Critical Size Defect as an Experimental Model for Craniomaxillofacial Nonunions

摘要

Little consistency has been maintained among research investigators in choosing an appropriate animal model for maxillofacial bone research. In an attempt to describe a protocol for the development of maxillofacial nonunions, experiments were reviewed which used calvarial and mandibular defects as models. The creation of experimental nonunions in the calvaria and mandible was found to be size-dependent. Defects of a size which will not heal during the lifetime of the animal may be termed critical size defects (CSD's). A rationale was postulated for testing bone repair materials (BRM's) using CSD's in a hierarchy of animal models. This protocol suggests that testing would be initiated in the calvaria of the rat and rabbit followed by testing in the mandibles of dogs and monkeys. While calvarial CSD's have been established in the rat, rabbit, and dog, research is still needed to describe the CSD in the calveria of the monkey and the mandibles of dogs and monkeys.