Am J Otolaryngol Head Neck Surg | Volume 6, Issue 4 | Research Article | Open Access

External Auditory Canal Angle and Cerumen Accumulation

Rafiee F1, Hoseinyazdi M2, Motaghi M2 and Yousem DM2*

1Massachusetts General Hospital, USA
2Department of Radiology and Radiological Science, Johns Hopkins Medical Institution, USA

*Correspondance to: David M. Yousem 

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Objectives: Cerumen in the External Auditory Canal (EAC) is a common incidental finding on head CT scans. However, the factors that predispose to Cerumen Accumulation (CA) have not been studied through imaging. We hypothesized that a steeper inferior angulation of the EAC would allow greater drainage of cerumen and decrease the rate of CA. Materials and Methods: 303 CT scans performed over three days were reviewed to determine CA presence and the angulation of the EAC on coronal bone windows. The angle was measured from the plane of the roof of the EAC to the otic labyrinth to the midpoint of the junction between the bony and cartilaginous EAC. CA was graded 0 (no cerumen), 1 (less than 50% EAC filled), 2 (51%- 99% filled) or 3 (complete opacification). Results: CA was present in 87/303 (28.7%) patients and bilateral in 35/87 (40.2%). 122/603 (20.2%) ears showed CA. The mean angle of 24.2 ± 6.0 degrees in patients without CA was significantly higher than those with CA (22.02 ± 5.2) (p=0.0004). Logistic regression showed that for each degree increase in the angle of the EAC, the odds of having CA decreased by 6.5% (OR=0.935, p=0.002). In the 34 patients who had unilateral CA but both angles measured, the mean angle was lower in the CA ear compared to without CA (p=0.002). The angle also inversely impacted the grade of CA. Intra observer and inter observer measurement concordance was moderate to excellent. Conclusion: A larger inferior angulation of the EAC is associated with a lower rate of CA.


External auditory canal; Cerumen; Computed tomography; Impaction


Rafiee F, Hoseinyazdi M, Motaghi M, Yousem DM. External Auditory Canal Angle and Cerumen Accumulation. Am J Otolaryngol Head Neck Surg. 2023;6(4):1239..

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