Experimental studies addressing rigid fixation in craniofacial surgery.

This article has reviewed several experimental studies that address certain aspects of the use of rigid fixation in clinical craniofacial surgery. The effect of rigid fixation on growth was studied in an infant Rhesus monkey model. It showed that osteotomy and fixation resulted in subtle changes in skull shape and that the severity of the deformity was related to the complexity of the fixation employed. Deformities were seen with wire fixation alone, however. A study using a rabbit model showed that the revascularization and resorption of onlay bone grafts immobilized with a microscrew occurred primarily in the cancellous portion of the graft. This led Chen et al to speculate that the volume of cranial bone grafts persists better than with iliac crest grafts, because they contain relatively less cancellous bone and more cortical bone, which is slower to revascularize and resorb. Fiala et al studied the artifacts seen in CT and MR scans associated with plate and screw fixation devices. They showed that, compared with stainless steel and vitallium, titanium resulted in less "starburst" and "black hole" artifact in CT and MR images, respectively. Amarante et al compared butyl-2-cyanoacrylate adhesive fixation with fixation by plates and screws of osteotomized bone segments in a minipig model. They found it to be as effective as plates and screws for bone fixation in this model. In the future, this material, together with resorbable plates and screws, may provide a means of fixation of the craniofacial skeleton and can be anticipated to receive further experimental and clinical study.