A Case of Spontaneous Temporomandibular Joint Herniation into the External Auditory Canal with Clicking Sound
A 53-year-old man came to the Otorhinolaryngology department as an outpatient in September 2011 for the chief complaint of clicking tinnitus on the left. The patient had a past medical history of arrhythmia and heart valve disease but there was no history of trauma or surgery which could have led to tinnitus. Since July 2008, he had received rehabilitation treatment due to cerebral infarction in the middle cerebral artery zone. The clicking tinnitus started suddenly 3 weeks before he visited the hospital, mostly during mastication and when opening and closing his mouth. During the 3 weeks, the clicking tinnitus happened without strength change and without other otologic symptoms such as otalgia and otorrhea. In the otoscopic examination, the tympanic membrane was normal but there was slight protrusion of the soft tissue, originating from the anterior wall of the left EAC. This protrusion was observed when the mouth was closed and if it was open, the protrusion retracted (). The clicking sound that was heard in the left ear of the patient was also heard by the observer when he put a stethoscope on the EAC of the patient when the mouth was opened and closed.\nThe patient did not feel uncomfortable in his daily life from the clicking tinnitus, and the Tinnitus Handicap Inventory (THI) score was 18. According to the pure tone audiometry, the air conduction average threshold value (4 division method) was 23 dB on the right and 22 dB on the left while the average threshold value from bone conduction audiometry was 21 dB and 20 dB respectively. On the impedance test, both sides were A type. We conducted a tinnitogram but the patient complained of just clicking and we failed to find the exact strength and frequency.\nAccording to his otologic history, he had clicking at the time of mastication. Pure tone audiometry also failed to detect sensorineural or conductive hearing loss while the otoscopy found an anterior wall protrusion at the left EAC, and so TMJ herniation was suspected. Therefore, we conducted TMJ X-ray and temporal computed tomography. From the TMJ X-ray, we could see a left temporomandibular joint herniation at the time of mastication (), and the temporal bone computed tomography detected a 6 mm bony defect in the left EAC anterior wall and subsequent soft tissue herniation (). At the right EAC, there was no bony defect or other unusual findings. The left clicking tinnitus complained by the patient was revealed to occur from TMJ tissue herniation into the EAC at the time of mastication. Therefore, we considered surgical treatment for the left EAC anterior wall defect but the patient refused surgery because he felt uncomfortable with surgical treatment as he was receiving rehabilitation for cerebral infarction, and furthermore, he did not suffer much inconvenience from the clicking tinnitus. Thus, the authors treated him with an anxiolytic and muscle relaxant for 2 weeks, after which we could not see any change in loudness of the tinnitus (according to the patient) and emotional reaction. Now, the authors are observing the progress of the clicking tinnitus.