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The histopathologic effects of hydroxyapatite-collagen combination on short-term bone healing: An experimental study
114 Journal of Cranio-Maxillofacial Surgery been made of polyglycolide, polylactide, lactideglycolide copolymer, or polydioxanone. Poly-L-lactic acid (PLLA) is the material we choose because of its high initial strength. the appropriate modulus, the deformation behaviour, and the adequate stability throughout the process of bone healing with a rapid resorption without local or systemic undesired effects. Seven patients have been operated on using PLLA plates and screws, all affected by mandibular fractures. Three were females and 4 were males; age ranged from 17-54 years. Fractures involved symphysis (3 cases), angle (2 cases) and left body (2 cases). The patients were followed-up monthly by clinical examination, evaluating the palpability of the implant, the presence of signs of infection and the healing of the fracture. An echographic examination was performed every 3 months, and X-rays were taken after 1 and 6 months. Follow-up ranged from 3-12 months. All fractures healed well; there were no infections, malunions, nonunions. The echographic examination showed a rail-like image and a reduction of both thickness and length was revealed after 6 months. This preliminary experience with PLLA plates and screws encourages further studies, and gave us the stimulus toward the experimentation of new designs for this intriguing material. Poly-L-lacticacid is not only very easy to mould, but also can be drilled where it is needed, leaving the rest of the plate intact for the maximum strength. A new generation of PLLA plates and screw is coming, promising to be more user friendly than the old system, but some key points still need to be refined, in order to overcome the need for the tapping devices we had to use before inserting any screw, and to eliminate all other time-consuming factors characteristic of PLLA as of any new procedure.
Evolution of Fixation Methods in Oral and Maxillofacial Surgery
Tartaro S., Cozzolino A.
Department of Oral and Maxillofacial Surgery, Second University of Naples, Naples, Italy In the history of fixation methods, the introduction of rigid fixation by plates and screws was significant. In fact, the osteosynthesis by metallic wires, associated to intermaxillary fixation, did not assure a perfect and stable immobilization. The rigid fixation by external tools, as screws and pivots connected to a metallic bar, limited the patient's way of life. The technological evolution has contributed to better the therapeutic approach by the use of nitinol graffes and poly-DLlactic acid plates. The nitinol memory-shaped graffes allows programmable tightness, shorter surgical times, as well as stability. The poly-DL-lactic acid plates are more suitable for most anatomical conditions and are completely degradable.
The Histopathologic Effects of Hydroxyapatite-Collagen Combination on Short-Term Bone Healing: An Experimental Study
Tasman U.l, K~seoglu 0.1, Dagdeviren A. ~, Kendir B. 2
1Department of Oral Surgery, Faculty of Dentistry, Hacettepe University, Ankara, Turkey 2Department of Histology, Faculty of Medicine, Hacettepe University, Ankara, Turkey In our experimental study, the effects of hydroxyapatite, collagen matrix and combination of these two materials on
short term bone healing were histopathologically compared. Thirty guinea pigs from both sexes were selected and two experimental defects were created on both sides of the mandible and filled with hydroxyapatite, collagen matrix and combination of these two materials. One defect was left empty as control group. The histopathologic examinations were performed on 7th, 14th and 21st days. The results of our experimental study showed that the whole materials were biocompatible with the soft and hard tissues and aggravated the bone healing capacity. When compared, hydroxyapatite-collagen combination effected the bone reparation phase better than the other alloplastic materials.
Skull Base Chordomas involving Paranasal Sinuses, Orbits, Anterior Cranial Fossa
Tcherekaev EA., Makhmudov U.B., Shimansky EN., Edneva EN., Usachev D. E
Burdenko NeurosurgicaI Institute, Moscow, Russia Chordomas are rare, slow-growing, locally invasive tumours arising from remnants of embryogenic notochord. Ninety per cent of chordomas arise in the sacrococcygeal or basisphenoid regions. They represent less then 1% of all intracranial tumours (Poppen and King, 1952). From 1993 to 1995, 4 patients with expansive skull base chordomas, involving paranasal sinuses, both orbits and anterior cranial fossa have been operated on. In all patients the bilateral proptosis, epistaxis, nasal obstruction were the main symptoms. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed the expansive extradural, infiltrative tumour of the anterior cranial fossa, both orbits, sphenoidal, ethmoidal, medial parts of both maxillary sinuses with destruction of the bone of the anterior cranial fossa. The patients were operated on with use of modification of craniofacial approach. In all cases the tumour was extradural without signs of infiltration of dura. The skull base defect closed with the use of the flaps of periosteum and abdominal fat. Lumbar drainage was necessary during the time of surgery and 5 days after surgery. Postoperative CT revealed total removal of tumour. One patient had relapse of chordoma 1 year after surgery. She was reoperated and postoperative radiotherapy 60 Gy was performed. The peculiarities of surgical technique are discussed.
Recombinant Human Osteogenic Protein 1 (rhBMP 7) in the Rat Mandibular Augmentation Model using Different Carrier Materials
Terheyden H.1, Jepsen S.2, Vogeler S.2, Tucker M. 3, Rueger D. C.3
Departments of 1Oral and Maxillofacial Surgery and 2Conservative Dentistry and Periodontolgy, University of Kiel, Kiel, Germany 3Creative Biomolecules, Hopkinton, Massachusetts, USA Bone morphogenetic proteins (BMP) can induce heterotopic bone formation and therefore have a potential clinical benefit in maxillofacial surgery. The objective of this study was to evaluate the effect of recombinant human osteogenic protein 1 (rhOP1 = rhBMP7) in different carriers on mandibular augmentation. In 30 male Wistar rats, bilaterally subperiostal pouches were created between the lateral aspect of the mandible and the masseteric muscle. Into the pouches 0.25 cc of 6 different materials were inserted
Evolution of Fixation Methods in Oral and Maxillofacial Surgery
Tartaro S., Cozzolino A.
Department of Oral and Maxillofacial Surgery, Second University of Naples, Naples, Italy In the history of fixation methods, the introduction of rigid fixation by plates and screws was significant. In fact, the osteosynthesis by metallic wires, associated to intermaxillary fixation, did not assure a perfect and stable immobilization. The rigid fixation by external tools, as screws and pivots connected to a metallic bar, limited the patient's way of life. The technological evolution has contributed to better the therapeutic approach by the use of nitinol graffes and poly-DLlactic acid plates. The nitinol memory-shaped graffes allows programmable tightness, shorter surgical times, as well as stability. The poly-DL-lactic acid plates are more suitable for most anatomical conditions and are completely degradable.
The Histopathologic Effects of Hydroxyapatite-Collagen Combination on Short-Term Bone Healing: An Experimental Study
Tasman U.l, K~seoglu 0.1, Dagdeviren A. ~, Kendir B. 2
1Department of Oral Surgery, Faculty of Dentistry, Hacettepe University, Ankara, Turkey 2Department of Histology, Faculty of Medicine, Hacettepe University, Ankara, Turkey In our experimental study, the effects of hydroxyapatite, collagen matrix and combination of these two materials on
short term bone healing were histopathologically compared. Thirty guinea pigs from both sexes were selected and two experimental defects were created on both sides of the mandible and filled with hydroxyapatite, collagen matrix and combination of these two materials. One defect was left empty as control group. The histopathologic examinations were performed on 7th, 14th and 21st days. The results of our experimental study showed that the whole materials were biocompatible with the soft and hard tissues and aggravated the bone healing capacity. When compared, hydroxyapatite-collagen combination effected the bone reparation phase better than the other alloplastic materials.
Skull Base Chordomas involving Paranasal Sinuses, Orbits, Anterior Cranial Fossa
Tcherekaev EA., Makhmudov U.B., Shimansky EN., Edneva EN., Usachev D. E
Burdenko NeurosurgicaI Institute, Moscow, Russia Chordomas are rare, slow-growing, locally invasive tumours arising from remnants of embryogenic notochord. Ninety per cent of chordomas arise in the sacrococcygeal or basisphenoid regions. They represent less then 1% of all intracranial tumours (Poppen and King, 1952). From 1993 to 1995, 4 patients with expansive skull base chordomas, involving paranasal sinuses, both orbits and anterior cranial fossa have been operated on. In all patients the bilateral proptosis, epistaxis, nasal obstruction were the main symptoms. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed the expansive extradural, infiltrative tumour of the anterior cranial fossa, both orbits, sphenoidal, ethmoidal, medial parts of both maxillary sinuses with destruction of the bone of the anterior cranial fossa. The patients were operated on with use of modification of craniofacial approach. In all cases the tumour was extradural without signs of infiltration of dura. The skull base defect closed with the use of the flaps of periosteum and abdominal fat. Lumbar drainage was necessary during the time of surgery and 5 days after surgery. Postoperative CT revealed total removal of tumour. One patient had relapse of chordoma 1 year after surgery. She was reoperated and postoperative radiotherapy 60 Gy was performed. The peculiarities of surgical technique are discussed.
Recombinant Human Osteogenic Protein 1 (rhBMP 7) in the Rat Mandibular Augmentation Model using Different Carrier Materials
Terheyden H.1, Jepsen S.2, Vogeler S.2, Tucker M. 3, Rueger D. C.3
Departments of 1Oral and Maxillofacial Surgery and 2Conservative Dentistry and Periodontolgy, University of Kiel, Kiel, Germany 3Creative Biomolecules, Hopkinton, Massachusetts, USA Bone morphogenetic proteins (BMP) can induce heterotopic bone formation and therefore have a potential clinical benefit in maxillofacial surgery. The objective of this study was to evaluate the effect of recombinant human osteogenic protein 1 (rhOP1 = rhBMP7) in different carriers on mandibular augmentation. In 30 male Wistar rats, bilaterally subperiostal pouches were created between the lateral aspect of the mandible and the masseteric muscle. Into the pouches 0.25 cc of 6 different materials were inserted