Bilateral spontaneous temporomandibular joint herniation into the external auditory canal.

The clinical and radiological findings in the first case in the literature of spontaneous, bilateral and asymptomatic herniation of soft tissue from the temporomandibular joint into the anterior wall of the external canal are presented. With the patient's mouth closed, the herniations appeared as a dome-shaped swelling located on the anterior wall of each bony external auditory canal. With the patient's mouth opened, the dome-shaped swellings were retracted anteriorly, producing an invagination of the skin of the external canal at the site of the previous herniation. A high resolution CT scan of the temporal bones revealed that the soft tissue of both temporomandibular joints was protruding through a congenital dehiscence in the anterior wall of the tympanic bones.