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Inductive properties of recombinant human BMP-2 and human BMP-4 expressed in Escherichia coli
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,
66 Journal of Cranio-Maxillofacial Surgery in this case BMP-2, is sufficient to induce hard tissue formation. Thereby the concentration of BMP-2 necessary to differentiate mesenchymal cells into chondro- and osteoblasts is extremely low. This is the first report about the production of recombinant BMP-2 in E. eoli. This bacterial expression system is much more productive then the mammalian systems used so far. It opens the possibility for the industrial production of rhBMPs. Final experimental studies in highly developed animals as well as first clinical studies with BMP-2 are in progress.
immediate availability, no donor site morbidity, universal applicability (cranial/orbital/sinus defects, comminuted fractures), three-dimensional reconstruction of complex anatomic structures is easily performed, combination with bone or cartilage grafts is possible and extremely low susceptibility to infection. The operative technique and the aesthetic and functional results after reconstruction with microtitanium augmentation mesh and dynamic mesh are discussed in detail.
Anatomical Study of the Lateral Orbital Flap
Dental Implants and Steinhiiuser's Floor-of-the-MouthPlasty for Improvement of Oral Function in Tumour Patients
Kusumoto K., Ogawa Y.
Kwakman J.M., Voorsmit R.A.C.A., Freihofer H.P.M.
Department of Plastic and Reconstructive Surgery, Kansai Medical University, Osaka, Japan
Department of Oral and Maxillofacial Surgery, Academic Hospital Nijmegen, Nijmegen, The Netherlands
A lateral orbital flap (LOF), as a subcutaneous pedicle flap (SCPF), has proved very beneficial for the reconstruction of the relatively small facial defect of peripalpebral and periorbital region. To clarify the vascularity of the region, the authors have conducted an angiographic study using cadavers. This study has found that the local specific vascularity is a centripetal pattern to the palpebral fissure, and there is a vascular arcade between zygomatico-orbital and zygomatico-facial arteries (ZOA-ZFA arcade). Further radiographic LOF inspection indicates that feeding is attributed to a mimic muscle in this axial pattern vascularity. Until now, the SCPF vascular support system has been thought to present a random pattern. However, this study has shown that when planed SCPFs, such as a LOF that has a local specific vascular direction, the arterial arcade or a cutaneous branch that passed through a mimic muscle can be used to supply them.
Introduction: Oral functions like speaking, chewing and swallowing are often reduced after ablative tumour surgery in mouth and oropharynx. For restoration of at least a part of these functions, stable dentures and satisfactory mobility of the tongue are necessary. Dental implants can be used to achieve a stable denture. Preimplant surgery, however, is often needed to reduce the amount of bulky tissue when myocutaneous flaps have been used for reconstruction. Besides, mobility of the tongue should be adequate.
Results after Reconstruction of Craniofacial Defect with Microtitanium Augmentation Mesh and Dynamic Mesh
Kuttenberger J.J., Hardt N., Kessler P. Department of Oral and Maxillofacial Surgery, Kantonsspital Luzern, Luzern, Switzerland Different operative techniques are used for reconstruction of craniofacial defects: cranioplasty with autogenous bone (calvaria, rib, iliac crest), cranioplasty with allogenous bone (AAA-bone) or cranioplasty with alloplastic materials (titanium mesh, methacrylate). At the Department of Oral and Maxillofacial Surgery, Kantonsspital Luzern, 10 patients with defects in the craniofacial and orbito-ethmoidal region have been treated using titanium micromesh during the last 5 years. Two different mesh systems (microtitanium augmentation mesh, dynamic mesh) have been used for reconstruction in non load-bearing areas. In 4 patients the defects were caused by acute trauma with comminuted fractures and bone loss, 4 patients showed extensive contour defects after former craniotomies, in 2 patients extensive residual defects after previous osteomyelitis of the frontal bone had to be restored. The microtitanium augmentation mesh or dynamic mesh are used for reconstruction in the following indications: immediate reconstruction in the primary treatment of comminuted fractures with bone loss in non load-beating areas, treatment of extensive contour disturbances in combination with bone or cartilage grafts, and reconstruction of areas with high risk of infection. Advantages of this reconstructive technique are
Materials and Methods: Twelve patients have been treated for improvement of oral functions after tumour surgery between 1992-1995, with a mean follow-up of 11.6 months. A combination of reduction of bulky tissue, insertion of dental implants and Steinhfiuser's floor-of-the-mouthplasty for improvement of the mobility of the tongue will be presented. Results: All patients reported an improved tongue mobility. Of the 10 patients in whom the dental treatment is completed, 9 patients stated that they are able to chew food. One patient does not chew because he can only swallow liquids, however he states that his speaking has been improved. Two patients complained that the improvement was less than they expected, both patients have a partial anaesthesia of their tongue caused by the tumour surgery. In 2 patients an additional conventional lowering of the floor of the mouth was performed during abutment placement. Conclusion: From our results it may be stated that Steinh~iuser's floor-of-the-mouth-plasty with secondary epithelialization in combination with osseointegrated implants is a simple, reliable and effective method for improvement of oral function in tumour patients.
Evaluation of Blood Supply in Free-Flaps by a New Non-Invasive Technique
Lang M. 1, Kern R), Kiircher Ho 1, Rienmiiller R )
Departments of 1Maxillofacial Surgery and :General Radiological Diagnostics, Medical School, Universityof Graz, Graz, Austria Thorough and continuous monitoring (in particular systemic blood pressure, central venous pressure) is mandatory during the first 48 h after surgery. Early detection of disturbed perfusion in the graft is essential for timely revision surgery of the vessel connections. Graft perfusion was evaluated by an (EBCT) (electron beam computer tomography flow study of a single 6 mm slice (exposure 300 ms, interscan
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,
66 Journal of Cranio-Maxillofacial Surgery in this case BMP-2, is sufficient to induce hard tissue formation. Thereby the concentration of BMP-2 necessary to differentiate mesenchymal cells into chondro- and osteoblasts is extremely low. This is the first report about the production of recombinant BMP-2 in E. eoli. This bacterial expression system is much more productive then the mammalian systems used so far. It opens the possibility for the industrial production of rhBMPs. Final experimental studies in highly developed animals as well as first clinical studies with BMP-2 are in progress.
immediate availability, no donor site morbidity, universal applicability (cranial/orbital/sinus defects, comminuted fractures), three-dimensional reconstruction of complex anatomic structures is easily performed, combination with bone or cartilage grafts is possible and extremely low susceptibility to infection. The operative technique and the aesthetic and functional results after reconstruction with microtitanium augmentation mesh and dynamic mesh are discussed in detail.
Anatomical Study of the Lateral Orbital Flap
Dental Implants and Steinhiiuser's Floor-of-the-MouthPlasty for Improvement of Oral Function in Tumour Patients
Kusumoto K., Ogawa Y.
Kwakman J.M., Voorsmit R.A.C.A., Freihofer H.P.M.
Department of Plastic and Reconstructive Surgery, Kansai Medical University, Osaka, Japan
Department of Oral and Maxillofacial Surgery, Academic Hospital Nijmegen, Nijmegen, The Netherlands
A lateral orbital flap (LOF), as a subcutaneous pedicle flap (SCPF), has proved very beneficial for the reconstruction of the relatively small facial defect of peripalpebral and periorbital region. To clarify the vascularity of the region, the authors have conducted an angiographic study using cadavers. This study has found that the local specific vascularity is a centripetal pattern to the palpebral fissure, and there is a vascular arcade between zygomatico-orbital and zygomatico-facial arteries (ZOA-ZFA arcade). Further radiographic LOF inspection indicates that feeding is attributed to a mimic muscle in this axial pattern vascularity. Until now, the SCPF vascular support system has been thought to present a random pattern. However, this study has shown that when planed SCPFs, such as a LOF that has a local specific vascular direction, the arterial arcade or a cutaneous branch that passed through a mimic muscle can be used to supply them.
Introduction: Oral functions like speaking, chewing and swallowing are often reduced after ablative tumour surgery in mouth and oropharynx. For restoration of at least a part of these functions, stable dentures and satisfactory mobility of the tongue are necessary. Dental implants can be used to achieve a stable denture. Preimplant surgery, however, is often needed to reduce the amount of bulky tissue when myocutaneous flaps have been used for reconstruction. Besides, mobility of the tongue should be adequate.
Results after Reconstruction of Craniofacial Defect with Microtitanium Augmentation Mesh and Dynamic Mesh
Kuttenberger J.J., Hardt N., Kessler P. Department of Oral and Maxillofacial Surgery, Kantonsspital Luzern, Luzern, Switzerland Different operative techniques are used for reconstruction of craniofacial defects: cranioplasty with autogenous bone (calvaria, rib, iliac crest), cranioplasty with allogenous bone (AAA-bone) or cranioplasty with alloplastic materials (titanium mesh, methacrylate). At the Department of Oral and Maxillofacial Surgery, Kantonsspital Luzern, 10 patients with defects in the craniofacial and orbito-ethmoidal region have been treated using titanium micromesh during the last 5 years. Two different mesh systems (microtitanium augmentation mesh, dynamic mesh) have been used for reconstruction in non load-bearing areas. In 4 patients the defects were caused by acute trauma with comminuted fractures and bone loss, 4 patients showed extensive contour defects after former craniotomies, in 2 patients extensive residual defects after previous osteomyelitis of the frontal bone had to be restored. The microtitanium augmentation mesh or dynamic mesh are used for reconstruction in the following indications: immediate reconstruction in the primary treatment of comminuted fractures with bone loss in non load-beating areas, treatment of extensive contour disturbances in combination with bone or cartilage grafts, and reconstruction of areas with high risk of infection. Advantages of this reconstructive technique are
Materials and Methods: Twelve patients have been treated for improvement of oral functions after tumour surgery between 1992-1995, with a mean follow-up of 11.6 months. A combination of reduction of bulky tissue, insertion of dental implants and Steinhfiuser's floor-of-the-mouthplasty for improvement of the mobility of the tongue will be presented. Results: All patients reported an improved tongue mobility. Of the 10 patients in whom the dental treatment is completed, 9 patients stated that they are able to chew food. One patient does not chew because he can only swallow liquids, however he states that his speaking has been improved. Two patients complained that the improvement was less than they expected, both patients have a partial anaesthesia of their tongue caused by the tumour surgery. In 2 patients an additional conventional lowering of the floor of the mouth was performed during abutment placement. Conclusion: From our results it may be stated that Steinh~iuser's floor-of-the-mouth-plasty with secondary epithelialization in combination with osseointegrated implants is a simple, reliable and effective method for improvement of oral function in tumour patients.
Evaluation of Blood Supply in Free-Flaps by a New Non-Invasive Technique
Lang M. 1, Kern R), Kiircher Ho 1, Rienmiiller R )
Departments of 1Maxillofacial Surgery and :General Radiological Diagnostics, Medical School, Universityof Graz, Graz, Austria Thorough and continuous monitoring (in particular systemic blood pressure, central venous pressure) is mandatory during the first 48 h after surgery. Early detection of disturbed perfusion in the graft is essential for timely revision surgery of the vessel connections. Graft perfusion was evaluated by an (EBCT) (electron beam computer tomography flow study of a single 6 mm slice (exposure 300 ms, interscan