Analysis of Morphologic Differences between Pneumatic and Sclerotic Mastoids in the Unilateral Sclerotic Temporal Bone

Lee, Dong Hee; Jun, Beom Cho; Lee, Jung Hak; Lee, Dong Ho; Yeo, Sang Won

Abstract

BACKGROUND AND OBJECTIVES
Some pathologies, such as otitis media or E-tube dysfunction, may cause sclerosis in the temporal bone, which then tends to shrink in size. The aim of this study is to evaluate morphologic changes that result from sclerosis in the temporal bone. SUBJECTS AND METHOD: We measured 9 variables on 2 axial images and 7 variables on 2 coronal images in healthy ears and diseased ears of 37 unilateral chronic otitis media patients. We also measured the volume of the mastoid pneumatization. RESULTS: The mastoid volume in the sclerotic temporal bones was significantly smaller than that in the pneumatic ones. The distance from sigmoid sinus to Henle's spine was most significantly correlated to the degree of volume reduction, and it accounted for about 17.7% of the total variation in volume reduction. There was no difference in sigmoid sinus types between sclerotic and pneumatic mastoids. CONCLUSION: The sclerosis of the temporal bone reduces the volume of mastoid pneumatization. However, the large portion of volume reduction may result from the sclerotic change in the air cell system, rather than from the shrinkage of the mastoid bone. So, the location of surgically-important structures in the middle and inner ears is rarely changed in the sclerotic temporal bone.