Modern imaging of petrous bone malformations: improvement for clinical-embryological correlations.

The rapid perfecting of modern diagnostic imaging during the past decade has provided several new ways to explore ear malformations. Helical computed tomography, three-dimensional (3D) reformations, virtual endoscopy and thin-sliced 3D magnetic resonance imaging constitute the most important recent progress. In parallel, conventional morphologic studies and modern teratologic experimentation give rise to new concepts relative to ear development. The molecular and genetic control of ear morphogenesis is becoming better known, and several malformations can be considered as a consequence of a disruption of genetic or morphogenetic processes. The role of the homeobox genes is particularly important in normal and abnormal development. The field in which radio-embryologic correlations are possible is presently very wide and includes: the association of vestibular defects and lenticulo-stapedial malformations; abnormalities in cochlear coiling; complex ossicular abnormalities; and 'branchial' syndromes. Several experimental models in animals can reproduce this variety of malformations.