Appropriate animal models for craniofacial biology.

The use of animal models in craniofacial biology has helped make significant contributions toward the clinical and surgical management of patients with craniofacial disorders. The present paper discusses some problems associated with choosing appropriate animal models for research in human craniofacial morphology and offers suggestions for determining the most appropriate model. Three levels of appropriate animal model choices are suggested: (1) the "generic mammalian" animal model, useful for investigating the problems of bone biology and generalized mammalian craniofacial growth mechanisms; (2) the "phylogenetically closer" animal model, useful for investigating the influence of experimental manipulations on the general primate craniofacial growth pattern; and (3) "fitting" the appropriate animal model to specific regional craniofacial growth patterns or anatomic conditions of interest. The continued, intelligent use of animal models in craniofacial investigations depends heavily on understanding and appreciating the information that can be derived from the "appropriate" animal model.