ABSTRACT
Bone reconstruction is required when there are defects in bone, or when bone is absent with missing adjacent soft tissue components. There are numerous causes of bone defects. Congenital bony defects in the craniofacial and maxillofacial skeleton can arise as a result of failed development such as in patients with a cleft lip and palate (Carmichael and Sándor 2008; Figure 16.1). Ablative surgery, in which
16.1 Introduction .................................................................................................. 371 16.2 Bone as a Regenerative Tissue ...................................................................... 372
16.2.1 Intramembranous versus Endochondral Bones .............................. 372 16.2.2 Bone Reconstruction Principles ..................................................... 373 16.2.3 Bone Healing .................................................................................. 374 16.2.4 Cell Signaling Molecules ................................................................ 375 16.2.5 Blood Supply and the Soft Tissue Envelope ................................... 377 16.2.6 VEGF Effects ................................................................................. 377 16.2.7 Angiogenesis ................................................................................... 378
16.3 Surgical Procedures to Induce and Promote Healing of Large Bone Defects ... 381 16.3.1 Periosteal Bone Regeneration ......................................................... 382 16.3.2 Gradual Periosteal Stretching with Distraction Osteogenesis ........ 382 16.3.3 Ancillary Therapy with HBO ......................................................... 383 16.3.4 Tissue Engineering with Growth Factors (BMPs) ..........................384 16.3.5 Tissue Engineering with Stem Cells and Growth Factors .............. 386 16.3.6 Sources of Stem Cells ..................................................................... 387 16.3.7 Physical Stimulation of Stem Cells................................................. 387 16.3.8 Biomaterials .................................................................................... 387 16.3.9 Manipulating the Construct ............................................................ 388 16.3.10 Current Therapy.............................................................................. 388 16.3.11 Future Directions ............................................................................ 389
16.4 Conclusion ....................................................................................................390 References ..............................................................................................................390
segments of bones are removed or resected to treat certain cysts, tumors, or infections, may produce large bony defects (Sándor et al. 2008; Figure 16.2). Large bony defects may result from accidental injury when tissue may have been traumatically avulsed (Sándor and Carmichael 2008). Such combined mucosal, osseous, and even cartilaginous defects can be reconstructed using °aps and bone grafts, or hopefully, in the future, with alloplastic biomaterials such as bone graft substitutes discussed previously in this book or even using cell therapy with tissue-engineered constructs (Sándor and Suuronen 2008). The healing of such complicated wounds always relies on the vascularity of the surrounding tissues (Fok et al. 2008).
