- Email: [email protected]
Long-term experiences with calvarial bone grafts in cranio-maxillo-facial surgery
Free oral communications essential to develop the use of the distraction osteogenesis in correction of other craniofacial malformations.
Regional Flaps in Reconstructive Surgery after Tumour Resection
Kowalik S., Wiktor A., Mysliwiec L., Halczy-Kowalik L. Department of Maxillofacial Surgery, Szczecin, Poland The aim of the papers is estimation of the 360 regional flaps in reconstructive surgery after resection of the tumours of the head and neck. The authors have used different kinds of regional flaps. Most useful was a group of flaps nourished by direct cutaneous arteries that course along the long axis of flaps. In this group of 159 forehead flaps were 71 horizontal and 88 midline vertical flaps. These flaps were used in reconstruction of the nose, skull base, tongue and cheek. 133 myocutaneous flaps from the pectoralis major muscle were established in two modifications. Island and full-thickness wedge shaped pedicled flaps. These kinds of flap were used in reconstruction of the lower part of the face, mostly after resection of the front part of the mouth. 51 flaps were established from the cervical region; most of them were based on the neck. They were used for resurfacing cheek and internal lining of the stoma. Twenty-nine flaps were deltopectoral or thoracoacromial flaps. Advantages and disadvantages of these flaps will be discussed. Because of the necrosis we have lost 2.5% forehead flaps and 8% myocutaneous and other flaps.
Long-Term Experiences with Calvarial Bone Grafts in Cranio-Maxillo-Facial Surgery Koz~k J., Voska P.
Department of Maxillofacial Surgery, 2nd Medical Faculty, Charles University, Prague, Czech Republic The authors present their 10 year's experiences of reconstruction with calvarial bone grafts in children and adult patients. Calvarial bone grafts were used for the reconstruction of the posttraumatic defects, defects originated after tumour removal and craniofacial anomalies. The reconstruction was provided by the calvarial bone grafts in the full thickness, splitting bone grafts or taken only from the outside of the bone. Part of the calvarial bone grafts were used like a vascularized bone with facial or muscle stalk. They reconstructed the skull, forehead, nose, zygoma, floor of the orbit, maxilla and mandible by the calvarial bone grafts. No serious preoperative or postoperative complications appeared in any of the 95 patients. In 10% of the cases, when bone grafts were used like onlays, the authors observed a resorption of up to 20% of the volume.
Indication and Value of Different Methods of ThreeDimensional-Modelling in Cranio-Facial Operative Procedures Kreusch Z 1, Lambrecht J. 7".2, Hezel j.3
1Department of Oral and Maxillofacial Surgery, University of Kiel, Kiel, Germany 2University of Basel, Switzerland 3Radiological Practice, Kiel, Germany
65
Three-dimensional (3-D) modelling from computed tomography (CT) data has been performed as an ideal method of obtaining information about the bony situation of the skull before reparative or corrective procedures. It can help to simulate osteoplastic procedures, to select the ideal bony transplant, depending from size and shape of the defect, to educate young surgeons and consequently reduce operation time. Three types of models are used, styrodur milling models, models based on laser technology like stereolithography and lasersintering. Since 1985 we have performed 3-D modelling in 134 patients. Indications are bony defects after turnout or trauma surgery, craniofacial malformations and others like preimplantological planning. The milling model can be easily milled from a styrodur block; a disadvantage is the difficulty in milling intrabony spaces. Therefore, in cases of craniofacial corrective procedures of the full skull, two half models can be fabricated to show the interior aspect of the skull base. For these indications we prefer models based on laser technology. Laser hardened acrylic resins can show cavities like sinuses or the skull base. If an exact postoperative occlusion is necessary, dental impressions are taken, and the dental arches from the models are replaced with those from plaster which are positioned into the model with a face bow. Exact occlusal splints can now be fabricated for the postoperative situation. The milling model is the model of choice when any operative procedure has to be simulated, and osteosynthesis shall be performed on a model. The material is easy to work with and the costs are acceptable. Lasersintering or stereolithography models have to be fabricated when intrabony cavities are involved in the operative procedure.
Inductive Properties of Recombinant Human BMP-2 and Human BMP-4 Expressed in Escherichia Coli Kiibler N.R. l, Reuther ,I.E. 1, Ruppert R. 2, Sebald W.2
Departments of 1Oral and Maxillofacial Surgery and 2physiological Chemistry, Bayerische Julius-Maximillians University, Wiirzburg, Germany Within the last years several bone morphogenetic proteins (BMPs) have been characterized and cloned. Most of the BMPs belong to the growth factor superfamily of TGF-a, and some of them possess osteoinductive properties in vivo. Hitherto, rhBMPs have only been produced by mammalian expression systems. In the following we report an instance of the expression of BMP-2 by E. coli. m R N A was isolated from the osteosarcoma cell line U2OS. Using poly(A+)mRNA, dscDNA was synthesized and amplified using PCR. The D N A fragment was cloned in an expression vector, which was transferred into E. coli. The monomeric form ~ f BMP-2 was found within inclusion bodies, renatured (gimerized) and purified by means of HPLC. cDNA as well as the mature protein were sequenced and found to correspond to rhBMP-2. The active homodimer of BMP-2 showed a M W of 25.8 kDa. The purity of the protein preparations was estimated at approximately 98% by means of silver stain. In vitro rhBMP2 was incubated together with neonatal rat muscle tissue for 4 h followed by an incubation period of 14 days on cellulose acetate membranes in BMP-free medium. Already 0.4 gg rhBMP-2 induced chondroneogenesis in 5 out of 15 samples, while 4 gg as well as 40 gg rhBMP-2 showed cartilage formation in 11 out of 16 samples. In vivo rhBMP-2 was implanted intramuscularly for 3 weeks in ICR mice. Amounts of 4 pg rhBMP-2 and more induced in 15 out of 17 samples a heterotopic bone formation. Thereby ossicles were formed which contained hematopoetic active bone marrow. The results show that the application of a single morphogen,
Regional Flaps in Reconstructive Surgery after Tumour Resection
Kowalik S., Wiktor A., Mysliwiec L., Halczy-Kowalik L. Department of Maxillofacial Surgery, Szczecin, Poland The aim of the papers is estimation of the 360 regional flaps in reconstructive surgery after resection of the tumours of the head and neck. The authors have used different kinds of regional flaps. Most useful was a group of flaps nourished by direct cutaneous arteries that course along the long axis of flaps. In this group of 159 forehead flaps were 71 horizontal and 88 midline vertical flaps. These flaps were used in reconstruction of the nose, skull base, tongue and cheek. 133 myocutaneous flaps from the pectoralis major muscle were established in two modifications. Island and full-thickness wedge shaped pedicled flaps. These kinds of flap were used in reconstruction of the lower part of the face, mostly after resection of the front part of the mouth. 51 flaps were established from the cervical region; most of them were based on the neck. They were used for resurfacing cheek and internal lining of the stoma. Twenty-nine flaps were deltopectoral or thoracoacromial flaps. Advantages and disadvantages of these flaps will be discussed. Because of the necrosis we have lost 2.5% forehead flaps and 8% myocutaneous and other flaps.
Long-Term Experiences with Calvarial Bone Grafts in Cranio-Maxillo-Facial Surgery Koz~k J., Voska P.
Department of Maxillofacial Surgery, 2nd Medical Faculty, Charles University, Prague, Czech Republic The authors present their 10 year's experiences of reconstruction with calvarial bone grafts in children and adult patients. Calvarial bone grafts were used for the reconstruction of the posttraumatic defects, defects originated after tumour removal and craniofacial anomalies. The reconstruction was provided by the calvarial bone grafts in the full thickness, splitting bone grafts or taken only from the outside of the bone. Part of the calvarial bone grafts were used like a vascularized bone with facial or muscle stalk. They reconstructed the skull, forehead, nose, zygoma, floor of the orbit, maxilla and mandible by the calvarial bone grafts. No serious preoperative or postoperative complications appeared in any of the 95 patients. In 10% of the cases, when bone grafts were used like onlays, the authors observed a resorption of up to 20% of the volume.
Indication and Value of Different Methods of ThreeDimensional-Modelling in Cranio-Facial Operative Procedures Kreusch Z 1, Lambrecht J. 7".2, Hezel j.3
1Department of Oral and Maxillofacial Surgery, University of Kiel, Kiel, Germany 2University of Basel, Switzerland 3Radiological Practice, Kiel, Germany
65
Three-dimensional (3-D) modelling from computed tomography (CT) data has been performed as an ideal method of obtaining information about the bony situation of the skull before reparative or corrective procedures. It can help to simulate osteoplastic procedures, to select the ideal bony transplant, depending from size and shape of the defect, to educate young surgeons and consequently reduce operation time. Three types of models are used, styrodur milling models, models based on laser technology like stereolithography and lasersintering. Since 1985 we have performed 3-D modelling in 134 patients. Indications are bony defects after turnout or trauma surgery, craniofacial malformations and others like preimplantological planning. The milling model can be easily milled from a styrodur block; a disadvantage is the difficulty in milling intrabony spaces. Therefore, in cases of craniofacial corrective procedures of the full skull, two half models can be fabricated to show the interior aspect of the skull base. For these indications we prefer models based on laser technology. Laser hardened acrylic resins can show cavities like sinuses or the skull base. If an exact postoperative occlusion is necessary, dental impressions are taken, and the dental arches from the models are replaced with those from plaster which are positioned into the model with a face bow. Exact occlusal splints can now be fabricated for the postoperative situation. The milling model is the model of choice when any operative procedure has to be simulated, and osteosynthesis shall be performed on a model. The material is easy to work with and the costs are acceptable. Lasersintering or stereolithography models have to be fabricated when intrabony cavities are involved in the operative procedure.
Inductive Properties of Recombinant Human BMP-2 and Human BMP-4 Expressed in Escherichia Coli Kiibler N.R. l, Reuther ,I.E. 1, Ruppert R. 2, Sebald W.2
Departments of 1Oral and Maxillofacial Surgery and 2physiological Chemistry, Bayerische Julius-Maximillians University, Wiirzburg, Germany Within the last years several bone morphogenetic proteins (BMPs) have been characterized and cloned. Most of the BMPs belong to the growth factor superfamily of TGF-a, and some of them possess osteoinductive properties in vivo. Hitherto, rhBMPs have only been produced by mammalian expression systems. In the following we report an instance of the expression of BMP-2 by E. coli. m R N A was isolated from the osteosarcoma cell line U2OS. Using poly(A+)mRNA, dscDNA was synthesized and amplified using PCR. The D N A fragment was cloned in an expression vector, which was transferred into E. coli. The monomeric form ~ f BMP-2 was found within inclusion bodies, renatured (gimerized) and purified by means of HPLC. cDNA as well as the mature protein were sequenced and found to correspond to rhBMP-2. The active homodimer of BMP-2 showed a M W of 25.8 kDa. The purity of the protein preparations was estimated at approximately 98% by means of silver stain. In vitro rhBMP2 was incubated together with neonatal rat muscle tissue for 4 h followed by an incubation period of 14 days on cellulose acetate membranes in BMP-free medium. Already 0.4 gg rhBMP-2 induced chondroneogenesis in 5 out of 15 samples, while 4 gg as well as 40 gg rhBMP-2 showed cartilage formation in 11 out of 16 samples. In vivo rhBMP-2 was implanted intramuscularly for 3 weeks in ICR mice. Amounts of 4 pg rhBMP-2 and more induced in 15 out of 17 samples a heterotopic bone formation. Thereby ossicles were formed which contained hematopoetic active bone marrow. The results show that the application of a single morphogen,