2.2. Bony defects in the cranio-maxillofacial skeleton

Bony defects in the cranio-maxillofacial skeleton can cause severe functional and aesthetic deformities. They can arise from congenital malformations, traumatic avulsions or be the result of ablative tumour surgical resections. Surgeons have tried a variety of materials and methods to restore such defects. In Mayan times nacre or mother of pearl was used to try to reconstruct bony defects and as implants into the tooth bearing areas of the jaws (Lopez et al. 1995). The first recorded use of an alloplast to restore a skull defect was by Fallopius in 1600, who used a gold plate to reconstruct a calvarial defect (Moghadam 2002). Autogenous bone grafting was reported in 1890 to restore a skull defect by harvesting bone from the cranium (Muller 1890). Since that time autogenous grafts have continued to be used, although there has been a search for substitute materials. In order to decrease the morbidity of bony reconstruction both less invasive harvesting methods, which aim to reduce post-operative donor site morbidity, or agents that would substitute as bone grafts and would replace the donor site all together, have been sought.