Relationship Between the Dimensions of the Osseous External Auditory Canal and Age in a Pediatric Population

By June 7, 2019

Watanabe, Chihiro1; Kubota, Toshinori1; Ito, Tsukasa1; Furukawa, Takatoshi1; Matsui, Hirooki1; Goto, Takanari1; Futai, Kazunori1; Kakehata, Seiji1
1 Department of Otolaryngology Head and Neck Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan.

We used a new image processing program, ImageJ, to objectively analyze the relationship between the dimensions of the osseous external auditory canal (OEAC) and age in a pediatric population. This data was used to determine whether a patient was indicated for transcanal ear endoscopic surgery (TEES).

–Study Design: Retrospective study.
–Setting: University hospital.
–Patients: 125 pediatric patients (18 years old or younger) who underwent ear surgery (TEES or MES) from February 2012 to December 2017.
–Intervention(s): ImageJ was used to analyze sagittal CT images to determine the OEAC smallest minimum Feret diameters; smallest maximum Feret diameters; and the length of the OEAC.

–Main Outcome Measure(s):We analyzed the OEAC dimensions, and the correlation between the OEAC dimensions and age based on a logistic regression analysis.
–Results: Data was collected for all 125 patients with smallest minimum Feret diameter ranging from 3.42 to 6.57 mm (mean: 4.75 mm) and exhibiting no significant age-related changes; the smallest maximum Feret diameter ranging from 5.99 to 11.38 mm (mean: 8.08 mm) and increasing slightly with age (r=0.20); and the length of the OEAC ranging from 0.5 to 10.08 mm (mean: 4.82 mm) and positively correlated with age (r=0.57). Data was also collected for 64 patients during a postoperative follow-up CT scan to determine changes over time and the results were similar to those of the entire 125-patient group.

The smallest minimum Feret diameter exhibits no significant age-related changes which underscores that TEES is indicated for even the youngest of patients.