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.