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Spontaneous Temporomandibular Joint Herniation Into the External Auditory Canal Through a Persistent Foramen Tympanicum (Huschke): Radiographic Features

Nakasato, Tatsuhiko MD, PhD*; Nakayama, Tetsuo MD, PhD*; Kikuchi, Koyo MD*; Ehara, Shigeru MD, PhD*; Ohtsuka, Hisashi MD, PhD; Fukuda, Koji MD, PhD; Sato, Hiroaki MD, PhD

Journal of Computer Assisted Tomography:
doi: 10.1097/RCT.0b013e318272ef04

Abstract: Persistent foramen tympanicum (Huschke) is an anatomical variation located in the anteroinferior portion of the external auditory canal. We present a case of symptomatic temporomandibular joint (TMJ) herniation into the external auditory canal though an enlarged osseous defect. The herniated retrodiscal TMJ tissue moved backward when the patient’s mouth was closed, and forward, when opened. Magnetic resonance imaging findings were useful for differentiating TMJ herniation from salivary fistula caused by an ectopic salivary gland.

Author Information

From the Departments of *Radiology and †Otolaryngology-Head and Neck Surgery, Iwate Medical University School of Medicine, Morioka, Iwate, Japan.

Received for publication August 29, 2012; accepted September 5, 2012.

Reprints: Tatsuhiko Nakasato, MD, PhD, Department of Radiology, Iwate Medical University School of Medicine, 19-1 Uchimaru, Morioka 020-8505, Japan (e-mail:

This study has no sources of funding.

The authors have no conflicts of interest to declare.

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© 2013 Lippincott Williams & Wilkins, Inc.