Biologic effects of freezing on tissues of the maxillofacial region.

An experimental study was done on the effects of freezing on various tissues of the maxillofacial region. After freezing, skin became necrotic, but the wound healed with a flat surface. Blood vessels showed injury of the endothelial cells and thrombosis in the veins. The internal wall of some arteries became thickened, and the lumen was narrowed. Paralysis of the facial nerve occurred immediately after freezing. Function usually recovered several weeks later. Cartilage and bone showed no change in shape after freezing, but the cells were destroyed. New cartilage and bone formation were seen in the later stages.