Fibrotic tissue or new bone occurs following inner ear inflammation, fracture, or surgery. The prevalence is unknown and was investigated using the National Temporal Bone, Hearing and Balance Pathology Resource Registry database. A search yielded 264 temporal bones with diagnoses of otosclerosis, tumor, Meniere's disease, meningitis, labyrinthitis, chronic otitis media, autoimmune disease, temporal bone fracture, or sensorineural hearing loss. All autoimmune cases contained some new bone, whereas only 20% to 30% of the labyrinthitis/meningitis cases were reported to contain new bone. Otosclerosis, Meniere's disease, and otitis media had relatively few cases containing new bone. Although new bone may derive from surgical trauma, it is also likely to be a result of the disease process. It seems that all these disease processes may contain a common feature that acts as a stimulus to induce fibrosis or bone growth in the inner ear.