Regeneration of Horizontal Bone Defect in Edentulous Maxilla Using the Allogenic Bone-Plate Shell Technique and a Composite Bone Graft-A Case Report.

An insufficient volume of the alveolar bone may prevent implants from being placed in the prosthetically optimal position. Complex restoration of bony structures is required to achieve long-term peri-implant bone stability and represents an adequate prosthetic solution. Background and Objectives: The shell technique has become a widespread and important method for guided bone regeneration in dentistry. Allogeneic bone materials appear to be the most similar substitution for autogenous bone transplants. However, there are few studies using cortical bone allografts in combination with a mix of autogenous and xenograft materials for the augmentation of horizontal ridge defects. This combination offers the advantage of reduced patient morbidity while adding adequate volume and contour to the alveolar ridge. Case report: The present case study aimed to clinically and radiographically evaluate the efficacy of allogenic cortical bone lamina combined with a composite bone graft in the augmentation of a horizontal bone defect in the edentulous maxilla during a 6-year follow-up period. Three CB CT scans taken before treatment, 6 months after the augmentation period/before implant placement, and after a 6-year follow-up period, were analyzed using stable referent points. After the 6 -year follow-up period, the average resorption rate was 21.65% on the augmented buccal side, with no implant exposure being observed. Conclusions: The bone shell technique used in conjunction with allogenic bone plates combined with autogenous bone, xenografts, and collagen membranes is an effective technique to manage horizontal ridge defects.

Characterization of immunologically detectable T-cell sensitization, Immunohistochemical detection of pro-inflammatory cytokines, and clinical parameters of patients after allogeneic intraoral bone grafting procedures: a prospective randomized controlled clinical trial in humans.

BACKGROUND: The null hypotheses were tested that intraoral bone augmentation using two different allogeneic materials has no impact on the patient's blood levels of material-specific lymphocytes and on the immunohistochemical detection of pro-inflammatory cytokines IL-1α, IL1ß and TNF-α and T-cell markers CD4, CD8 in biopsies of the test groups. METHODS: In this prospective RCT, 60 systemically healthy participants were randomly assigned to two allogeneic test groups (1: Maxgraft®, freeze-dried, multiple donors, and 2: Puros®, solvent-dehydrated, single donor) and an autologous control group (10 patients). Plasma samples were collected pre-(T1) and postoperatively (2 weeks (T2) and 4 months (T3)). The Lymphocyte Transformation Test (LTT) was used for analyzing levels of transformed lymphocytes for type IV immune reactions by 3H-thymidine activity. Bone biopsies were harvested at T3 and immunohistochemically analyzed for IL-1α, IL1ß, TNF-α, CD4, CD8 and correlated with the immunological and clinical findings. RESULTS: A statistically significant difference between the tested materials was observed for LTT measurements at T3 (p = 0.033). Furthermore, three groups were identified: Group A (LTT negative T1-T3, n = 48), group B (LTT positive T1-T3, n = 7), group C (developing positive LTT at T2, n = 5). A highly significant elevation of IL-1α, IL1ß, TNF-α in patients of group C (p = 0.0001) and a significant elevation of CD4+ cells in patients of group B (p = 0.005) was shown. CONCLUSION: Our data show that following allogeneic bone grafting, local and systemic immunological reactions can be detected in some patients. These findings were statistically significant for the timepoint T3 between the tested materials as well as for the groups B and C correlated with group A for both tested materials. Therefore, the null hypotheses were rejected. A preoperative compatibility test for allogeneic materials in order to improve patient safety and the predictability of these materials would be desirable. TRIAL REGISTRATION: Ethical commission of the Ärztekammer Hamburg, Germany (PV5211) as well as by the German Registry of Clinical Studies (DRKS00013010) on 30/07/2018 ( http://apps.who.int/trialsearch/ ).

A comparison of three bone graft struts for interbody fusion using a posterior approach for lower lumbar spinal tuberculosis in adults: a midterm follow-up study.

BACKGROUND: This retrospective observational study was conducted to compare midterm outcomes of three bone graft struts for interbody fusion using a posterior approach in adults with lower lumbar spinal tuberculosis. METHODS: A total of 126 lower lumbar spinal tuberculosis patients were treated by one-stage posterior debridement, interbody fusion, and instrumentation. Forty-one patients (group A) were treated with autogenous bone graft for interbody fusion, 45 patients (group B) were treated with allogeneic bone grafting, and the remaining 40 (group C) patients were treated with titanium mesh cage. In addition, clinical and radiographic data were gathered and analyzed. RESULTS: At the final follow-up, all patients were completely cured. The operation period and intraoperative blood loss for groups B and C were significantly less than in group A (P = 0.000). Post-operation, neurological performance and quality of life were remarkably improved at the final follow-up. The preoperative lordosis angles of three groups were significantly improved, as evidenced by the values immediately after the operation or those at the final follow-up. The correction loss of the group C was lower than those of groups A and B (P = 0.000). All the patients obtained bone graft fusion, the fusion period of group B was longer than that of the other two groups (P = 0.000). No significant differences among the three groups in adjacent segment degeneration rates were found at the last visit (P = 0.922). CONCLUSIONS: This midterm follow-up study established that one-stage posterior debridement, interbody fusion, and instrumentation, combined with medical therapy, can effectively treat lower lumbar spinal tuberculosis. In addition, the intervertebral titanium mesh cage bone graft can provide better outcomes with regard to maintaining lordosis and preventing collapse.

A 3-year prospective randomized clinical trial of alveolar bone crest response and clinical parameters through 1, 2, and 3 years of clinical function of implants placed 4 months after alveolar ridge preservation using two different allogeneic bone-grafting materials.

PURPOSE: The aim of this study was to longitudinally evaluate changes in alveolar bone crest (ABC) levels and differences in resorption rates (RR) between the tested grafting materials following alveolar ridge preservation (ARP) after tooth extraction after 1, 2, and 3 years (T1-T8) of clinical function. METHODS: Patients were randomly assigned to two different bone allografts (group 1 maxgraft®, group 2 Puros®) for ARP. Non-restorable teeth were minimal traumatically extracted. Sockets were augmented with the tested materials and covered with a pericardium membrane. After 4 months of healing, 36 implants were placed and sites were clinically and radiographically monitored in the mesial (ABC-M), the distal (ABC-D, T1-T8), the bucco-lingual (ABC-BL), buccal (ABC-B) and oral (ABC-O) aspect (T1-T4). RESULTS: Changes in (ABC-M), (ABC-D), (ABC-BL), (ABC-B), and (ABC-O) levels showed statistically highly significant differences between T1 and T2 for both bone allografts (p < 0.001). Changes at the ABC-M and ABC-BL levels between T2 and T3 of group 1 showed a statistically significant difference (p < 0.001). Both groups achieved and maintained increased ABC levels without statistically significant differences throughout the monitoring periods of 1-3 years (T6-T8) of clinical function. No failures or adverse events were observed. CONCLUSIONS: To the best of our knowledge, this study is within its limitations the first study to directly compare ABC-changes and differences in RR of two different allogeneic grafting materials for a period of 3 years after ARP. It was demonstrated to be, despite significant differences in RR, a successful method of preserving increased ABC levels through 1, 2, and 3 years of clinical function. Trial registration DRKS00013010, registered 07/30/2018, http://apps.who.int/trialsearch.

Allogeneic Bone Application in Association with Platelet-Rich Plasma for Alveolar Bone Grafting of Cleft Palate Defects.

AIM: The aim of this study is to compare allogeneic bone grafts associated with platelet-rich plasma (ALBGs-PRP) to autogenous bone grafts (ATBGs) for alveolar reconstructions in patients with cleft lip and palate (CLP). MATERIALS AND METHODS: The Maxillofacial Surgery Service of the Comprehensive Care Center for CLP (CCCLP) in Curitiba (Paraná, Brazil). PATIENTS: Thirty out of 46 patients with 8-12 years of age and pre- or trans-foramen unilateral clefts were operated by the same surgeon. Groups were selected randomly after coin-toss for the first surgery to be ALBG-PRP. INTERVENTIONS: Pre- and post-surgery cleft defect severity was registered by a score system using superimposed digitalized peri-apical radiographs. The hypothesis indicated ABG-PRP to be similar to the ABG was proved. RESULTS: There was no statistically significant difference (P < 0.05) in bone augmentation for the ABG-PRP group (79.88%) when compared to the ABG group (79.9%). CONCLUSION: ABG-PRP is indicated as a successful treatment modality to reduce the need for additional donor sites and reduce morbidity and hospital stay.

Volumetric Changes of a Customized Allogeneic Bone Block Measured by Two Image Matching Tools: Introduction of a Novel Assessment Technique for Graft Resorption.

OBJECTIVE: The purpose of this case report was to present a method for the assessment of volumetric changes of bone blocks during healing and demonstrate its practicability by analysing the resorption of a pre-shaped allogeneic bone block used for the reconstruction of a complex maxillary defect. MATERIALS AND METHODS: CBCT-scans of a 19-year-old male treated with an allogeneic bone block were recorded pre-OP, post-OP, and following six months of healing. Graft shrinkage was assessed via two image matching tools, namely coDiagnostiX® and Slicer. A biopsy specimen was harvested along the implant canal at the time of implantation. RESULTS: The osseous defect was successfully restored and advanced graft remodelling was found upon re-entry as confirmed by the histomorphometric and histologic analysis. The initial volumes of the graft determined via coDiagnostiX® and Slicer were 0.373 mL and 0.370 mL., respectively, while graft resorption after six months of healing was 0.011 mL (3.00%) and 0.016 mL (4.33%). CONCLUSIONS: The avoidance of bone harvesting and reduction of invasiveness display an important issue in dentoalveolar restorations. However, before grafting materials can be considered a safe alternative, understanding their clinical performance, especially resorption stability, is pivotal. The present case report demonstrates a limited resorption of the allogeneic bone block and further emphasizes the practicability of determining bone resorption by the here introduced method. As our investigation comprises solely one subject, the results should be considered with care and substantiated by further studies.

Prótese e implante sobre enxerto alógeno: análise histológica e acompanhamento clínico: radiográfico por 8 anos / Prosthesis and implant on allogenic graft: histological analysis and clinical: radiographic follow-up for 8 years

Este relato de caso clínico tem como objetivo descrever a utilização de osso alógeno na reconstrução de maxila atrófica para posterior reabilitação com prótese fixa metalocerâmica sobre implantes, fazer uma análise histológica do tecido ósseo enxertado e descrever o acompanhamento clínico e radiográfico por 8 anos. Uma paciente de 54 anos, com edentulismo parcial e atrofia moderada-a-severa na maxila, apresentou-se para tratamento demonstrando muito interesse em receber prótese sobre implantes. Após exame clínico e radiográfico, foi realizada montagem dos modelos de estudo em ASA para enceramento diagnóstico e obtenção de um guia multifuncional (tomográfico/ cirúrgico). A tomografia indicou a necessidade de reconstrução óssea maxilar. Procedeuse então à aposição de blocos de osso alógeno para aumento horizontal nas regiões anterior e posterior da maxila. Um dos blocos foi triturado e utilizado para levantamento do assoalho do seio maxilar no lado esquerdo. Dez meses depois, uma nova tomografia foi solicitada, utilizando o mesmo guia inicial, e os implantes instalados, utilizando o guia multifuncional como guia cirúrgico. Neste momento, material ósseo foi coletado na interface osso enxertado/osso nativo com uma broca trefina. Os resultados histológicos demonstraram viabilidade das células ósseas no enxerto, além da presença de vasos sanguíneos. Após o tempo necessário para osseointegração, procedeu-se com tratamento protético. Nenhuma complicação foi relatada até oito anos de controle. A sequência de tratamento proposta forneceu bons resultados estéticos e funcionais. Concluiu-se, então, que o emprego de osso alógeno é uma alternativa viável para a reconstrução de rebordos alveolares severamente reabsorvidos(AU)

This clinical case report aims to describe the use of allogeneic bone in the atrophic maxilla reconstruction for subsequent rehabilitation with a fixed metal-ceramic prosthesis on implants; to perform a histological analysis of the grafted bone tissue; and to describe the clinical and radiographic monitoring for 8 years. A 54-year-old patient, with partial edentulism and moderate-to-severe atrophy in the maxilla showed great interest in receiving implant prostheses. After c linical and radiographic examination, the ASA study models were assembled for diagnostic waxing and a multifunctional guide (tomographic / surgical) was obtained. Tomography indicated the need for maxillary bone reconstruction. Allogeneic bone blocks were then placed for horizontal enlargement in the anterior and posterior regions of the maxilla. One of the blocks was crushed and used to lift the floor of the maxillary sinus on the left side. Ten months later, a new tomography was requested, using the same initial guide, and the implants installed, using the multifunctional guide as a surgical guide. At this time, bone material was collected at the grafted bone / native bone interface with a trephine drill. Histological results demonstrated viability of bone cells in the graft, besides the presence of blood vessels. After the necessary time for osseointegration, a prosthetic treatment was performed. No complications were reported up to eight years of control. The propose treatment sequence provided good aesthetic and functional results. It was concluded, then, that the use of allogeneic bone is a viable alternative for the reconstruction of severely reabsorbed alveolar edges(AU)

Allogeneic cortical struts and bone granules for challenging alveolar reconstructions: An innovative approach toward an established technique.

OBJECTIVE: The shell technique is a well-established procedure for GBR with which extensive osseous defects can be predictably restored by using cortical bone struts harvested from various intraoral aspects. Recent publications have demonstrated comparable results for autologous and allogeneic bone grafts, whereas the evidence on allogeneic cortical struts remains limited. CLINICAL CONSIDERATIONS: In this case series, we demonstrate the regeneration of five complex alveolar bone defects in four patients with subsequent insertion of fixed dental implants. In all cases, cortical struts made from human donor bone were applied in combination with allogeneic bone granules and collagen membranes. CONCLUSIONS: Similar to autologous cortical shells, the allogeneic struts functioned by creating an immobile container with which the osseous defects in all patients could be successfully restored, enabling placement of dental implants in accordance with the treatment plan. Even when the containers were solely filled with allogeneic granules, vascularized healthy tissue was present at re-entry, demonstrating the vast potential of these materials for applications in dentistry. CLINICAL SIGNIFICANCE: Especially when it comes to regeneration of complex alveolar bone defects, autologous bone grafts are often outlined as the only treatment modality. Here we show that innovative biomaterials like allogeneic bone grafts hold the potential to mimic the functions of autologous bone transplants and provide excellent clinical results without the requirement of a second surgical side for bone harvesting and no risk of donor-site morbidity.

Allogenic Bone Graft Enriched by Periosteal Stem Cell and Growth Factors for Osteogenesis in Critical Size Bone Defect in Rabbit Model: Histopathological and Radiological Evaluation.

BACKGROUND & OBJECTIVE: This study aimed to investigate the effect of decellularized allogeneic bone graft enriched by periosteal stem cells (PSCs) and growth factors on the bone repair process in a rabbit model, which could be used in many orthopedic procedures. METHODS: In this experimental study, a critical size defect (CSD) (10 mm) was created in the radial diaphysis of 40 rabbits. In group A, the defect was left intact with no medical intervention. In group B, the defect was filled by a decellularized bone graft. In group C, the defect was implanted by a decellularized bone graft enriched with platelet growth factors. In group D, the defect was treated by a decellularized bone graft seeded by periosteal mesenchymal stem cells (MSCs). Also, in group E, the defect was filled by a decellularized bone graft enriched with platelet growth factors and periosteal MSCs. Radiological evaluation was done on the first day and then in the second, fourth, and eighth weeks after the operation. The specimens were harvested on the 28th and 56th postoperative days and evaluated for histopathological criteria. RESULTS: The radiologic and microscopic analysis of the healing process in bone defects of the treated groups (C, D, and E) revealed more advanced repair criteria than those of groups A and B significantly (P<0.05). CONCLUSION: Based on this study, it appears that implantation of concentrated PSCs in combination with growth factors and allogeneic cortical bone graft is an effective therapy for the repair of large bone defects.

[Management principle and clinical suggestions of osteotomy gap of opening wedge high tibial osteotomy].

OBJECTIVE: To summarize the management principle and clinical suggestions of the osteotomy gap of opening wedge high tibial osteotomy (OWHTO). METHODS: The related literature of the osteotomy gap of OWHTO in recent years was reviewed, summarized, and analyzed. RESULTS: Delayed union and non-union of the osteotomy gap are main complications of OWHTO. Tomofix plate, as locking steel plate, has the characteristics of angular stability and can better maintain the stability of the osteotomy gap, promote bone healing, and avoid loss of correction. There are some treatment options for the osteotomy gap site, such as, without bone, autologous bone graft, allogeneic bone graft, bone substitute materials graft, and augment factor graft to enhance bone healing. When the osteotomy gap is less than 10 mm, it achieves a good outcome without bone graft. For the obesity, lateral hinge fracture, large osteotomy gap, or correction angle more than 10°, the bone graft should be considered. In cases whose osteotomy gap is nonunion or delayed union, the autologous bone graft is still the gold standard. When the osteotomy gap repaired with the allogeneic bone graft, it is better to choose fragmented cancellous or wedge-shaped cancellous bone, combining with the locking plate technology, also can achieve better bone union. The bone substitute material of calcium-phosphorus is used in the osteotomy gap, which has the characteristics of excellent bone conduction, good biocompatibility, and resorption, combining with the locking plate technology, which can also achieve better bone union in the osteotomy gap. The augment factors enhance the bone healing of the osteotomy gap of OWHTO is still questionable. The bone union of the osteotomy gap is also related to the size of the osteotomy gap and whether the lateral hinge is broken or not. CONCLUSION: No matter what type of materials for the osteotomy gap, OWHTO can improve the function and relieve pain for knee osteoarthritis. More randomized controlled trials are needed to provide evidence for clinical decision to determine which treatment option is better for the osteotomy gap of OWHTO.

Management principle and clinical suggestions of osteotomy gap of opening wedge high tibial osteotomy / 中国修复重建外科杂志

Objective: To summarize the management principle and clinical suggestions of the osteotomy gap of opening wedge high tibial osteotomy (OWHTO). Methods: The related literature of the osteotomy gap of OWHTO in recent years was reviewed, summarized, and analyzed. Results: Delayed union and non-union of the osteotomy gap are main complications of OWHTO. Tomofix plate, as locking steel plate, has the characteristics of angular stability and can better maintain the stability of the osteotomy gap, promote bone healing, and avoid loss of correction. There are some treatment options for the osteotomy gap site, such as, without bone, autologous bone graft, allogeneic bone graft, bone substitute materials graft, and augment factor graft to enhance bone healing. When the osteotomy gap is less than 10 mm, it achieves a good outcome without bone graft. For the obesity, lateral hinge fracture, large osteotomy gap, or correction angle more than 10°, the bone graft should be considered. In cases whose osteotomy gap is nonunion or delayed union, the autologous bone graft is still the gold standard. When the osteotomy gap repaired with the allogeneic bone graft, it is better to choose fragmented cancellous or wedge-shaped cancellous bone, combining with the locking plate technology, also can achieve better bone union. The bone substitute material of calcium-phosphorus is used in the osteotomy gap, which has the characteristics of excellent bone conduction, good biocompatibility, and resorption, combining with the locking plate technology, which can also achieve better bone union in the osteotomy gap. The augment factors enhance the bone healing of the osteotomy gap of OWHTO is still questionable. The bone union of the osteotomy gap is also related to the size of the osteotomy gap and whether the lateral hinge is broken or not. Conclusion: No matter what type of materials for the osteotomy gap, OWHTO can improve the function and relieve pain for knee osteoarthritis. More randomized controlled trials are needed to provide evidence for clinical decision to determine which treatment option is better for the osteotomy gap of OWHTO.

Minimum 5-Year Follow-Up Outcomes for Comparison Between Titanium Mesh Cage and Allogeneic Bone Graft to Reconstruct Anterior Column Through Posterior Approach for the Surgical treatment of Thoracolumbar Spinal Tuberculosis with Kyphosis.

OBJECTIVE: We aimed to compare the clinical efficacy of titanium mesh cage with that of allogeneic bone graft to reconstruct the anterior column through posterior approach for the surgical management of patients with thoracolumbar spinal tuberculosis with kyphosis. METHODS: From January 2011 to March 2013, 57 patients with single-segment or two-segments thoracolumbar spinal tuberculosis with kyphosis were treated by debridement, interbody graft, posterior instrumentation, and fusion via a posterior-only procedure. Twenty-four patients in group A were treated with allogeneic bone graft to reconstruct the anterior column, whereas 33 patients in group B were treated with titanium mesh cage. The clinical efficacy was evaluated by visual analog scale (VAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), neurologic function recovery, kyphotic Cobb angle, and postoperative complications. RESULTS: The mean follow-up was 72.4 months. Neurologic function was significantly improved after surgery in all cases. There were significant differences of VAS, ESR, and CRP between preoperation and postoperation at the final follow-up, with no significant difference between the two groups. The kyphotic Cobb correction was significantly improved when compared with those in preoperation, but there was no significant difference between the two groups. One patient in group A with two segments involved experienced graft fracture. He had anterior bone graft with titanium mesh cage. CONCLUSIONS: Minimum 5-year follow-up outcomes showed that one-stage posterior focus debridement, interbody graft using titanium mesh cages, posterior instrumentation, and fusion is an effective treatment for patients with thoracolumbar spinal tuberculosis accompanied by kyphosis. It may obtain better clinical efficacy than allogeneic bone graft for treating two-segments thoracolumbar spinal tuberculosis.

The Fate of Allogeneic Femoral Head Bone Grafts Using Varus-Valgus Constrained Total Knee Arthroplasty in Neuropathic Joints.

BACKGROUND: This study was conducted to assess the clinical and radiological results of total knee arthroplasty (TKA) with an allogeneic bone graft using varus-valgus constrained (VVC) prostheses in knees with severe bone defects and unstable neuropathy. METHODS: This study included 20 knees of 16 patients who underwent TKA between August 2001 and January 2006 due to unstable knees with severe bone destruction resulting from neuropathic arthritis. At the time of surgery, the mean age of the patients was 56 years. The mean length of the follow-up period was 10.7 years. A VVC condylar prosthesis was used with an allogeneic femoral head graft to reconstruct large bony defects. Clinical results were evaluated using the Hospital for Special Surgery, Knee Society function, and Western Ontario and McMaster Universities Osteoarthritis scores. Three-dimensional computed tomography was used to evaluate the radiological parameters, which included the tibiofemoral angle, loosening or osteolysis of components, and incorporation of the bone graft. RESULTS: The preoperative mean Hospital for Special Surgery, Knee Society function, and Western Ontario and McMaster Universities Osteoarthritis scores were 40.5, 43.2, and 78.3, respectively, and these scores improved to 86.0, 64.6, and 33.8, respectively at the final follow-up. The mean postoperative alignment was 6.1° of valgus angulation. One knee had instability, another knee had partial bony absorption, which was confirmed using 3-dimensional computed tomography, and the other 18 cases (90%) had satisfactory results. No cases experienced radiolucency, fracture, or infection. CONCLUSIONS: TKA with an allogeneic bone graft using a VVC prosthesis provides a viable option for the treatment of severe bone defects with soft-tissue insufficiency in neuropathic knee arthropathy.

Reconstruction of massive post-sternotomy defects with allogeneic bone graft: four-year results and experience using the method.

OBJECTIVES: Deep sternal wound infection poses a serious problem in cardiac surgery, with an up to 40% risk of mortality. Massive loss of sternum bone tissue and adjacent ribs results in major chest wall instability causing respiratory insufficiency and defects of soft tissue healing. Proposals for managing the situation have been published but the complexity of the issue precludes unequivocal resolution. Capitalizing on orthopaedic experience, we used allogeneic bone graft of sternum as a viable option. METHODS: We performed the transplantation of allogeneic bone graft in 10 patients. In 9 cases, an allograft of sternum was used and in 1 case an allograft of calva bone. After the primary cardiac surgery, a massive post-sternotomy defect of the chest wall had developed in all 10 patients. Vacuum wound drainage was applied in the treatment of all patients. To stabilize the transverse, titanium plates were used. Bone allograft was prepared by the official Tissue Centre. Crushed allogeneic spongy bone was applied to reinforce the line of contact of the graft and the edges of residual skeleton. In 9 cases, the soft tissue was closed by direct suture of mobilized pectoral flaps. In 1 case, V-Y transposition of pectoral flap was performed. RESULTS: In 6 cases, healing of the reconstructed chest wall occurred without further complications. In 3 cases, additional re-suture of the soft tissues and skin in the lower pole of the wound was necessary. Excellent chest wall stability along with the adjustment of respiratory insufficiency and good cosmetic effect was achieved in all cases. In 1 case, severe concomitant complications and no healing of the wound resulted in death within 6 months after the reconstruction. Median follow-up of all patients in the series was 14.1 months (1-36 months). In 4 patients, scintigraphy of the chest wall was performed. CONCLUSIONS: Our existing results show that allogeneic bone graft transplantation is a promising and easily applied method in the management of serious tissue loss in sternal dehiscence with favourable functional and cosmetic effects. The relatively small number of patients with such severe healing complications of sternotomy however puts critical limits to a more detailed comparison with other practices and evaluation of long-term results.

Case series and review of glandular odontogenic cyst with emphasis on treatment modalities.

Glandular odontogenic cyst is a newly determined jaw entity with aggressive behavior and a high rate of recurrence. There is histopathologic resemblance to other lesions of the jaw such as intraosseous mucoepidermoid carcinoma. Although enucleation and curettage are not the treatment of choice for this cystic lesion, they comprise the most common method. On the other hand, filling the defect is a controversial matter, especially in lesions with large size. We introduce 4 cases of GOC, of which 2 are cases of recurrence. We applied bone material substitutes in 3 of these cases with success.

Aloenxerto ósseo cortical desvitalizado com nitrogênio líquido - estudo experimental em ovelhas / Allogeneic bone graft devitalized in liquid nitrogen - sheep experimental study

O objetivo do trabalho foi avaliar a taxa e a forma de incorporação do aloenxerto ósseo cortical, submetido ao congelamento em nitrogênio líquido e inserido em tíbias de ovelhas. Foram utilizadas seis ovelhas clinicamente sadias que, aos pares, foram simultaneamente submetidas à ostectomia da diáfise tibial para a retirada de um segmento de 7cm que, após a desvitalização em nitrogênio líquido, foi implantado imediatamente no outro paciente e fixado com placa de compressão dinâmica (PCD) e parafusos corticais. Realizaram-se avaliações clínicas e radiográficas, imediatamente e a cada 30 dias, até o 180º dia de pós-operatório. Aos 180 dias, foi realizada eutanásia e coletou-se a tíbia direita para avaliação histopatológica. Aos 60 dias de pós-operatório, foi observado o uso funcional do membro operado, sendo a união radiográfica das interfaces proximal e distal verificadas, em média, aos 95 dias. Com isso, pôde-se concluir que o nitrogênio líquido é um método adequado de desvitalização de aloimplantes ósseos corticais de ovelhas, proporcionando altas taxas de incorporação óssea, em média, aos 95 dias de pós-operatório.

This study evaluated the allogeneic cortical bone graft incorporation after submission of the harvested fragment to a bout freezing in liquid nitrogen. Six adult sheep, clinically healthy, were submitted to a 7cm ostectomy of the tibial diaphysis. The fragment was submersed in a liquid nitrogen and implanted in another sheep missing a same-sized segment at the corresponding bone. Stabilization of the allograft in the host bone was accomplished by a dynamic compressive plate (DCP). Clinical and radiographic evaluations were performed in the immediate post-operatory period and in every 30 days for six months after surgery. The proximal and distal host-graft interfaces showed radiographic union at a mean postoperative time of 95 days in all the animals. The cortical bone allograft submitted to liquid nitrogen freezing provided adequate bone healing in the sheep model.

Immunohistochemical, tomographic, and histological study on onlay bone graft remodeling. Part III: allografts.

OBJECTIVE: In the last decades aroused the interest for bone tissue bank as an alternative to autogenous grafting, avoiding donor sites morbidity, surgical time, and costs reduction. The purpose of the study was to compare allografts (ALg) with autografts (AUg) using histology, immunochemistry, and tomographic analysis. MATERIAL AND METHODS: Fifty-six New Zealand White rabbits were submitted to surgical procedures. Twenty animals were donors and 36 were actually submitted to onlay grafting with ALg (experimental group) and AUg (control group) randomly placed bilaterally in the mandible. Six animals of each group were sacrificed at 3, 5, 7, 10, 20, and 60 postoperative days. Immunolabeling was accomplished with osteoprotegerin (OPG); receptor activator of nuclear factor-k ligand (RANKL); alkaline phosphatase (ALP); osteopontin (OPN); vascular endothelial growth factor (VEGF); tartrate-resistant acid phosphatase (TRAP); collagen type I (COL I); and osteocalcin (OC). Density and volume of the grafts was evaluated on tomography obtained at the surgery and sacrifice. RESULTS: The ALg and AUg exhibited similar patterns of density and volume throughout the experiments. The intra-group data showed statistical differences at days 7 and 60 in comparison with other time points (P = 0.001), in both groups. A slight graft expansion from fixation until day 20 (P = 0.532) was observed in the AUg group and then resorbed significantly at the day 60 (P = 0.015). ALg volume remained stable until day 7 and decreased at day 10 (P = 0.045). The light microscopy analysis showed more efficient incorporation of AUg onto the recipient bed if compared with the ALg group. The immunohistochemical labeling picked: at days 10 and 20 with OPG in the AUg group and at day 7 with TRAP in the ALg group (P = 0.001 and P = 0.002, respectively). CONCLUSIONS: ALg and AUg were not differing in patterns of volume and density during entire experiment. Histological data exhibit more efficient AUg incorporation into recipient bed compared with the ALg group. Immunohistochemistry outcomes demonstrated similar pattern for both ALg and AUg groups, except for an increasing resorption activity in the ALg group mediated by TRAP and in the AUg group by higher OPG labeling. However, this latter observation does not seem to influence clinical outcomes.