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An image-based approach to design and manufacture of scaffolds for maxillofacial reconstruction
026B - Maxillofacial reconstruction 12. An Image-Based Approach to Design and Manufacture of Scaffolds for Maxillofacial Reconstruction
Feinberg, S., Hollister, S., Chu, T., Halloran, J. University of Michigan, Ann Arbor, Michigan Tissue engineering has generated enthusiasm based on its potential for regeneration and reconstruction of tissues or organs using cells and/or molecular factors implanted in- or onto suitable carrier scaffolds. The majority of investigators have concentrated on the material make up and external geometry of the scaffold with minimal attention to the intraarchitectural design, hwestigators have shown that scaffold intra-architectural design (pore size, direction and interconnectivity of channels, trabecular wall orientation) can influence the diffusion pathways of nutrients, and mechanical compliance of the scaffold as well as the mechanical stimulus to invading or implanted cells. An "instructive" scaffold will be necessary to interface with the invading or implanted cells in order to continue the develoPment of the implanted scaffold construct in vivo. A protocol for constructing scaffolds, with site-specific intra-architectural design, for the ex vivo construction of osseous tissue using topology design algorithms to assess stress and strain within specific scaffold constructs will be presented. This will entail the use of image-based computational visualization, analysis and design methodology in conjunction with solid free-form fabrication manufacturing techniques to develop site-specific scaffolds for osseous reconstruction. A simulated example of temporomandibular joint reconstruction will be presented to illustrate this strategy. This approach is the first step in the development of an "instructive" scaffold with site-specific intra-architectural design and mechanical compliance that could be used for the tissue engineering and reconstruction of maxillofacial defects.
13. Comparative Evaluation of Contraction and Sulcus Depth Achieved by Clark's Technique Vestibuloplasty Operations Using Full-Thickness Skin Grafts and Solvent Dehydrated Human Pericardium
Alpaslan, G., Ekin, Y. Department of OMS, School of Dentistry, Gazi University, Ankara, Turkey Objectives For the correction of soft tissue abnormalities such as irritational fibrous hyperplasias or other conditions, elimination of high muscular attachment and compensation of inadequate ridges may neccessitate increasing the sulcular depth. Various techniques with or without utilizing grafts or other biomaterials have previously been described. This study was undertaken to evaluate the vestibular sulcus depth achieved by vestibuloplasty operations utilizing either full-thickness skin grafts (FTSG) or solvent dehydrated human pericardium (SDHP).
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Study design Twenty patients were randomly divided into groups and operated by standard Clark's vestibular extension procedure. Exposed wound surface was covered either autologous FTSG or SDHR The achieved vestibular depth and contraction was calculated by cephalometric and model analysis and clinically as well in a 9 months postoperative period Within group and between group statistical analysis were done by Student-test. Results The results of the study showed that no contraction was occurred mesiodistally but did in vestibular sulcus depth. Increase in vestibular sulcus depth achieved by Clark's vestibular extension procedure gradually decreased in both control and experimental groups. Conclusion Since SDHP provides acceptable wound contraction and vestibular sulcus depth with no morbidity, its use is recommended when host tissues are not available.
14. The Composite of Dense Polycrystal Particulate Hydroxylapatite (HA) and Plaster of Paris (PP) in the Repair of Oral and Maxillofacial Bone Deficiency
Shengwei, L., Weidong, T., Lei, L., Wei, T. College of Stomatology, West China University of Medical Sciences, Sichuan, Republic of China The reconstruction of oral and maxillofacial bone deficiency is a difficult problem involved many technical and theoretic puzzles. Whatever is the congenital or acquired oral and maxillofacial bone deficiency, it may lead to severe functional disorder and facial deformity. Although autogenous bone is good material, the second field of operation has to be made which increases patient pain and prolongs the operation time. At the same time, allotransplant also has some problems including absorbing and repulsive interaction. We use the composite of dense polycrystal particulate hydroxylapatite (HA) and plaster of paris (PP), with a chemical character very similar to human and animal bone, to correct the bone deficiency of oral and maxillofacial areas and get encouraging effects. 266 patients have been operated on in our department, 150 male, 116 female. The ages range from 21 to 65 years. The main applications include alveolar ridge widening and augmentation, maxilla alveolar cleft surgery, reconstruction of malar and orbit bone deficiency, filling of the bone cavities after operation of jaw cyst and osteomyelitis, filling of post extractional alveolar sockets, modified alveoloplasty and chin plasty. We have assayed 20 patients' blood concentration of IgG, IgA, IgM, C3, C4, CIC, etc among 266 patients. After statistical analysis procedure, its results indicate the preoperation and postoperation average level of IgG, IgA, IgM, C3, C4, CTC, etc has no significant difference. So we conclude H A - P P has no influence on humoral immunity. On the basis of different animal experiments, clinical application shows HA-PP has excellent histocompatibility without toxicity, stimulation and allergization. It cannot only
Feinberg, S., Hollister, S., Chu, T., Halloran, J. University of Michigan, Ann Arbor, Michigan Tissue engineering has generated enthusiasm based on its potential for regeneration and reconstruction of tissues or organs using cells and/or molecular factors implanted in- or onto suitable carrier scaffolds. The majority of investigators have concentrated on the material make up and external geometry of the scaffold with minimal attention to the intraarchitectural design, hwestigators have shown that scaffold intra-architectural design (pore size, direction and interconnectivity of channels, trabecular wall orientation) can influence the diffusion pathways of nutrients, and mechanical compliance of the scaffold as well as the mechanical stimulus to invading or implanted cells. An "instructive" scaffold will be necessary to interface with the invading or implanted cells in order to continue the develoPment of the implanted scaffold construct in vivo. A protocol for constructing scaffolds, with site-specific intra-architectural design, for the ex vivo construction of osseous tissue using topology design algorithms to assess stress and strain within specific scaffold constructs will be presented. This will entail the use of image-based computational visualization, analysis and design methodology in conjunction with solid free-form fabrication manufacturing techniques to develop site-specific scaffolds for osseous reconstruction. A simulated example of temporomandibular joint reconstruction will be presented to illustrate this strategy. This approach is the first step in the development of an "instructive" scaffold with site-specific intra-architectural design and mechanical compliance that could be used for the tissue engineering and reconstruction of maxillofacial defects.
13. Comparative Evaluation of Contraction and Sulcus Depth Achieved by Clark's Technique Vestibuloplasty Operations Using Full-Thickness Skin Grafts and Solvent Dehydrated Human Pericardium
Alpaslan, G., Ekin, Y. Department of OMS, School of Dentistry, Gazi University, Ankara, Turkey Objectives For the correction of soft tissue abnormalities such as irritational fibrous hyperplasias or other conditions, elimination of high muscular attachment and compensation of inadequate ridges may neccessitate increasing the sulcular depth. Various techniques with or without utilizing grafts or other biomaterials have previously been described. This study was undertaken to evaluate the vestibular sulcus depth achieved by vestibuloplasty operations utilizing either full-thickness skin grafts (FTSG) or solvent dehydrated human pericardium (SDHP).
55
Study design Twenty patients were randomly divided into groups and operated by standard Clark's vestibular extension procedure. Exposed wound surface was covered either autologous FTSG or SDHR The achieved vestibular depth and contraction was calculated by cephalometric and model analysis and clinically as well in a 9 months postoperative period Within group and between group statistical analysis were done by Student-test. Results The results of the study showed that no contraction was occurred mesiodistally but did in vestibular sulcus depth. Increase in vestibular sulcus depth achieved by Clark's vestibular extension procedure gradually decreased in both control and experimental groups. Conclusion Since SDHP provides acceptable wound contraction and vestibular sulcus depth with no morbidity, its use is recommended when host tissues are not available.
14. The Composite of Dense Polycrystal Particulate Hydroxylapatite (HA) and Plaster of Paris (PP) in the Repair of Oral and Maxillofacial Bone Deficiency
Shengwei, L., Weidong, T., Lei, L., Wei, T. College of Stomatology, West China University of Medical Sciences, Sichuan, Republic of China The reconstruction of oral and maxillofacial bone deficiency is a difficult problem involved many technical and theoretic puzzles. Whatever is the congenital or acquired oral and maxillofacial bone deficiency, it may lead to severe functional disorder and facial deformity. Although autogenous bone is good material, the second field of operation has to be made which increases patient pain and prolongs the operation time. At the same time, allotransplant also has some problems including absorbing and repulsive interaction. We use the composite of dense polycrystal particulate hydroxylapatite (HA) and plaster of paris (PP), with a chemical character very similar to human and animal bone, to correct the bone deficiency of oral and maxillofacial areas and get encouraging effects. 266 patients have been operated on in our department, 150 male, 116 female. The ages range from 21 to 65 years. The main applications include alveolar ridge widening and augmentation, maxilla alveolar cleft surgery, reconstruction of malar and orbit bone deficiency, filling of the bone cavities after operation of jaw cyst and osteomyelitis, filling of post extractional alveolar sockets, modified alveoloplasty and chin plasty. We have assayed 20 patients' blood concentration of IgG, IgA, IgM, C3, C4, CIC, etc among 266 patients. After statistical analysis procedure, its results indicate the preoperation and postoperation average level of IgG, IgA, IgM, C3, C4, CTC, etc has no significant difference. So we conclude H A - P P has no influence on humoral immunity. On the basis of different animal experiments, clinical application shows HA-PP has excellent histocompatibility without toxicity, stimulation and allergization. It cannot only