This document discusses maxillofacial prosthetics, which are artificial devices used to replace missing facial or oral structures. It describes various types of maxillofacial defects including cleft lip and palate, acquired defects from surgery or trauma, and extraoral defects. The goals of maxillofacial prosthetics are to preserve remaining structures, reconstruct function, and improve aesthetics. Common materials used include silicone, acrylic, and metals.