aesthetics. Accurate reconstruction of segmental defects permits the patient to return to a reasonable quality of life. Stereolithographic models are anatomically accurate three-dimensional (3D) models constructed from Computerized Tomography (CT) data. They can greatly facilitate diagnosis, patient information, surgery simulation, contouring of reconstruction plates and preparation of joint prostheses. The objective of this paper is to present our experience in 3D model assisted mandibular reconstruction. Materials and Methods: We present a series of patients treated over the last 3 years in our Unit. All patients underwent segmental mandibulectomies for tumour ablation or the treatment of osteoradionecrosis. Immediate reconstruction of the continuity defects was carried out with osseous or composite free flaps and was assisted by the use of stereolithographic models. These were fabricated from acrylic photo-polymerising resin using data from the preoperative staging CT scan. They were used for preoperative planning of the resection, selection of the donor site, adaptation of the reconstruction plate, orientation of the plate using anatomical landmarks and estimation of the length of the required screws. Estimation of the anatomical accuracy of the reconstruction was carried out comparing preoperative and postoperative Orthopantomograms and Posteroanterior X-rays of the mandible. Patients were also assessed pre-operatively and
Abstracts, EACFMS XVIII Congress postoperatively with the University of Washington Quality of Life Scale (UW-QOL). Results: Mandibular reconstruction assisted by stereolithography enables satisfactory return to the pre-morbid form and function. The postoperative results and UW-QOL assessments of our patients will be presented in detail. O.229 Learning by doing – Virtual surgical training N. von Sternberg-Gospos1 , M. Heiland1 , P. Pohlenz1 , R. Schmelzle2 , A. Petersik2 , U. Tiede2 , J. Wiltfang3 , I. Springer3 . 1 Department of Oral and Maxillofacial Surgery, University of Hamburg, Germany; 2 VOXEL-MAN Group, University Medical Center Hamburg-Eppendorf, Germany; 3 Department of Oral and Maxillofacial Surgery, University of Kiel, Germany Introduction and Objectives: Surgical trainees take longer to complete particular procedures and encounter an increased rate of complications even under the direct supervision of an experienced surgeon. Selective reduction of bone without collateral damage (i.e. nerves, etc.) is an essential oral surgical technique. Material and Methods: A virtual three-dimensional model of a pig skull was created based on CT data. Inferior alveolar nerves and teeth were virtually simulated. A realistic drilling sensation was achieved with a force-feedback system. We have compared two groups of trainees (n = 20 each) one of which received computer-based virtual surgical training (VOXEL-MANsystem) before performing apicectomy in a pig cadaver model. The following parameters were evaluated: preservation of vital structures, defect volume, extent of resection and the time needed to complete the procedure. Assessment by qualified trainers was compared with self-assessment by the trainees. Results: The consequent visual and tactile sensations appeared to be completely authentic. Amongst other findings, we showed that the chance of preserving vital neighbouring structures was increased six fold after virtual surgical training (p < 0.001). Most importantly, the ability to objectively self-assess performance was significantly improved in this group (p < 0.001). Conclusions: It is possible today to realistically simulate bone surgery procedures, even in complex anatomical models. An exciting extension of the available technology would entail the addition of virtual pathologies and the adaptation of anonymous patient data sets to extend the range of simulated surgical procedures. The virtual training system investigated in this report has proven to be a valuable educational tool in oral surgery. O.230 Computer-aided dental implant planning – An integrated approach T. Dreiseidler1 , R.A. Mischkowski2 , J. Neugebauer2 , J.E. Z¨oller2 , E. Keeve1 . 1 Surgical Systems Laboratory, CAESAR – Center of advanced European Studies and research, Bonn, Germany; 2 Department for Craniomaxillofacial and Plastic Surgery, University of Cologne, Germany Introduction and Objectives: Today surgical drill guides based computer-aided dental implant planning are available but users have to handle several pieces of software, specific radiological protocols and data transfer from the radiologist. The aim of this study was to evaluate an integrated system for computer-aided implant planning consisting of a 3D cone beam scanner including software for planning and producing surgical drill guides (Sirona, Bensheim). Material and Methods: 25 patients were scanned, producing a 3D dataset visualizing all relevant anatomy for implant planning. Patients were divided in two groups, for 13 patients in group A, a scan prosthesis was applied for scanning and the scanner
Journal of Cranio-Maxillofacial Surgery 34(2006) Suppl. S1
stress of the surgeon and brings a very useful teaching tool in the operative theatre. The main drawbacks are its poor ergonomy and its cost. O.227 A new project for medical rapid prototyping technologies in maxillofacial surgery S. Stea1 , E. Sarti1 , L. Lancellotti1 , M. Moretti2 . 1 Department of Maxillofacial Surgery, Villa Maria Cecilia Hospital, Cotignola (Ra), Italy; 2 Academic Spin out, University of Bologna, HRS-CPS, Italy Current reconstructive techniques of the facial skeleton in the reconstruction of the cranio-orbital defects following tumour resections or fractures include autogenous bone and biomaterials. The surgeons usually employed autologous bone or biomaterials empirically and manually modelled with good result, but today new technologies are available. Medical rapid prototyping (MRP) is defined as a manufacture of dimensionally accurate physical models of human anatomy derived from medical image data using a variety of rapid prototyping technologies. Rapid prototyping is a generic name given to a range of related technologies that may be used to fabricate physical objects (computer-aided manufacturing: CAM) directly from CAD (computer-aided design) data sources. The authors describe software and hardware requirements for the manufacture of high-quality medical models made by means of medical rapid prototyping. They process the TC and MRI data, using also 3D reconstructions to visualize and quantify the hard and soft tissues deficit (reverse engineering). They utilize a software, via internet, which allows interaction between surgeon and 3D designer in the defining of all prototype’s aspects especially to view soft tissues modifications before its manufacturing. The surgery’s accuracy is improved by a frame of 3D navigation system. O.228 Mandibular reconstruction using stereolithographic models N. Pigadas, P. Sen, S. Whitley, B. Musgrove. Maxillofacial Unit, Central Manchester and Manchester Children’s University Hospitals NHS Trust, UK The mandible is an integral component of oral function and facial aesthetics. Accurate reconstruction of segmental defects permits the patient to return to a reasonable quality of life. Stereolithographic models are anatomically accurate three-dimensional (3D) models constructed from Computerized Tomography (CT) data. They can greatly facilitate diagnosis, patient information, surgery simulation, contouring of reconstruction plates and preparation of joint prostheses. The objective of this paper is to present our experience in 3D model assisted mandibular reconstruction. Materials and Methods: We present a series of patients treated over the last 3 years in our Unit. All patients underwent segmental mandibulectomies for tumour ablation or the treatment of osteoradionecrosis. Immediate reconstruction of the continuity defects was carried out with osseous or composite free flaps and was assisted by the use of stereolithographic models. These were fabricated from acrylic photo-polymerising resin using data from the preoperative staging CT scan. They were used for preoperative planning of the resection, selection of the donor site, adaptation of the reconstruction plate, orientation of the plate using anatomical landmarks and estimation of the length of the required screws. Estimation of the anatomical accuracy of the reconstruction was carried out comparing preoperative and postoperative Orthopantomograms and Posteroanterior X-rays of the mandible. Patients were also assessed pre-operatively and
Abstracts, EACFMS XVIII Congress postoperatively with the University of Washington Quality of Life Scale (UW-QOL). Results: Mandibular reconstruction assisted by stereolithography enables satisfactory return to the pre-morbid form and function. The postoperative results and UW-QOL assessments of our patients will be presented in detail. O.229 Learning by doing – Virtual surgical training N. von Sternberg-Gospos1 , M. Heiland1 , P. Pohlenz1 , R. Schmelzle2 , A. Petersik2 , U. Tiede2 , J. Wiltfang3 , I. Springer3 . 1 Department of Oral and Maxillofacial Surgery, University of Hamburg, Germany; 2 VOXEL-MAN Group, University Medical Center Hamburg-Eppendorf, Germany; 3 Department of Oral and Maxillofacial Surgery, University of Kiel, Germany Introduction and Objectives: Surgical trainees take longer to complete particular procedures and encounter an increased rate of complications even under the direct supervision of an experienced surgeon. Selective reduction of bone without collateral damage (i.e. nerves, etc.) is an essential oral surgical technique. Material and Methods: A virtual three-dimensional model of a pig skull was created based on CT data. Inferior alveolar nerves and teeth were virtually simulated. A realistic drilling sensation was achieved with a force-feedback system. We have compared two groups of trainees (n = 20 each) one of which received computer-based virtual surgical training (VOXEL-MANsystem) before performing apicectomy in a pig cadaver model. The following parameters were evaluated: preservation of vital structures, defect volume, extent of resection and the time needed to complete the procedure. Assessment by qualified trainers was compared with self-assessment by the trainees. Results: The consequent visual and tactile sensations appeared to be completely authentic. Amongst other findings, we showed that the chance of preserving vital neighbouring structures was increased six fold after virtual surgical training (p < 0.001). Most importantly, the ability to objectively self-assess performance was significantly improved in this group (p < 0.001). Conclusions: It is possible today to realistically simulate bone surgery procedures, even in complex anatomical models. An exciting extension of the available technology would entail the addition of virtual pathologies and the adaptation of anonymous patient data sets to extend the range of simulated surgical procedures. The virtual training system investigated in this report has proven to be a valuable educational tool in oral surgery. O.230 Computer-aided dental implant planning – An integrated approach T. Dreiseidler1 , R.A. Mischkowski2 , J. Neugebauer2 , J.E. Z¨oller2 , E. Keeve1 . 1 Surgical Systems Laboratory, CAESAR – Center of advanced European Studies and research, Bonn, Germany; 2 Department for Craniomaxillofacial and Plastic Surgery, University of Cologne, Germany Introduction and Objectives: Today surgical drill guides based computer-aided dental implant planning are available but users have to handle several pieces of software, specific radiological protocols and data transfer from the radiologist. The aim of this study was to evaluate an integrated system for computer-aided implant planning consisting of a 3D cone beam scanner including software for planning and producing surgical drill guides (Sirona, Bensheim). Material and Methods: 25 patients were scanned, producing a 3D dataset visualizing all relevant anatomy for implant planning. Patients were divided in two groups, for 13 patients in group A, a scan prosthesis was applied for scanning and the scanner