ENT - September 2020 - 533

Lee et al

533

Figure 1. Categorization of shapes of OEAC based on Mahboubi's classification in 2012: (A) hourglass, (B) conical, (C) cylindrical, (D) reverse
conical (A * D: images are from axial sections); (E) hourglass shape (E: image is from coronal section). OEAC indicates osseous external
auditory canal.

hospitals with different protocols or with low resolution quality
were also excluded.
As to the second cohort (the control group), patients who
also received HRCT studies of temporal bone between 2011
and 2013 due to certain indication other than COM and the
exclusion criteria mentioned earlier were included. They all
had normal anatomic structure of bilateral ears without any
active disease proven by HRCT of temporal bone.

Measurements of OEAC Dimension

All the CT scans were obtained using Philips Brilliance
40-slice CT scanners. Axial and coronal plane CT images of
the temporal bones were evaluated, with the axial images taken
parallel to the ground. The slice thickness was 1 mm, and the
interval thickness was 0 mm.

We separately measured the OEAC dimension at 2 sections of
the axial and the coronal view. In the hourglass group, the first
section (which we defined as the isthmus section) was used to
measure the distance from bone to bone at the isthmus section
on axial (Figure 2) and coronal views. The second section
(which we defined as the annular or membranous section) was
used to measure the maximal distance from bone to bone at
the tympanic membrane section. However, in the nonhourglass group (including the groups of conical, ovoid, reverse
conical, and cylindrical shapes), the first section was standardized and replaced by measuring the distance from bone to
bone at the midcanal section (Figure 3). That is because there
was no obvious isthmus that could be identified in the nonhourglass group.

Classification of OEAC Shape

Statistical Analysis

The shape of OEAC was evaluated by axial and coronal images
of HRCT. We classified all the patients into 5 groups by their
OEAC shape (Figure 1) based on Mahboubi's anatomic study
in 20125-conical, ovoid, reverse conical, hourglass, and
cylindrical shapes.

The paired t test was used to analyze the differences in OEAC
dimension between the 2 sides of ears of the same people
within the COM and normal groups; the Student t test was used
to analyze the differences in OEAC dimension between different groups. A P value <.05 indicated statistical significance.

Imaging of the OEAC



ENT - September 2020

Table of Contents for the Digital Edition of ENT - September 2020

The Creation of a Sustainable Otolaryngology Department in Malawi Nathan Douglas Vandjelovic, Eric Masao Sugihara, Wakisa Mulwafu, and David Nathan Madgy
Hazardous Grilling Due to Wire Brushes Nima A. Vahidi, Brenna A. Keane, Paul J. Whalen, and Anita Jeyakumar
Guns n’ Noses: Endoscopic Removal of an Air-Gun Pellet Retained in the Frontal Sinus Dylan A. Levy, Andrew Y. Lee, Waleed M. Abuzeid, and Nadeem A. Akbar
Vitamin D Status in Egyptian Children With Allergic Rhinitis Khaled Saad, Abobakr Abdelmoghny, Mohamed Diab Aboul-Khair, Yasser Farouk Abdel-Raheem, Eman Fathalla Gad, Ahmed El-Sayed Hammour, Bahaa Hawary, Asmaa M. Zahran, Mohamd A. Alblihed, and Amira Elhoufey
Pediatric Epistaxis and Its Correlation Between Air Pollutants in Beijing From 2014 to 2017 Ying-Xia Lu, Jie-Qiong Liang, Qing-Long Gu, Chong Pang, and Chun-Lei Huang
Otomycosis With Tympanic Membrane Perforation: A Review of the Literature Petros Koltsidopoulos and Charalampos Skoulakis
Simultaneous Bilateral Same-Day Endoscopic Myringoplasty Using Tragal Cartilage From One Ear Baklaci Deniz, Kuzucu Ihsan, Guler Ismail, Kum Rauf Oguzhan, and Ozcan Muge
A Preliminary Report on the Investigation of Prestin as a Biomarker for Idiopathic Sudden Sensorineural Hearing Loss Changling Sun, Xiaolin Xuan, Zhi Zhou, Yuan Yuan, and Fei Xue
A Retrospective Study to Identify the Relationship Between the Dimension of Osseous External Auditory Canal and Chronic Otitis Media Yi-Fang Lee, Pei-Yin Wei, Chia-Huei Chu, Wen-Huei Liao, An-Suey Shiao, and Mao-Che Wang
Investigation of the Effectiveness of Surgical Treatment on Respiratory Functions in Patients With Obstructive Sleep Apnea Syndrome Burak Kersin, Murat Karaman, Engin Aynacı, and Ahmet Keles
Changing Trends of Color of Different Laryngeal Regions in Laryngopharyngeal Reflux Disease Chen Du, Paige Thayer, Yan Yan, Qingsong Liu, Li Wang, and Jack Jiang
ENT - September 2020 - Intro
ENT - September 2020 - Cover1
ENT - September 2020 - Cover2
ENT - September 2020 - 489
ENT - September 2020 - 490
ENT - September 2020 - 491
ENT - September 2020 - 492
ENT - September 2020 - 493
ENT - September 2020 - 494
ENT - September 2020 - 495
ENT - September 2020 - 496
ENT - September 2020 - 497
ENT - September 2020 - 498
ENT - September 2020 - 499
ENT - September 2020 - 500
ENT - September 2020 - The Creation of a Sustainable Otolaryngology Department in Malawi Nathan Douglas Vandjelovic, Eric Masao Sugihara, Wakisa Mulwafu, and David Nathan Madgy
ENT - September 2020 - 502
ENT - September 2020 - Hazardous Grilling Due to Wire Brushes Nima A. Vahidi, Brenna A. Keane, Paul J. Whalen, and Anita Jeyakumar
ENT - September 2020 - 504
ENT - September 2020 - Guns n’ Noses: Endoscopic Removal of an Air-Gun Pellet Retained in the Frontal Sinus Dylan A. Levy, Andrew Y. Lee, Waleed M. Abuzeid, and Nadeem A. Akbar
ENT - September 2020 - 506
ENT - September 2020 - 507
ENT - September 2020 - Vitamin D Status in Egyptian Children With Allergic Rhinitis Khaled Saad, Abobakr Abdelmoghny, Mohamed Diab Aboul-Khair, Yasser Farouk Abdel-Raheem, Eman Fathalla Gad, Ahmed El-Sayed Hammour, Bahaa Hawary, Asmaa M. Zahran, Mohamd A. Alblihed, and Amira Elhoufey
ENT - September 2020 - 509
ENT - September 2020 - 510
ENT - September 2020 - 511
ENT - September 2020 - 512
ENT - September 2020 - Pediatric Epistaxis and Its Correlation Between Air Pollutants in Beijing From 2014 to 2017 Ying-Xia Lu, Jie-Qiong Liang, Qing-Long Gu, Chong Pang, and Chun-Lei Huang
ENT - September 2020 - 514
ENT - September 2020 - 515
ENT - September 2020 - 516
ENT - September 2020 - 517
ENT - September 2020 - Otomycosis With Tympanic Membrane Perforation: A Review of the Literature Petros Koltsidopoulos and Charalampos Skoulakis
ENT - September 2020 - 519
ENT - September 2020 - 520
ENT - September 2020 - 521
ENT - September 2020 - Simultaneous Bilateral Same-Day Endoscopic Myringoplasty Using Tragal Cartilage From One Ear Baklaci Deniz, Kuzucu Ihsan, Guler Ismail, Kum Rauf Oguzhan, and Ozcan Muge
ENT - September 2020 - 523
ENT - September 2020 - 524
ENT - September 2020 - 525
ENT - September 2020 - 526
ENT - September 2020 - 527
ENT - September 2020 - A Preliminary Report on the Investigation of Prestin as a Biomarker for Idiopathic Sudden Sensorineural Hearing Loss Changling Sun, Xiaolin Xuan, Zhi Zhou, Yuan Yuan, and Fei Xue
ENT - September 2020 - 529
ENT - September 2020 - 530
ENT - September 2020 - 531
ENT - September 2020 - A Retrospective Study to Identify the Relationship Between the Dimension of Osseous External Auditory Canal and Chronic Otitis Media Yi-Fang Lee, Pei-Yin Wei, Chia-Huei Chu, Wen-Huei Liao, An-Suey Shiao, and Mao-Che Wang
ENT - September 2020 - 533
ENT - September 2020 - 534
ENT - September 2020 - 535
ENT - September 2020 - 536
ENT - September 2020 - Investigation of the Effectiveness of Surgical Treatment on Respiratory Functions in Patients With Obstructive Sleep Apnea Syndrome Burak Kersin, Murat Karaman, Engin Aynacı, and Ahmet Keles
ENT - September 2020 - 538
ENT - September 2020 - 539
ENT - September 2020 - 540
ENT - September 2020 - 541
ENT - September 2020 - 542
ENT - September 2020 - Changing Trends of Color of Different Laryngeal Regions in Laryngopharyngeal Reflux Disease Chen Du, Paige Thayer, Yan Yan, Qingsong Liu, Li Wang, and Jack Jiang
ENT - September 2020 - 544
ENT - September 2020 - 545
ENT - September 2020 - 546
ENT - September 2020 - 547
ENT - September 2020 - 548
ENT - September 2020 - 549
ENT - September 2020 - 550
ENT - September 2020 - 551
ENT - September 2020 - 552
ENT - September 2020 - Cover3
ENT - September 2020 - Cover4
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