Variations of Surgical Anatomy in the Unilateral Sclerotic Temporal Bone

Lee, Seung Hwan; Seo, In Seok; Kim, Ki Tae; Jang, Young Ho; Kim, Kyung Rae; Park, Chul Won

Abstract

BACKGROUND AND OBJECTIVES
Temporal bone has a difficult anatomical structure for otologists. High resolution computed tomography (HRCT) helps locating the anatomical structure within the temporal bone. The aim of this study is to examine the anatomical relationship between the various surgical structures and pneumatization of unilateral sclerotic temporal bone using HRCT. SUBJECTS AND METHOD: We measured 11 distances and sigmoid sinus type on axial image, 6 distances on coronal image between important surgical landmarks of unilateral sclerotic temporal bone HRCT in 124 ears. The data of sclerotic side were compared with pneumatic side. RESULTS: The shortest distances from sigmoid sinus to lateral wall of mastoid cortex, middle cranial fossa, and posterior wall of external auditory canal, the shortest distance from tegmen to superior margin of lateral semicircular canal and superior wall of external auditory canal were significantly influenced by pneumatization. Half-moon and protrusion type of sigmoid sinus were dominant in sclerotic side. CONCLUSION: The location of sigmoid sinus and middle cranial fossa was affected significantly by temporal bone pneumatization.