Atlanoğlu Ş, Topuz MF. Surgical importance of the tympanic bone: multidetector computed tomography findings.
J Korean Assoc Oral Maxillofac Surg 2022;
48:149-154. [PMID:
35770355 PMCID:
PMC9247452 DOI:
10.5125/jkaoms.2022.48.3.149]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 04/02/2022] [Accepted: 04/19/2022] [Indexed: 11/10/2022] Open
Abstract
Objectives
To measure tympanic bone thickness (anterior-superior, anterior-inferior, and inferior wall), external ear canal length, and tympanomandibular distance that can be useful in cases that undergo tympanic bone resection.
Materials and Methods
The temporal computed tomography (CT) images of 349 patients were retrospectively evaluated. The anterior-inferior, anterior-superior, and inferior wall thicknesses; tympanomandibular distance; and external auditory canal (EAC) bone canal length were measured from the narrowest part of the canal. The shapes of the EAC in the coronal and sagittal planes were also examined.
Results
The numbers of female and male patients were similar, and the mean age was 49.45±13.95 years. The anterior-superior, anterior-inferior, and inferior wall thicknesses were 1.92±0.60, 2.54±0.74, and 9.16±2.20 mm, respectively. The anterior-superior and anterior-inferior wall thicknesses and canal lengths were greater on the right side (P<0.001). All measurement values were higher in males, except right tympanomandibular distance (P<0.05). A non-significant negative correlation was found between the age of the participants and the left anterior-inferior wall and tympanomandibular distance on both sides. Intra-observer agreement was high for all measurements. We observed four main shapes in the external ear canal in the coronal plane Type 3, Type 2, Type 1, and Type 4 in order of frequency on the right, and Type 2, Type 3, Type 1, and Type 4 on the left. In the sagittal plane, we detected three shapes oval (74.4%), triangular (16.3%), and round (9.4%).
Conclusion
The anterior wall thicknesses and tympanomandibular distance should be measured on preoperative temporal bone CT to safely perform tympanic bone anterior resection, which is required in some otological procedures, and also to prevent temporomandibular joint damage.
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