Tomography of petrous bone in deafness associated with Paget's disease.

Two cases of Paget's disease presenting with deafness are described. Tomography of the petrous bones showed, in both cases, an upward tilt of the long axes of the bones including their auditory canals, generalized sclerosis of the petrous pyramids and enlargement of the ossicles. In one case, there was narrowing of the internal auditory canal. Review of the literature revealed three radiological phases in Paget's disease of the temporal bone:--(i) early changes consisting mainly of demineralisation; (ii) an intermediate phase consisting of diminishing visibility of the semicircular canals and cochlea; and (iii) a late phase consisting of complete blotting out of the structures of the optic capsule and replacement of the ossicles by Pagetic bone. Our two cases fall within the last phase.