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Application of BMP-agarose composite in vivo
P21-5 Distraction osteogenesis and BMP 12. Application of BMP-Agarose Composite In Vivo
Kimura, y.1, Kawai, T.z, Ike, M. 1, Nagao, T.1, Hasegawa, j.2, Kawai, T.1 1Department of OMFS (2), 2Department of Dental Material Science, School of Dentistry, Aichi-Gakuin Univ., Nagoya, Japan For the application of BMP (Bone Morphogenetic Protein) in vivo, carrier materials are necessary to achieve stable new bone formation. Agarose was used as a carrier in this experiment. It has the property of forming an ideal gel with an open threedimensional network of fibres. BMP, used in this experiment, was extracted from bovine bone and partially purified by following the method of Ua~sT et al. Three kinds of experiments were held as follows. All the samples were implanted in the thigh muscle pouch of ddy mice. The hind limbs were examined by soft X-ray and histologically 3 weeks after implantation. Implantation of BMP alone. 5 mg of BMP was mixed with distilled water, and formed into a pellet. All of these samples induced new bone formation. Implantation of agarose alone. Samples of agarose alone were surrounded by the thin fibrous tissue layer, and no inflammatory cells were observed. Implantation of BMP-Agarose composite samples. Agarose (Sea Kern LE, F M C Co.) was melted in distilled water. The melted agarose and BMP, which contained 5mg of BMP in the final product, were mixed on a heated glass plate at 40 degrees C. A pellet was formed in a mold and lyophilized. All experimental specimens showed new bone formation, however histological observation showed less matured ossification compared with the result of BMP alone. The initial effects of BMP were thought to remain during the 3-week period due to the slow release of BMP from the BMP-Agarose composites, which continuously triggered the initiation of new bone formation.
13. Skeletal Stability Following Mandibular Distraction by Means of Step Osteotomy Technique
Kim, M. J., Jung, If. Y, Lira, Y H., Choi, W. J., Yoon, R Y, Lee, J. H., Kim, J. W. Department of Oral and Maxillofacial Surgery, College of Dentistry, Seoul National Univ., Seoul, Korea Since September 1994, we have treated 5 patients by gradual distraction of the mandible by means of a step osteotomy using an intraoral approach. This method has the following advantages. It increases bone contact between the segments and it tends to be less damaging to the inferior alveolar nerve.
173
A total of 8 sites in 5 patients with mandibular deficiencies were treated by this technique: Two children with hemifacial microsomia and 1 child with facial asymmetry and 2 adults with mandibular bony defects. The average amount of mandibular lengthening was 13 mm, ranging from 7 to 20 mm. In one 35 year old patient who had suffered from osteomyelitis at a young age, a compromised ossifcation occurred. In another patient distraction did not occur, requiring resplitting of the segments. No significant relapse has been observed in a 12 to 25 months follow-up period. In growing children, postsurgical orthodontic treatment is recommended to increase! postoperative skeletal stability and to induce normal mandibular growth.
14. Basic Study of Self Setting Alpha-Tricalcium Phosphate (Alpha-TCP) with Bone Morphogenetic Protein (BMP)
Ike, M. l, Kawai, T..2, Nagao, T, 1, Kimura, y1, Kawai, T..1 1The Second Department of OMFS and 2Department of Dental Material Science, School of Dent&try, Aichi-Gakuin University, Nagoya, Japan BMP carriers should have good biocompatibility, retain BMP activity and be easy to make in adequate amounts. Alpha-TCP is well known as a bioactive ceramic, and it shows good plasticity when used with hardening solutions. We studied the self-setting alpha-TCP-BMP composite, using four different hardening solutions: 75% Lactic Acid, 35% Malic Acid, 36% Polyacrylic Acid, and 0.3% Calcium bis monohydrate. BMP was extracted from bovine cortical bone. AlphaTCP was synthesized by means of a mechanochemical reaction. Five mg of BMP and 5 mg of alpha-TCP were mixed and then hardened by hardening solutions to make the composites (powder/liquid ratio=l.5). These composites were implanted in the hindquarter muscle pouch of mice. For the positive control, 5 mg of BMP alone was implanted in the same manner. The osteoinductive activities of the composites were examined three weeks after implantation by means of roentogenographic and histologic observations. The amounts of induced bone were determined by a computer supported image analysis system and histological mesh count. The alpha-TCP-BMP composites using 75% Lactic Acid and 35% Malic Acid induced much smaller amounts of new bone than the control. Alpha-TCP-BMP composites using 36% Polyacrylic Acid induced almost the same amount of new bone as the control. The alpha-TCP-BMP composites using 0.3% Calcium bis monohydrate, however, showed good biocompatibility and large amounts of new bone formation, significantly more than that of the positive control (P<0.05).
Kimura, y.1, Kawai, T.z, Ike, M. 1, Nagao, T.1, Hasegawa, j.2, Kawai, T.1 1Department of OMFS (2), 2Department of Dental Material Science, School of Dentistry, Aichi-Gakuin Univ., Nagoya, Japan For the application of BMP (Bone Morphogenetic Protein) in vivo, carrier materials are necessary to achieve stable new bone formation. Agarose was used as a carrier in this experiment. It has the property of forming an ideal gel with an open threedimensional network of fibres. BMP, used in this experiment, was extracted from bovine bone and partially purified by following the method of Ua~sT et al. Three kinds of experiments were held as follows. All the samples were implanted in the thigh muscle pouch of ddy mice. The hind limbs were examined by soft X-ray and histologically 3 weeks after implantation. Implantation of BMP alone. 5 mg of BMP was mixed with distilled water, and formed into a pellet. All of these samples induced new bone formation. Implantation of agarose alone. Samples of agarose alone were surrounded by the thin fibrous tissue layer, and no inflammatory cells were observed. Implantation of BMP-Agarose composite samples. Agarose (Sea Kern LE, F M C Co.) was melted in distilled water. The melted agarose and BMP, which contained 5mg of BMP in the final product, were mixed on a heated glass plate at 40 degrees C. A pellet was formed in a mold and lyophilized. All experimental specimens showed new bone formation, however histological observation showed less matured ossification compared with the result of BMP alone. The initial effects of BMP were thought to remain during the 3-week period due to the slow release of BMP from the BMP-Agarose composites, which continuously triggered the initiation of new bone formation.
13. Skeletal Stability Following Mandibular Distraction by Means of Step Osteotomy Technique
Kim, M. J., Jung, If. Y, Lira, Y H., Choi, W. J., Yoon, R Y, Lee, J. H., Kim, J. W. Department of Oral and Maxillofacial Surgery, College of Dentistry, Seoul National Univ., Seoul, Korea Since September 1994, we have treated 5 patients by gradual distraction of the mandible by means of a step osteotomy using an intraoral approach. This method has the following advantages. It increases bone contact between the segments and it tends to be less damaging to the inferior alveolar nerve.
173
A total of 8 sites in 5 patients with mandibular deficiencies were treated by this technique: Two children with hemifacial microsomia and 1 child with facial asymmetry and 2 adults with mandibular bony defects. The average amount of mandibular lengthening was 13 mm, ranging from 7 to 20 mm. In one 35 year old patient who had suffered from osteomyelitis at a young age, a compromised ossifcation occurred. In another patient distraction did not occur, requiring resplitting of the segments. No significant relapse has been observed in a 12 to 25 months follow-up period. In growing children, postsurgical orthodontic treatment is recommended to increase! postoperative skeletal stability and to induce normal mandibular growth.
14. Basic Study of Self Setting Alpha-Tricalcium Phosphate (Alpha-TCP) with Bone Morphogenetic Protein (BMP)
Ike, M. l, Kawai, T..2, Nagao, T, 1, Kimura, y1, Kawai, T..1 1The Second Department of OMFS and 2Department of Dental Material Science, School of Dent&try, Aichi-Gakuin University, Nagoya, Japan BMP carriers should have good biocompatibility, retain BMP activity and be easy to make in adequate amounts. Alpha-TCP is well known as a bioactive ceramic, and it shows good plasticity when used with hardening solutions. We studied the self-setting alpha-TCP-BMP composite, using four different hardening solutions: 75% Lactic Acid, 35% Malic Acid, 36% Polyacrylic Acid, and 0.3% Calcium bis monohydrate. BMP was extracted from bovine cortical bone. AlphaTCP was synthesized by means of a mechanochemical reaction. Five mg of BMP and 5 mg of alpha-TCP were mixed and then hardened by hardening solutions to make the composites (powder/liquid ratio=l.5). These composites were implanted in the hindquarter muscle pouch of mice. For the positive control, 5 mg of BMP alone was implanted in the same manner. The osteoinductive activities of the composites were examined three weeks after implantation by means of roentogenographic and histologic observations. The amounts of induced bone were determined by a computer supported image analysis system and histological mesh count. The alpha-TCP-BMP composites using 75% Lactic Acid and 35% Malic Acid induced much smaller amounts of new bone than the control. Alpha-TCP-BMP composites using 36% Polyacrylic Acid induced almost the same amount of new bone as the control. The alpha-TCP-BMP composites using 0.3% Calcium bis monohydrate, however, showed good biocompatibility and large amounts of new bone formation, significantly more than that of the positive control (P<0.05).