OMFS training revisited.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to M Heliotis.
Explore the source record for details and available documents.
We describe the intramuscular transformation of a hydroxyapatite/osteogenic protein-1 (HA/OP-1) composite implant, into a vascularised pedicled bone flap useful for reconstruction of a hemi-mandible. Extraskeletal induction of a bone flap for transplantation was achieved without the addition of harvested bone, bone marrow, or stem cells. Five months after apparent clinical success, an MRSA infection of the graft led to its failure. The background to ectopically induced bone flaps is introduced, with our experience in a human case presented. The results from this emerging biotechnology are discussed in the light of limited human clinical experience.
Reconstruction of the mandible with a vascularised bone graft from the iliac crest based on the deep circumflex iliac artery is an established and reliable technique. We report two cases in which mandibular asymmetry followed reconstruction with such grafts and was corrected by sagittal split osteotomies.
Major advances in the understanding of bone regeneration have led to revolutionary applications of bone conduction and induction. Revision hip surgery is on the increase with an active, ageing population demanding increased quality of life. The technically demanding instrumentation and materials necessary for revision prosthetic hip replacements have been rapidly incorporated into clinical practice. Unfortunately, advantage has not been taken of the basic and fundamental principles of bone induction and regeneration, available for many years now. In impaction grafting for revision hip replacements where fresh frozen bone is currently used as a standard, we argue and demonstrate from the literature why this technique is biologically inferior to the results which potentially can be gained by exploiting osteoinductive grafts such as demineralised bone matrix, hydroxyapetite, and inductive factors such as bone morphogenetic proteins.
Explore the source record for details and available documents.
Recombinant human osteogenic protein-1 (hOP-1), a member of the bone morphogenetic protein family, was examined for its efficacy in periodontal regeneration. Twelve furcation defects, surgically prepared in the first and second mandibular molars, were treated with bovine insoluble collagenous matrix in conjunction with 0.0 (control), 100 and 500 mu g of recombinant hOP-1 per g of matrix. After 60 days of healing, histological and histometric analyses on serial, undemineralized sections cut at 7 mu m showed substantial cementogenesis on the exposed dentine of furcations treated with both doses of hOP-1 (p < 0.01 vs control). Foci of nascent mineralization were seen within the newly deposited cementoid along the coronal areas of hOP-1-treated defects. Within the furcations, there were substantial amounts of residual collagenous carrier, interspersed with a mineralized matrix having histological features of cementum. This mineralized cementum-like material was predominantly deposited around the carrier, and blended into newly formed cementum along the root surfaces. In the apical area, the cementum-like material and the remaining alveolar bony housing were not connected; indeed the two components were separated by a fibrovascular tissue that had numerous features of the periodontal ligament space. Formation and insertion of Sharpey's fibres into newly formed root cementum were also observed. It is likely that the expression of specific cell phenotypes by hOP-1 is regulated, in part, by the extracellular matrix microenvironment, including dentine. Thus, exposed dentine, in the presence of exogenous hOP-1 at the doses tested, may preferentially modulate the expression of the cementogenic phenotype. These findings in a non-human primate show that hOP-1, at the doses tested, induced cementogenesis on surgically denuded root surfaces, indicating a specific function during repair and regeneration of periodontal tissues.
Explore the source record for details and available documents.
Explore the source record for details and available documents.