CEComparison of allogeneic and autogenous bone grafts for augmentation of alveolar ridge defects-A 12-month retrospective radiographic evaluation.
ABSTRACT: OBJECTIVES:The aim of this study was to compare three-dimensional alterations following the use of autogenous versus allogeneic onlay grafts for augmentation at single tooth defects. MATERIALS AND METHODS:Alveolar bone width at specific implant sites were assessed using sagittal and cross-sectional CBCT images prior grafting and at three subsequent time points. Twenty-one patients received autogenous bone blocks harvested from the retromolar region and another 21 patients received freeze-dried cancellous allogeneic bone blocks. RESULTS:The vertical and horizontal dimensions did not significantly differ between autogenous and allogeneic bone grafts at any time point. In addition, there were no statistically significant differences in graft remodeling rates between autogenous (mean shrinkage rate after 12 months: 12.5% ± 7.8%) and allogeneic onlay grafts (mean shrinkage rate after 12 months: 14.4% ± 9.8%). CONCLUSIONS:Freeze-dried cancellous allogeneic bone blocks showed equivalent volumetric shrinkage rates as autogenous bone blocks when used for treating circumscribed bone defects classified as Type-II to Type-IV according to the ITI-treatment guide categories. Therefore, it is not necessary to over-contour the alveolar ridge when using allogeneic blocks for treating single tooth defects, but to apply the same procedure as when using autogenous blocks.
Project description:Secondary corrective osteotomy of malunited craniofacial fractures can be a challenging proposition. The exposure, extrusion, and palpability of the titanium implants used become a genuine concern especially in areas of relatively thin skin, such as the periorbital region. Restoring a satisfactory contour to the midface is another major task for the plastic surgeon. Bone cement used to reconstruct craniofacial defects has existed for many years. However, most applications have been as a substitute for autogenous bone grafts for defects less than 25 cm(2). In this article, we present two cases of malunited facial fractures that underwent corrective osteotomy, during which we felt that despite the conventional osteotomy and reduction techniques, there was still either a small remnant step deformity or suboptimal contour smoothness due to prominence of the implants used. We thus used bone cement as a resurfacing medium over titanium implants to restore good malar contour and reduce the palpability and exposure rate of the titanium implants. We report good patient satisfaction with contour correction with no increase in wound infection rates or any delay in wound healing. There was initial chemosis associated with the use of the bone cement, which resolved in both patients within 3 to 4 weeks. Postoperative computed tomography showed some degree of osteointegration but no fraction of the bone cement. Calcium phosphate bone cement thus presents an attractive adjunctive method for midfacial contour resurfacing, when used in conjunction with conventional osteotomy procedures and as an onlay over prominent titanium implants.
Project description:Reconstruction of mandibular defects following tumor resection in infants is a particular challenge. Although autogenous rib grafts have no relevance in the restoration of mandibular bone defects occurring after ablative tumor surgery due to limited bone stock and the availability of other donor areas, they are a useful surgical alternative following tumor surgery in infants. We here report on a 2, 5, 8, and 15-year follow-up of four children who were diagnosed with benign tumors of the mandible with osseous destruction at the age of 4, 6, 15, and 18 months, respectively. Histologic diagnoses were melanotic neuroectodermal tumor (n = 2), hemangioendothelioma of the mandible (n = 1), and ameloblastoma (n = 1). Following continuity resection of the mandible, lateromandibular bone defects were restored using autogenous rib grafts. Both clinical and radiologic follow-up visits were performed for all children to assess growth of the facial skeleton and the mandible. One child was already further reconstructed using bone augmentation at the age of 15 years. Cephalometric measurements on panorex films and three-dimensional computed tomographic scans revealed a slight vertical growth excess and transversal growth inhibition of the reconstructed mandible compared with the nonoperated side. Although further growth of rib grafts is difficult to predict and occlusal disharmony may occur due to physiologic maxillary growth and growth of the unaffected mandible, we believe that autogenous rib grafts can be ideally used for the restoration of mandibular continuity defects in newborns and young children. Clinical follow-up visits on a yearly basis and orthodontic controls are useful for early orthodontic treatment of growth deficits. Further corrective surgery with bone augmentation or osseous distraction is required following completion of growth of the facial skeleton.
Project description:Cracking is a major concern in building applications. Cracks may arise from shrinkage, freeze/thawing and/or structural stresses, amongst others. Several solutions can be found but superabsorbent polymers (SAPs) seem to be interesting to counteract these problems. At an early age, the absorbed water by the SAPs may be used to mitigate autogenous and plastic shrinkage. The formed macro pores may increase the freeze/thaw resistance. The swelling upon water ingress may seal a crack from intruding fluids and may regain the overall water-tightness. The latter water may promote autogenous healing. The use of superabsorbent polymers is thus very interesting. This review paper summarizes the current research and gives a critical note towards the use of superabsorbent polymers in cementitious materials.
Project description:BACKGROUND:The use of guided bone regeneration (GBR) for vertical and horizontal bone gain is a predictable approach to correct the bone defects before implant installation; however, the use of different protocols is associated with different clinical results. It is suggested that platelet-rich fibrin (PRF) could improve the outcomes of regenerative procedures. Thus, this study aimed to describe the bone gain associated with GBR procedures combining membranes, bone grafts, and PRF for vertical and horizontal bone augmentation. MATERIALS AND METHODS:Eighteen patients who needed vertical or horizontal bone regeneration before installing dental implants were included in the study. The horizontal bone defects were treated with a GBR protocol that includes the use of a mixture of particulate autogenous and xenogenous grafts in the proportion of 1:1, injectable form of PRF (i-PRF) to agglutinate the graft, an absorbable collagen membrane covering the regenerated region, and leukocyte PRF (L-PRF) membrane covering the GBR membrane. The vertical bone defects were treated with the same grafted mixture protected by a titanium-reinforced non-resorbable high-density polytetrafluoroethylene (d-PTFE-Ti) membrane and covered by L-PRF. The bone gain was measured using a cone-beam computed tomography at baseline and after a period of 7.5 (± 1.0) months. RESULTS:All patients underwent surgery to install implants after this regenerative protocol. The GBR produces an increase in bone thickness (p < 0.001) and height (p < 0.005) after treatment, with a bone gain of 5.9 ± 2.4 for horizontal defects and 5.6 ± 2.6 for vertical defects. In horizontal defects, the gain was higher in the maxilla than in mandible (p = 0.014) and in anterior than the posterior region (p = 0.033). No differences related to GBR location were observed in vertical defects (p > 0.05). CONCLUSION:GBR associated with a mixture of particulate autogenous and xenogenous grafts and i-PRF is effective for vertical and horizontal bone augmentation in maxillary and mandibular regions, permitting sufficient bone gain to future implant placement. TRIAL REGISTRATION:REBEC, RBR-3CSG3J . Date of registration-19 July 2019, retrospectively registered. http://www.ensaiosclinicos.gov.br/rg/RBR-3csg3j/.
Project description:The appropriate surgical technique for the treatment of unstable osteochondral lesions of the knee remains unclear and had been traditionally described with an open arthrotomy. Administration of bone grafting material in the knee may be performed for a variety of pathologic conditions, including unstable osteochondritis dissecans, traumatic osteochondral defects, or subchondral fracture nonunion, or for preparation of residual tunnels during revision anterior cruciate ligament reconstruction. Although various grafting materials have been described in the literature, cancellous autograft remains the gold standard for treatment safety and efficacy. We describe a successful technique for arthroscopic delivery of autogenous bone graft during fixation of unstable osteochondral lesions of the knee. When the indication for grafting is established, cancellous autograft is harvested from the proximal tibia, undergoes morcellation, and is soaked in bone marrow aspirate obtained through the harvest window. The bone graft is then packed into a modified tuberculin syringe. After arthroscopic preparation of the unstable osteochondral fragment and the respective donor surface, the tuberculin syringe is placed through a standard arthroscopy portal and the bone graft is introduced into the defect under direct visualization, followed by an appropriate osteochondral fixation technique.
Project description:The purpose of the current investigation was to evaluate the clinical success of horizontal ridge augmentation in severely atrophic maxilla (Cawood and Howell class IV) using freeze-dried custom made bone harvested from the tibial hemiplateau of cadaver donors, and to analyze the marginal bone level gain prior to dental implant placement at nine months subsequent to bone grafting and before prosthetic rehabilitation. A 52-year-old woman received custom made bone grafts. The patient underwent CT scans two weeks prior and nine months after surgery for graft volume and density analysis. The clinical and radiographic bone observations showed a very low rate of resorption after bone graft and implant placement. The custom-made allograft material was a highly effective modality for restoring the alveolar horizontal ridge, resulting in a reduction of the need to obtain autogenous bone from a secondary site with predictable procedure. Further studies are needed to investigate its behavior at longer time periods.
Project description:The use of impacted morselized cancellous bone grafts in conjunction with cementless hemispherical acetabular cups for treatment of AAOS type II acetabular cavitary deficiencies was evaluated in a retrospective study of 23 primary and 24 revision total hip arthroplasties, at a mean follow-up of 7.9 and 8.1 years, respectively. All primary hips received autografts, while all revision hips received allografts. Modified Harris Hip Scores for primary and revision hip replacements increased from a pre-operative mean of 37 and 47 to a postoperative mean of 90 and 86, respectively. All 23 autografts and 23 out of 24 cancellous allografts were radiographically incorporated without evidence of resorption. There were no instances of infection, component migration, or cases requiring subsequent acetabular revision. We conclude that impacted morselized cancellous bone-graft augmentation of cementless cups is a viable surgical option for AAOS type II cavitary acetabular defects.
Project description:UNLABELLED: During revision total shoulder arthroplasty, bone grafting severe glenoid defects without concomitant reinsertion of a glenoid prosthesis may be the only viable reconstructive option. However, the fate of these grafts is unknown. We questioned the durability and subsidence of the graft and the associated clinical outcomes in patients who have this procedure. We retrospectively reviewed 11 patients with severe glenoid deficiencies from aseptic loosening of a glenoid component who underwent conversion of a total shoulder arthroplasty to a humeral head replacement and glenoid bone grafting. Large cavitary defects were grafted with either allograft cancellous chips or bulk structural allograft, depending on the presence or absence of glenoid vault wall defects, without prosthetic glenoid resurfacing. Clinical outcomes (Penn Shoulder Score, maximum 100 points) improved from 23 to 57 at a minimum 2-year followup (mean, 38 months; range, 24-73 months). However, we observed substantial graft subsidence in all patients, with eight of 11 patients having subsidence greater than 5 mm; the magnitude of graft resorption did not correlate with clinical outcome scores. Greater subsidence was seen with structural than cancellous chip allografts. Bone grafting large glenoid defects during revision shoulder arthroplasty can improve clinical outcome scores, but the substantial resorption of the graft material remains a concern. LEVEL OF EVIDENCE: Level III Prognostic study.
Project description:Despite the popularity of anterior cruciate ligament (ACL) reconstruction procedures, the ideal graft for reconstruction remains a matter of controversy. The ideal graft for ACL reconstruction should have histologic and biomechanical characteristics similar to those of the native ACL; should be quickly and fully incorporated within the bony tunnels; should maintain its viscoelastic properties for a long time; should have minimal donor-site morbidity; should be of sufficient length and diameter; should have minimal adverse effects on the extensor mechanism; should have no risk of rejection or disease transmission; and should be cost-effective and readily available. Synthetic grafts are not widely accepted because of their dangerous complications. The main sources of grafts for ACL reconstruction are allografts and autografts. Each type of graft has its own relative advantages and disadvantages. Allografts are not available in every country, besides being expensive, and there are many concerns regarding disease transmission. Autografts, particularly bone-patellar tendon-bone (BPTB), and hamstring tendon grafts have been the standard for ACL reconstruction. The main advantage of autogenous BPTB grafts is the direct bone-to-bone healing in the tunnel, whereas the main disadvantages of such grafts are related to donor-site morbidity, anterior knee pain, and extensor mechanism dysfunction. The popularity of autogenous hamstring tendon grafts for ACL reconstruction is increasing, but there are still concerns regarding the slow soft tissue-to-bone healing, with delayed healing and incorporation of the graft. We describe a technique for ACL reconstruction with autogenous hamstring-bone graft, aiming to produce a type of graft that combines the main advantages of BPTB and hamstring grafts, with avoidance of the main disadvantages of these 2 most commonly used graft types in ACL reconstruction.
Project description:This study evaluated postoperative results of 8 cases of frontal sinus fractures treated by frontal sinus obliteration with autogenous bone from the anterior iliac crest.The medical charts of patients sequentially treated for frontal sinus fractures by obliteration with autogenous cancellous iliac crest bone in the Oral and Maxillofacial Surgery Division of this institution were reviewed. From those, eight had complete records and adequately described long-term follow-up. All were operated by the same surgical team. Those patients were recalled and independently evaluated by 2 examiners. Radiographs and/or CT scans were available for this evaluation. Associated fractures and complications were noted. The average postoperative follow-up was 7 years, ranging from 3 to 16 years. The main complication was infection. Four patients (50%) had uneventful long-term follow-ups and four (50%) experienced complications requiring reoperation. Based on the studied sample studied the authors conclude that the obliteration with autogenous bone presented a high percentage of complications in this series.