Radiologic evaluation of irradiated cartilage grafts on the facial skeleton of sheep.

Augmentation mentoplasty is a commonly performed procedure for correction of retrognathia and microgenia. Implantable Silastic prostheses have become the mainstay of therapy, but have some disadvantages. One of the most important complications is erosion of the underlying mandible. An attempt was made to produce an experimental animal model to test the efficacy of irradiated costochondral cartilage in this regard. In order to prevent a biological material from eroding the underlying bone, the irradiated sheep cartilage grafts were placed subperiosteally, deep to a pair of large muscles of facial expression in five Suffolk sheep. Irradiated cartilage was used as the test material and merthiolate-treated cartilage as the control. Only 1 of the 20 grafts showed any absorption after 1 year, and this was only 1 mm in depth. Because of the meager amount of absorption of irradiated cartilage grafts, the ease with which they can be carved, and their ready availability, they would appear to be ideal implants for chin augmentation.