Introduction: The tympanic bone (TB) is 1 of the 4 essential parts of the temporal bone, located on its lateral-inferior aspect. It plays a pivotal role in forming the bony part of the external auditory canal, facilitating the transmission of sound to the middle ear. Objective: The current study aims to underline the surgical importance of the TB and its role as a key structure in lateral skull-base surgery, particularly the infratemporal fossa approach type A and removal of the TB during the surgical management of tympanojugular paraganglioma (TJP). Materials and Methods: In this study, we examined 20 formalin-prepared temporal bones to highlight the significant anatomical importance of the tympanic portion and its association with the styloid process in TJP surgery. Furthermore, a comprehensive MEDLINE (PubMed) search was conducted using the MeSH term (tympanic bone). Results: The minimum, maximum, and average thicknesses of the TB were 9.3 mm, 12.2 mm, and 10.6 mm, respectively. Whereas the length of the styloid process ranged from 29 mm to 52 mm, with a mean measurement of 43 mm. Among the 272 TJP cases operated on at our center, there were (26%) C1, (49%) C2, (22%) C3, and (3%) C4 cases according to the modified Fisch classification. TB infiltration was evident in virtually all C3 and C4 cases, approximately 70% of C2 tumors, and about 40% of C1 tumors. Conclusion: Although the TB is rarely discussed explicitly as a distinct structure in the literature, it plays a crucial role in many otologic and lateral skull-base procedures. These surgeries frequently require the partial or complete removal of the TB to access the hypotympanum and the internal carotid artery. A meticulous study of high-resolution computed tomography scans, especially coronal sections, is essential for understanding the detailed anatomy of TB.
Grinblat et al. (Fri,) studied this question.