Anatomical Factors Influencing Pneumatization of the Petrous Apex.
- Author:
Dong Hee LEE
1
;
Min Ju KIM
;
Seunghun LEE
;
Hana CHOI
Author Information
- Publication Type:Original Article
- Keywords: Petrous Bone; Temporal Bone; Growth and Development
- MeSH: Classification; Cranial Fossa, Middle; Cranial Fossa, Posterior; Growth and Development; Humans; Petrous Bone; Retrospective Studies; Saccule and Utricle; Semicircular Canals; Temporal Bone
- From:Clinical and Experimental Otorhinolaryngology 2015;8(4):339-344
- CountryRepublic of Korea
- Language:English
- Abstract: OBJECTIVES: Aim of the present study was to define the relationship between petrous apex pneumatization and the nearby major anatomical landmarks using temporal bone computed tomography (CT) images. METHODS: This retrospective, Institutional Review Board-approved study analyzed CT images of 84 patients that showed normal findings bilaterally. Pneumatization of the petrous apex was classified using two methods. Eight parameters were as follows: angle between the posterior cranial fossa and internal auditory canal, Morimitsu classification of anterior epitympanic space, distance between the carotid canal and jugular bulb, distance between the cochlear modiolus and carotid canal, distance between the tympanic segment and jugular bulb, high jugular bulb, distance between the vertical segment and jugular bulb, and distance between the lateral semicircular canals and middle cranial fossa. RESULTS: There was a significant difference in Morimitsu classification of the anterior epitympanic space between the two classification methods. Poorly pneumatic upper petrous apices were distributed uniformly in three types of Morimitsu classification, but more pneumatic upper petrous apices were found more often in anterior type. Lower petrous apex was well pneumatized regardless of the types of anterior epitympanic space, but the largest amount of pneumatization was found more frequently in the anterior type of anterior epitympanic space. CONCLUSION: This study showed that there was no reliable anatomic marker to estimate petrous apex pneumatization and suggests that the pneumatization of the petrous apex may be an independent process from other part of the temporal bone, and may not be influenced by the nearby major anatomical structures in the temporal bone. In this study, the anterior type of anterior epitympanic space was found to be closely related to more well-pneumatized petrous apices, which implies that the anterior saccule of the saccus medius may be the main factor influencing pneumatization of the petrous apex.
