The effect of chronic middle ear inflammation on the pneumatization of the tympanic bulla in pigs.

The effect of chronic middle ear inflammation on the pneumatization of the tympanic bulla was investigated in piglets. The pig tympanic bulla has an air cell system which is divided by trabeculae and closely resembles the human mastoid air cell system. The tympanic bulla and its air cell system in normal ears were well developed because of the bone formation and the bone resorption inside the cortex, whereas the tympanic bulla affected by chronic otitis media in the early stages of life exhibited retardation of pneumatization arising from the disturbed bone resorption by inflammatory stimulus. It was concluded that affliction with chronic middle ear inflammation in the early stages of life causes inhibition of pneumatization by hindering the development of the air cell system.