The Classification and Clinical Importance of the Anterior Attic Bony Plate on Temporal Bone CT

Lee, Chul Hee; Lee, Ji Eun; Sang, Dong Min; Kim, Hyeun Woo; Lee, Jung Rea; Cho, Tae Hwan; Lee, Sang Hun

Abstract

BACKGROUND AND OBJECTIVES: Anterior attic bony plate (cog) is a coronally oriented bony septum which is suspended from the anterior petrosal tegmen, and the anterior epitympanic recess is partitioned from epitympanum by this bony plate. It is an important pathway for anterior drainage which can cause inflammation in obstructed conditions; therefore, it needs appropriate procedure to eradicate the lesions without recurrence. We aimed to classify types of the anterior attic bony plates on the temporal bone CT and to find correlation between the types of the anterior attic bony plates and the development of chronic otitis media and cholesteatoma.
MATERIALS AND METHODS
We reviewed 264 cases of the temporal bone CT of the normal and the chronic otitis media patients, of which 64 cases were excluded as lesions could not be identified due to severe destruction and obscurity of the figure.
RESULTS
In normal ears, the incidence of the anterior attic bony plate was 67% in the plate type, 28% in the pyramid type, and 5% in the anterior type. In the diseased ear, the incidences were 40%, 44%, 16%, in the plate type, pyramid type, and anterior type, respectively and in the cholesteatoma ear, 30%, 43%, 27%, respectively. The difference of incidence was statistically significant.
CONCLUSION
We assumed that the development of the chronic otitis media is related to the type of the anterior attic bony plate in some degree. Especially, the anterior type was more prominent in cholesteatoma than in noncholesteatoma with a statistical significance. Further studies are needed to figure out the correlation between the type of the anterior attic bony plate and it's clinical importance.