4.1.2 Labyrinthitis ossificans
Labyrinthitis ossificans indicates the fibrosis or ossification of the membranous labyrinth. Tympanogenic, meningogenic, and hematogenous etiologies are more common in cases of labyrinthitis ossificans than in those related to trauma.6 A report found the incidence of tympanogenic labyrinthitis ossificans to be 2%.7The most common risk factors for labyrinthitis ossificans are chronic otitis media and temporal bone surgery. Regardless of etiology, labyrinthitis ossificans affects the semicircular canals with the greatest severity and the vestibules with the least severity.8 This study identified the bony semicircular canal as the ossification center of EC-LSC in all patients with growth mainly occurring in the direction of the tympanic antrum and attic. This may be different from the pathogenesis of labyrinthitis ossificans.