Computed Tomographic Measurements of the External Auditory Canal and the Temporal Bone

Koo, Gyo Jun; Goh, Eui Kyung; Yun, Jun Ho; Lee, Chang Hun; Koo, Soo Kweon; Lee, Sang Hwa; Chon, Kyung Myung

Abstract

BACKGROUND AND OBJECTIVES: High-resolution computed tomography provides an excellent method for examination of the middle ear, inner ear anatomy and pathologic changes in the temporal bones. The purpose of this study was to get various measurements of the external auditory canal and temporal bones, and to compare the changes with age and sex. MATERIALS AND METHOD: The various measurements by CT of the external ear canal of normal 50 ears were done.
RESULTS
The obtained results were as follows: 1) In both male and female group, the distance from the medial end of EAC to bony-cartilage junction, the distance from medial end of EAC to the lateral end of cartilage, the distance from the superior wall to the inferior wall (coronal EAC isthmus) and the distance from anterior wall to the posterior wall (axial EAC isthmus) increased significantly with age (p<0.05). 2) Compared with the female group, the male group had longer distance from the posterior tympanic plate to the sinus tympani with age (p<0.05). 3) Compared with male group, the female group had longer distance from the posterior EAC wall to the Sigmoid sinus and from the EAC superior wall to the tegmen tympani with age (p<0.05). 4) In both male and female groups, the anterior and inferior angles increased and the posterior and superior angles decreased with age (p<0.05).
CONCLUSION
Computed tomographic evaluation can give us to information to operate external ear, middle ear, and inner ear surgery.