Atrophic mandible reconstruction using calvarial bone grafts and implant-supported overdentures: Radiographic assessment of autograft healing and adaptation
Bone grafting constitutes a vital surgical procedure in the management of severely atrophic mandibles. In this regard, calvarial bone autografts are applied in the reconstruction of wide mandibular defects caused by edentulousness and long-term denture-related resorption. Grafts are used as a framework to augment the residual ridge and provide implant stability for further prosthetic restoration. On the basis that radiographic evidence corresponds to biologic changes in bone response to transplantation and loading, the goal of this article is to document the radiographic assessment of calvarial autologous bone grafts in the recipient site. Panoramic radiographs were used to evaluate bone changes occurring during both the graft healing period and graft adaptation after implant loading. Emerging data show that conventional panoramic radiography may have an effect on the investigation of bone grafts and provide initial information about graft incorporation and adaptation.
Available from: Cristina Barona
- "In general, the success of a bone graft is measured in terms of its capacity to withstand the conditions of tension and mechanical deformation to which it is subjected (8). "
[Show abstract] [Hide abstract]
ABSTRACT: To evaluate graft types used for maxillary sinus augmentation and review success rates of dental implants inserted in these areas, analyzing the graft materials used, implant surface types and the moment of implant placement.
A meta-analytic study reviewing articles on sinus augmentation published during the last ten years.
3,975 implants placed in sinus augmentations (with bony windows) were registered, of which 3,749 implants survived, a survival rate of 94.3%.
When performing sinus augmentation, bone substitute materials are just as effective as autologous bone, whether used alone or in combination with autologous bone. Implant surface treatments can have an important effect on implant survival and it would appear that roughened surfaces are the best option. When implants are inserted simultaneously to grafting, a higher failure rate can be expected.
Available from: Vincenzo Luca Zizzari
- "repairs than endochondral grafts in craniofacial defects (Wong & Rabie 1999; Bianchi et al. 2004; Crespi et al. 2007). Moreover, many authors agree that, independently of the embryologic origin, the number of the corticals and the macroscopic architecture of the tissue harvested might affect the clinical success in bone grafting (Lu & Rabie 2004). "
[Show abstract] [Hide abstract]
ABSTRACT: The aim of this study was to investigate, in parallel to clinical and histological modifications, the expression of specific proteins involved in different extraoral autologous bone grafts integration in humans.
Patients needing oral rehabilitation of posterior maxilla, with inadequate bone volume for implant placement, received bone grafts from calvaria (Group 1) and iliac crest (Group 2), respectively. From five patients from each group, with a total of 10 subjects, bone biopsy specimens were collected at two different experimental time points: at bone blocks withdrawal for grafting (T0), from donor sites, and after 4 months, from reconstructed sites. Samples were processed for light microscope and immunohistochemical analyses to evaluate MMP9, VEGF, BSP, iNOS expression.
Morphological analysis of T0 calvaria evidenced areas of extracellular matrix, uniformly stained and organized in concentric mineralized lamellae edging few vascular canals, while T0 iliac crest showed greater cellularity compared to calvaria, with rare mineralized areas, surrounding wide bone marrow lacunae. In T1, Group 1 samples showed large areas of extracellular matrix, uniformly stained, at the same time as Group 2 samples disclosed few areas of mineralized tissue. Although no significant differences were found in proteins expression among calvaria and iliac crest T0 samples, MMP9, VEGF and BSP expression at T1 were discovered higher in Group 1 samples than in Group 2 ones, while iNOS expression increased in Group 2 samples compared to the others. In any group, molecules expression increased passing from T0 to T1.
These findings suggested that, even though clinically both extraoral sources of autologous bone could be considered suitable for grafting in case of large oral rehabilitation, some differences might be detected microscopically and biologically. Calvaria bone graft seemed to enhance not only the quantity of bone tissue at the defect site, but also its quality, better than iliac crest bone do. Then, while both grafts appeared to promote a suitable neoangiogenesis, as showed by morphological analysis and by MMP9 and VEGF expression, in terms of new bone formation and lack of occurrence of inflammatory events, calvaria could be considered a more suitable donor site for bone grafts.
[Show abstract] [Hide abstract]
ABSTRACT: This article describes reconstruction of the severely atrophic mandible using calvarial bone grafts for implant-supported prosthetic oral rehabilitation. The study aim was to evaluate the efficacy of the treatment by determining implant survival and complication rates, and the extent of the postoperative graft resorption.
Ten patients who underwent the treatment were followed clinically and radiologically using panoramic radiographs and CT scans during a mean postoperative period of 30 months.
Good bone healing was observable 6 months postoperatively. The height reduction measured on panoramic radiographs was insignificant (mean 0.68 mm). Only minor complications occurred. Implant survival was 95%. Prosthodontic treatment was successfully performed in all cases, resulting in an improvement of oral function. Histological analysis of 1 bone biopsy showed minimal resorptive changes in otherwise very dense bone.
Augmentation using calvarial grafts is a promising treatment alternative for the severely atrophic mandible.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.