| The minimization of morbidity in cranio-maxillofacial osseous reconstruction: Bone graft harvesting and coral-derived granules as a bone graft substitute | ||
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Autogenous bone grafts are usually classified as either vascularized or nonvascularized (Marx 1993). The difference is that vascularized grafts retain their existing network of nutrient vessels which, when anastamosed with the recipient blood vessels at the site of reconstruction will make the graft immediately viable by providing an instant and intact blood supply (Shpitzer et al. 1997b). Therefore these types of bone grafts are particularly well suited in poorly vascularized recipient beds, such as those exposed to radiation therapy (Schmelziesen & Schon 1998, Shpitzer et al. 1999).
Possible donor sites for osseous cranio-maxillofacial reconstruction include radial forearm, scapula, anterior iliac crest, fibula and metatarsal. A major drawback to this form of transplant is that the surgical harvesting and reanastamosing of this type of graft is very time consuming, extremely invasive and creates significant morbidity, with unsightly donor site defects, which in some cases may cause longstanding functional impairment (Tang et al. 1998, Shpitzer et al. 1997a).
Both intra-oral and extra-oral bony donor sites have been used successfully as sources of non-vascularized autogenous bone for grafting of maxillofacial defects (Marx 1993). The volume of bone graft required determines the choice of the donor site.
If the defect is small, often local, intra-oral sources can be used (Sindet-Pederson & Enemark 1990). Intra-oral sites are often preferred since they allow harvesting of bone from the area adjacent to the reconstruction. A second distant surgical site and the extra-oral scar can be avoided. Intra-oral harvesting can mostly be performed on an outpatient basis under local anaesthesia. These intra-oral sites can include mandibular symphysis, mandibular ramus and retromolar area, coronoid process, maxillary tuberosity, maxillary torus palatinus or mandibular tori, if they are present, and the zygomatic bone. These sites can be harvested using a specially designed bone collector or suction trap (Oikarinen et al. 1997, Kainulainen et al. 2002c). However the volume of bone available in intra-oral sites may be insufficient for moderate to large defects (Kainulainen et al. 2002a).
When a greater volume of bone is required, extra-oral sources are usually employed. These may include the anterior or posterior iliac crest, the calvarium, the rib and the proximal tibia (O’Keefe et al. 1991, Boyne 1997, Kainulainen et al. 2002b).