Bone grafting graft requirements

Bone is one of the few tissues capable of self-regeneration during skeletal deficiency, but this regeneration is limited by the nature and size of the defect. In general, skeletal deficiency occurs as a result of trauma, tumor, bone disease, or abnormality. In the case of severe fracture, bone will not heal by itself. For this reason, artificial bone substitutes may be required to restore routine function without damaging living tissue, and the selection of the bone graft substitute is the most important factor for better performance in vivo. 

Ideally, bone substitute materials should be replaced by mature bone without transient loss of mechanical support. Unfortunately, at present there is no material available fulfilling these requirements. Consequently, mechanically unstable bone defects ought to be stabilised with a non-resorbable metallic fixation made from stainless steel or titanium and the bone defect filled with a bone graft substitute. While the mechanical properties of the bone graft substitute are of minor importance, much more important it is to optimise the resorption rate of the bone graft substitute to minimise the time required for bone healing (Bohner, 2010). To control the resorption rate several strategies such as modification of the... 

There are two t5 es of bone tissue in the human oiganism. Cortical bone thanks to the presence of Haversian channels shows good osteoconductive properties. Thanks to its mechanical properties it can be used in cases when recreation of tridimensional cavities within the facial part of the skeleton is required. As opposed to cortical bone, cancellous bone is extremely rich in osteogenic cells. Living osteoblasts of cancellous bone may survive even for a few hours from the time of harvesting of the tissue early revascularization in closed cavities takes place after 48 hr. The disadvantage of the cancellous bone grafts is their small mechanical endurance. It is also connected with the lack of possibility to use them in case of tridimensional reconstructions [3]. 

In such cases, a two-stage procedure is not required. Even if bone grafting is needed for bone defects due to the previous tunnel or implant removal, bone grafting and a revision procedure can be simultaneously performed. 

Fractures of the mandible head or neck carry a particular risk of cosmetic deformity and abnormal bite if not corrected into acceptable anatomical position. 3D CT is used, as in other examples of facial trauma, to display the spatial distribution of the fragments and their relation to the joint (Salvolini 2002). Mai-alignment of the mandibular condyle is particularly important to demonstrate or exclude, as are those fractures classed as unfavourable for stabilisation because of opposing muscle pull these fractures require operative fixation. Post operative imaging maybe helpful to confirm satisfactory positioning, or placement of bone grafts, and healing (Ray et al. 1993). 

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