[Topographic study of the parietal region for the elaboration of revascularized cranium vault autograft]. / Izuchenie topografo-anatomicheskikh osobennostei temennoi oblasti pri razrabotke revaskulyariziruemogo kostno-fastsial'nogo temennogo autotransplantata.

OBJECTIVE: Topographic and blood vessel architecture study of the parietal area and distal regional pool of the superficial temporal artery (STA) to assess the possibility of revascularized cranium vault bone autograft formation. MATERIAL AND METHODS: For the topographic and anatomical study, 30 non-fixed corpses (17 male and 13 female) were selected, the average age of which was 59±5 years. In the anamnesis and catamnesis, there were no indications of trauma or other pathology of the head and neck, including vascular. STA was contrasted with a non-radiocontrast dye (brilliant green) with the introduction of the dye into the STA with preliminary ligation of the frontal branch of the STA. The area of blood supply to soft tissue and bone structures was studied. The angioarchitectonics of the parietal region was studied, the feeding vessel of the studied flap was identified. RESULTS: The obtained anatomical landmarks for the collection of CPFP flap make it possible to form a flap with high accuracy and minimize the morbidity of the donor area.

Exchange Cranioplasty Using Bioabsorbable Hydroxyapatite and Collagen Complex After Removal of an Extensive Frontal Bone Tumor in an Infant.

BACKGROUND: Forehead reconstruction is challenging. Reconstruction of the innate curvature of the forehead is difficult, and the forehead is an esthetically important part of the face. Although synthetic implants and autologous split bone grafts are useful, these cannot be used in infants. CASE DESCRIPTION: A 4-month-old girl was presented with a right frontal bone Ewing sarcoma. The tumor was removed, and the defect was reconstructed with an autologous contralateral parietal bone graft. The parietal bone defect was repaired with a bioabsorbable hydroxyapatite and collagen complex. Good reconstruction of the forehead and ossification of the donor site was achieved within 3 years after surgery. CONCLUSIONS: After removal of an extensive frontal bone tumor in an infant, exchange cranioplasty with an autograft using a bioabsorbable hydroxyapatite and collagen complex at the donor site yielded good results.

Effects of systemic erythropoietin treatment and heterogeneous xenograft in combination on bone regeneration of a critical-size defect in an experimental model.

The aim of the present study was to evaluate the effects of systemic EPO treatment alone or in combination with xenogenic bone graft augmentation on bone regeneration. Eleven adult male Sprague-Dawley rats were used in the present study. Rats were subjected to bilateral 5 mm critical size bone defects on the parietal bones under general anaesthesia. Right parietal bone defects were augmented with xenogenic bone graft and left parietal bone defect was left empty. Rats were randomly assigned for one of the two groups. One group of rats received (i) vehicle (n = 6) and other group received (ii) EPO (500IU kg/day) (n = 5). EPO treatment was continued for 28 days. Vascularization was analysed by immunohistochemical staining of CD31 (PECAM-1) and new bone formation was histomorphometrically evaluated. Xenogenic graft augmentation enhanced bone formation and vascularization significantly in either vehicle or EPO treated groups (p < 0.05). Histomorphometric results of angiogenesis was similar in the EPO treated group and the control group. However, angiogenesis was significantly higher in the combination of systemic EPO treatment with graft augmentation than graft augmentation alone (p < 0.01). Graft augmentation for treatment of critical size bone defects seems essential for proper bone healing. Results of the present study suggest that EPO potentiates the regenerative processes of augmented bone defects.

Validation of a simulator for cranial graft lift training: Face, content, and construct validity.

PURPOSE: Surgical skills can be improved through practical exercise. The use of specimens, human as well as animal, or live animals for surgical training is limited due to ethical concerns. Drawbacks of simulators are costs, fidelity and creditibility. Thus, simulators must be evaluated objectively to determine their validity before they can be used as teaching modalities. The aim of this study was to verify the face content and construct validity of a novel model-based simulator for lifting tabula externa transplants from the parietal skull. MATERIALS AND METHODS: Participants were invited to perform a tabula externa graft lift during a training session on the simulator. Task performance was analyzed with a standardized assessment tool evaluating realism and appropriateness. Specialist ratings were used to evaluate the performance of the participants. This was an exploratory study using a questionnaire, at Kepler University Hospital, Linz, Austria, a university hospital. According to their expertise in craniomaxillofacial surgery, 17 participants were subdivided into 3 groups: 8 novices, 7 experts and 2 raters. RESULTS: The face validity (realism) obtained an average score of 4.2 of a maximum of 5 points. Likewise, the content validity (appropriateness as a teaching modality) obtained an average score of 4.8 of maximum 5 points. No differences were found between experts and novices concerning the recorded surgery completion times (p = 0.418) or the sizes of the lifted grafts (p = 0.110). During the evaluation of task performance, the expert surgeons (46.9 ± 3.7) were graded significantly better than the novices (36.4 ± 8.5), which proved the construct validity of the simulator (p = 0.001). CONCLUSION: All investigated validities were confirmed and approved the simulator as a valid training tool for parietal graft lift.

Comparative finite element analysis of skull mechanical properties following parietal bone graft harvesting in adults.

INTRODUCTION: Parietal bone grafts are commonly used in cranio-maxillo-facial surgery. Both the outer and the internal layer of the calvarium can be harvested. The bone defect created by this harvesting may induce significant weakening of the skull that has not been extensively evaluated. Our aim was to evaluate the consequences of parietal bone graft harvesting on mechanical properties of the skull using a finite element analysis. METHODS: Finite elements models of the skull of 3 adult patients were created from CT scans. Parietal external and internal layer harvest models were created. Frontal, lateral, and parietal loading were modeled and von Mises stress distributions were compared. RESULTS: The maximal von Mises stress was higher for models of bone harvesting, both on the whole skull and at the harvested site. Maximal von Mises stress was even higher for models with internal layer defect. CONCLUSIONS: Harvesting parietal bone modifies the skull's mechanical strength and can increase the risk of skull fracture, mainly on the harvested site. Outer layer parietal graft harvesting is indicated. Graft harvesting located in the upper part of the parietal bone, close to the sagittal suture and with smooth internal edges and corners should limit the risk of fracture.

Reconstrução de calota craniana com prótese customizada de PMMA após craniectomias descompressivas / Skull reconstruction with PMMA customized prostheses after decompressive craniectomies

Introdução: A craniectomia descompressiva é uma cirurgia indicada no tratamento da hipertensão intracraniana em situações graves de traumas cranioencefálicos. Esta cirurgia confere uma aparência bizarra ao paciente, como se "parte da cabeça" houvesse sido retirada. Após a regressão do edema cerebral e quando o paciente reunir boas condições clínicas, a reconstrução craniana está indicada. A reconstrução da calota craniana poderá ser realizada com osso autólogo ou com materiais aloplásticos. Este estudo objetiva apresentar a experiência do autor com reconstruções de calota craniana utilizando próteses customizadas de PMMA. Métodos: Foram selecionados 14 pacientes submetidos à craniectomia descompressiva que, após serem liberados clinicamente pela Neurocirurgia, realizaram a reconstrução da calota craniana com próteses de PMMA customizadas por prototipagem entre os anos de 2014 e 2015 e com, no mínimo, 6 meses de pós-operatório. Sinais e sintomas de síndrome do Trefinado, tomografia computadorizada e aparência estética dos pacientes foram analisadas no pré e no 6º mês pós-operatório. Resultados: Todos os pacientes apresentaram melhora sintomatológica, melhora estética e expansão cerebral após a cirurgia. Conclusão: A reconstrução da calota craniana com prótese customizada de PMMA promoveu a melhora dos sinais e sintomas e da aparência estética de todos os 14 pacientes operados. A utilização de protótipos para customizar próteses cranianas facilitou a técnica operatória e possibilitou a recuperação de um contorno craniano muito próximo da normalidade.

Introduction: Decompressive craniectomy is indicated for the treatment of intracranial hypertension in cases of serious traumatic brain injury. This surgery results in a bizarre appearance, as if "part of the head" had been. After regression of cerebral edema and when the patient is in good clinical condition, the reconstruction of the skull is indicated. Reconstruction of the skull can be performed with autologous bone or with alloplastic materials. This study sought to present the experience of the author with skull reconstructions using custom PMMA prostheses. Methods: In between 2014 and 2015, fourteen patients with previous (longer than 6 months) decompressive craniectomies were selected after Neurosurgery medical clearance and underwent skull reconstruction with customized PMMA prototyped prostheses. Signs and symptoms of syndrome of the trephined, computed tomography, and aesthetic appearance of the patients were analyzed preoperatively and at 6 months after reconstruction. Results: All patients presented with improved symptomatology, aesthetic improvement and expansion of the brain after surgery. Conclusion: Reconstruction of the skull with customized prototyped PMMA prostheses improved the signs and symptoms and the aesthetic appearance in all 14 patients of this series. The use of prototypes to customize cranial prostheses facilitates the operative technique and enables patients to develop a nearly normal cranial contour.

Retrospective evaluation of 211 patients with maxillofacial reconstruction using parietal bone graft for implants insertion.

PURPOSE: For a century, autologous bone grafts have been used in maxillofacial reconstruction. The ideal bone harvest site and grafting procedure remains a point of contention in regards to obtaining optimal long-term results with sufficient bone quantity and density without serious complications. More recently, confronted with growing patient requests and biomaterials development, maxillofacial surgeons and dentists have been considering these issues as they relate to pre-implant surgery. This study sought to evaluate implant success rate and complications following pre-implant surgery with parietal bone grafting. MATERIALS AND METHODS: A retrospective study was carried out on patients who underwent maxillofacial reconstruction of different sites (symphysis, mandibular corpus, maxillary sinus and premaxilla) for the purpose of implant insertion. RESULTS: 311 procedures in 211 patients were included. The implant osseointegration rate was around 95%. Clinical follow-up ranged from 10 months to 11 years. A secondary procedure was performed in 6.1% of cases and we noted no serious complications at the harvest site. DISCUSSION: With good revascularization and osseointegration of the graft, the use of parietal bone leads to an implant success rate similar to that seen in the literature. Moreover, the use of this material results in few infections and low bone resorption provided there is strict immobilization of the graft and no tension on the soft tissue sutures. CONCLUSION: Parietal bone grafts technique possess the required qualities for the success of implant surgery, offering results at least as interesting as others using autogenous bone and with no serious complications on donor site.

Le Fort 1 osteotomy and calvarial bone grafting for severely resorbed maxillae.

INTRODUCTION: Long standing maxillary edentulism leads to alveolar ridge resorption which prevent implant placement and causes prosthetic malocclusion. The aim of the study was to assess vertical and transversal bone increase following Le Fort 1 osteotomy associated with calvarial bone grafting. MATERIALS AND METHODS: 66 patients who presented severely atrophic maxillae were treated with Le Fort 1 osteotomy with bone grafting from 2003 to 2014. Vertical and transversal bone level was measured preoperatively and 6 months post-operatively to calculate the alveolar ridge augmentation. Follow up ranged from 10 months to 11 years. RESULTS: The mean increase of bone height was 9.3 mm and the mean increase of bone width was 6 mm 417 endosseous implants were placed in the grafted maxilla. Mean endosseous implant length was of 10.7 mm at the first molar site (range: 8-16 mm). A total of 25 implants failed, the overall implant survival rate is of 94%. The definitive prosthetis was fixed in 65% of the patients and removable in 35% of the patients. DISCUSSION: Le Fort 1 osteotomy associated with calvarial bone grafting is the main treatment option able to offer fixed bridge and perfect class 1 occlusion in cases of severe maxillary atrophy.

[Posttraumatic enophthalmos correction by bone graft: Why the unpredictable results?]. / Correction de l'énophtalmie post-traumatique par greffe osseuse: pourquoi des résultats inconstants?

PURPOSE OF THE STUDY: Posttraumatic enophthalmos cause complex cosmetic problems to fix. In order to get better results, we wanted to calculate the volume of parietal bone graft needed to be put in place, know where to place it in orbit and study soft tissues' participation. PATIENTS AND METHOD: In a retrospective study, we have calculated on scanner the volume of bone and soft tissue as well as the volume and the location of the graft. We have compared, between two groups ("good result" and "insufficient result"), graft volumes, taking into account differences in bone's volume between the healthy and the traumatized orbit. A comparison of the locations of the graft was also made. We were trying to find out if these factors were involved in the quality of the result. RESULTS: Twenty-nine surgeries on 24 patients were analyzed. The average bone's volume of an orbit with enophthalmos was 24.76 cm(3) for 17.12 cm(3) of soft tissue. Retro-lens distance was the most reliable measurement method of enophthalmos (P=0.001). There was a trend to a more substantial over-correction in the group "good result". A significant increase (P=0.0008) of soft tissue volumes in the traumatized orbit was found. CONCLUSION: This last result is surprising. Many authors believe that there is a scar retraction of soft tissues. But Kronish et al. showed an increase of the fat density and connective tissue. This, together with the assumption of a weathering of the ligament suspension of the globe, may affect our aesthetic results. MRI, ultrasound and anatomopathological studies would allow a better understanding of the fat, muscle and ligament pathophysiologies of an orbit with enophthalmos.

Frontal sinus obliteration with autologous calvarial bone graft: indications and results.

Despite increasing advances in endonasal frontal sinus surgery, frontal sinus obliteration (FSO) is sometimes necessary after failure of other surgical techniques. This procedure has been reported with autologous tissue or synthetic material, but few studies have reported results with autologous calvarial bone graft. The aim of this study was to report our experience with osteoplastic FSO calvarial bone graft. A retrospective review was performed on 11 patients operated upon for FSO with autologous calvarial bone graft from 2005 to 2011. Obliteration was indicated for chronic symptomatic frontal sinusitis with nasofrontal duct stenosis in five cases of nasal polyposis with a history of endoscopic sinus surgery, two cases of frontal trauma, two of surgery for frontal inverted papilloma and two of chronic frontal purulent sinusitis. Ten patients had a history of one or two previous functional endoscopic sinus surgery (FESS) procedures. On outcome assessment, eight patients had no residual complaints after FSO and all patients showed improvement in symptoms. Frontal sinus obliteration with autologous calvarial bone graft showed low donor site morbidity and good aesthetic results. This procedure should be considered in severe frontal sinusitis after repeated FESS procedures have failed.

Cranial bone regeneration after cranioplasty using cryopreserved autogenous bone by a programmed freezer with a magnetic field in rats.

BACKGROUND: The purpose of this study was to develop a bone tissue bank using a programmed freezer with a magnetic field. Parietal bones were removed from rats and used for organ culture examination (non-cryopreserved, cryopreserved with a magnetic field (CAS) and cryopreserved without a magnetic field group). Next, other parietal bones were used for histological examination. The cryopreserved bones by a CAS freezer and dried bones were transplanted respectively. Control bones were replanted without cryopreservation. Animals were sacrificed at 4, 8, 12 and 24 weeks after surgery. After organ culture, the isolated osteoblasts from parietal bones which were cryopreserved by a CAS freezer can survive and proliferate as much as non-cryopreserved group. Histological examinations showed new bone formation in control and CAS group. These results suggest that bone tissue cryopreservation by CAS freezer can be successfully used for bone grafting which may be a novel option for regeneration medicine.

Demineralization of the contacting surfaces in autologous onlay bone grafts improves bone formation and bone consolidation.

BACKGROUND: Autologous bone grafts are usually well consolidated after 4 to 5 months but can be incompletely interlocked with the native bone. This study investigated the effect of acid demineralization of the graft-bed interface on graft consolidation. METHODS: Onlay bone grafts were performed on the calvaria of 36 guinea pigs. Half of the animals had the graft-bed contacting surfaces demineralized with 50% citric acid (pH 1.0) for 3 minutes (test group). The other half received no demineralization (control group). The bone grafts were immobilized by a resorbable membrane glued to the recipient bed with cyanoacrylate. After 7, 30, and 90 days, specimens (n = 6) were obtained for light microscopy. Data from qualitative analysis and computerized histomorphometry were statistically processed at a significance level of 5%. RESULTS: Osteogenesis was not seen at the interface after 7 days. After 30 days, the test group showed 34.39% ± 13.4% of the interface area filled with mineralized tissue, compared to 17.14% ± 8.6% in the control group (P = 0.026). After 90 days, the mean percentages of mineralized tissue at the interface in the test and control specimens were 54.00% ± 11.23% and 38.65% ± 7.76% (P = 0.041), respectively. Within groups, a higher percentage of the area filled with mineralized tissue was seen at 90 days compared to 30 days (P = 0.004 for control and 0.041 for test). CONCLUSIONS: Demineralization of the contacting surfaces between autologous bone graft and bone bed improved new bone formation and bone consolidation. These data need to be confirmed in humans.

Histometric analyses of cancellous and cortical interface in autogenous bone grafting.

Surgical procedures involving the rehabilitation of the maxillofacial region frequently require bone grafts; the aim of this research was to evaluate the interface between recipient and graft with cortical or cancellous contact. 6 adult beagle dogs with 15 kg weight were included in the study. Under general anesthesia, an 8 mm diameter block was obtained from parietal bone of each animal and was put on the frontal bone with a 12 mm 1.5 screws. Was used the lag screw technique from better contact between the recipient and graft. 3-week and 6-week euthanized period were chosen for histometric evaluation. Hematoxylin-eosin was used in a histologic routine technique and histomorphometry was realized with IMAGEJ software. T test was used for data analyses with p<0.05 for statistical significance. The result show some differences in descriptive histology but non statistical differences in the interface between cortical or cancellous bone at 3 or 6 week; as natural, after 6 week of surgery, bone integration was better and statistically superior to 3-week analyses. We conclude that integration of cortical or cancellous bone can be usefully without differences.

[Viability of the parietal bone autografts preserved in adipose tissue. Preliminary report of an experimental study in rats]. / Viabilidad del auto injerto de hueso parietal conservado en tejido adiposo. Informe preliminar de un estudio experimental en ratas.

INTRODUCTION: Decompressive craniectomy is an alternative in cases where there is increased intracranial pressure. Bone autografts are accepted as a method of reconstruction of the skull. The aim of this paper is to describe the macroscopic and radiological findings of autologous parietal bone in rats after storage in adipose tissue as a reservoir. METHODS: We used 20 Wistar rats which underwent a craniectomy. 4 groups were formed: group I, the bone flap fat remained for 14 days, group II, the flap remained for 21 days, in group III, for 28 days and in group IV for 35 days. They were euthanized 70 days after reattached. RESULTS: When removing the flap of subcutaneous fat, a high bright whitish microvasculature and presence in 11 of the flaps. Following 70 days of re-injertarse was found that 56.25% of the animals presented terraced edges, reflecting some consolidation in the radiological analysis 31.25% of cases showed areas of consolidation. Animals in group II and III findings showed more consolidation. CONCLUSIONS: The bone flap remained viable during their stay in adipose tissue. Fibrous tissue and neovasculature were important findings that reflect the proper process of bone healing. You need the histological studies complemented biomechanics, neurological and bioacoustics.

Effect of calvarial burring on resorption of onlay cranial bone graft.

Variable resorption occurs whenever calvarial bone graft is used for onlay cranioplasty. The recipient ectocortex may be burred to expose vessels and osteocytes to maximize healing. The purpose of this study was to determine whether abrading the recipient site improves the volume of onlay graft. The parietal bones of 17 rabbits were sectioned into split-thickness and full-thickness grafts. The right frontal cortex was abraded with a bur to punctate bleeding. Pairs of split-thickness (n = 48) or full-thickness (n = 20) grafts were onlayed to the burred right frontal bone and to the nonburred left frontal bone. Micro-computed tomography was used to determine graft volume immediately postoperatively and 16 weeks later. Histology, including tartrate-resistant acid phosphatase staining, was performed to quantify vascular channels and osteoclasts per high-power field 10 days postoperatively. Split-thickness graft volume decreased 58.0% when placed on the burred calvarial site, compared with grafts on the nonburred cortex (28.4%) (P = 0.01). Full-thickness grafts showed a similar trend: greater resorption (39.1%) when onlayed onto abraded calvaria compared with nonburred ectocortex (26.0%) (P = 0.11). Split-thickness graft orientation (cortical vs cancellous side in contact with the recipient site) did not affect resorption (P = 0.67). Onlay grafts placed on the burred recipient site had more vascular channels (11.8) and osteoclasts (5.7), compared with grafts over nonabraded cortex (3.4 and 4.2, respectively) (P < 0.05). Burring the recipient site cortex before onlay cranial bone grafting promotes resorption, possibly by increasing vascularization and osteoclastic activity. This technique cannot be recommended.

Mechanical characterization and optoelectronic measurement of parietal bone thickness before and after monocortical bone graft harvest: design and validation of a test protocol.

Parietal bone grafts are commonly used in craniomaxillofacial surgery. However, bone removal may weaken the parietal bone and lead to deleterious complications. The aim of our study was to design a test protocol for characterization of the impact resistance of parietal bone before and after monocortical bone graft harvest and to validate an optoelectronic measurement of parietal bone thickness. Twelve fresh human cadaver heads were used for the validation study. To evaluate impact resistance, we developed a pendulum Charpy impact testing machine. The impact force was gradually increased until failure (fracture) of the defined parietal bone area. According to the protocol, we measured the maximum absorbable energy or impact force to failure. With our test setup, measurement of the impact resistance of parietal bone was accurate to within 0.025 J. We defined a range of values and particularly a threshold value. The initial maximal impact must not to exceed 4 J. For more accuracy, we compared 5 nondestructive measurement methods using a surgical navigation system with optoelectronic tracking. We achieved an algorithm based on 2 methods that ensured a measurement resolution of 0.1 mm. Validation of this protocol will allow us to evaluate the loss of strength resulting from bone removal and the correlation between strength and thickness of the parietal bone.

Evaluation of skull strength following parietal bone graft harvest.

BACKGROUND: Parietal bone grafts are commonly used in craniomaxillofacial surgery. The primary aim of this study was to quantify the loss of strength following monocortical parietal bone graft harvest. The secondary aim was to establish a correlation between strength and thickness of calvaria. METHODS: Thirty fresh human cadaver heads (nonfrozen, unembalmed heads) were used for this study. Loss of strength was determined by comparing the maximum impact resistance of bone on the donor side versus the intact side, using a precalibrated pendulum Charpy impact testing machine. Thickness was measured using a surgical navigation system with optoelectronic tracking. RESULTS: Loss of strength at the donor site was 36 percent (p=0.0000000001) for a 40 percent loss of thickness. Although correlation between these two parameters is rather moderate (r=0.46), it is highly significant (p<0.0001). CONCLUSIONS: Although loss of strength is quite significant, serious complications at the donor site are rare. As shown in this study, these risks are nonnegligible. However, because of strong legal pressure, surgeons must carefully weigh the risks incurred by the patient against the expected benefits, whether immediate or deferred. Therefore, the patient should receive well-documented information before such monocortical parietal bone graft harvest is performed.

Cranioplasty for repair of a large bone defect with autologous and homologous bone in children.

Cranioplasty is a well-established reconstructive procedure for restoring craniocerebral protection and improving cosmetic defects. Most allograft materials are not suitable in pediatric patients owing to skull growth; thus, autologous bone is often preferred in the reconstruction of the pediatric skull because of its capacity to osseointegrate and grow with the pediatric skeleton. A 33-month-old boy with Ewing sarcoma of the right frontal bone underwent surgical treatment with tumor excision. The resected bone was reconstructed with full-thickness calvaria harvested from the right parietal region. The residual parietal gap was filled with homologous bone taken from the iliac wing. This reconstructive technique was chosen to guarantee normal development of the frontal region and tissue integration, while considering possible radiotherapy after the primary surgery.

Evolução comparativa das diferentes abordagens cirúrgicas na reconstrução da calota craniana / Comparative evolution of different surgical approaches on skull reconstruction

A cranioplastia tem como função a proteção cerebral e restauração da aparência pré-

-injúria. Adicionalmente, disfunções na fala e hemiparesia podem melhorar se o defeito for

extenso o suficiente para permitir que o escalpo transmita pressão sobre o cérebro. Defeitos

cranianos maiores que 2 a 3 cm devem ser considerados para a reconstrução. Objetivo:

correlacionar as características dos pacientes e dos defeitos cranianos tratados no Centro

de Cirurgia Crânio-Maxilofacial do INTO com a indicação do tipo de terapêutica cirúrgica

aplicada. Métodos: estudo retrospectivo dos pacientes operados entre Janeiro de 2008 e

Abril de 2010 para reconstrução de calota craniana realizado no Centro de Cirurgia Crânio-

Maxilofacial do Instituto Nacional de Traumatologia e Ortopedia. Resultados: Foram

analisados 11 pacientes, todos do sexo masculino, tendo o trauma como o fator etiológico

mais comum. Lesões menores que 50 cm2 foram reconstruídas com enxerto ósseo autólogo

de parietal, lesões de 50 a 77 cm2 foram reconstruídas com enxerto autólogo de parietal

bilateral, e lesões maiores que 77 cm2, com prótese customizada de biocerâmica. Conclusões:

O enxerto autólogo de parietal foi o método de escolha em reconstruções menores que

50 cm2 e em defeitos extensos maiores que 77 cm2 optou-se pela prótese customizada de

biocerâmica. Nos casos limítrofes de 50 a 77 cm2, pela dificuldade de obtenção da prótese,

foram utilizadas duas lâminas de parietal, prolongando o tempo cirúrgico, aumentando a

perda sanguínea e risco de injúria cerebral

Vascular endothelial growth factor and e-nitric oxide synthase-mediated regenerative response occurring upon autologous and heterologous bone grafts.

Bone regeneration procedures allow oral rehabilitation with dental implants also in edentulous ridges with severe bone atrophy. The integration of grafted materials with the host tissue can initiate regenerative, inflammatory and apoptotic response. Since molecular mechanisms exist at the basis of such response, the aim of this work is to investigate, by immunohistochemical analyses, the expression of proteins involved in the graft integration process, in parallel to clinical and histological modifications, occurring on sites treated with extraoral autologous bone graft deriving from the parietal region of the calvaria (eAB), intraoral autologous bone graft deriving from mandibular ramus (iAB) and heterologous bone graft from swine (hB) in human patients. In our study, the immunohistochemical expression of BSP, VEGF, eNOS in eAB samples was significantly higher (p < 0.05) compared to values recorded in iAB and hB samples. The inflammatory response, investigated by iNOS expression, was found lower in all autologous samples (eAB and iAB) compared to hB, at statistically significant values. Moreover, the expression of the pro-apoptotic molecule, Bax, resulted significantly lower (p < 0.05) in eAB than in iAB and hB samples. These values, together with the low number of apoptotic cells detected in autologous samples, suggest a good regenerative response when extraoral autologous bone graft is used in comparison to the response from the other grafts, and also suggest the use of calvaria graft as a predictable therapeutic procedure for repairing severe bone defects in oral and maxillofacial surgery, not only by clinical and biomechanical criteria, but also from a biomolecular aspect.