Atypical Earache Otomandibular Symptoms
There is a close relationship between disorders of the jaw/neck and symptoms of the ear. In one study of 344 patients, 60% of the patients with temporomandibular joint disorder (TMD) had ear symptoms.1 In another study of 400 patients, 42% had ear symptoms.2 Twenty-one of 28 patients had relief of tinnitus following orofacial pain therapy.3 The prevalence of non-otologic aural symptoms or referred otalgia in TMD patients varies from 3.5 to 42%.4 The prevalence of tinnitus is 15% in the general population. With TMD patients, this percentage escalates from 33% to 76%.5 The prevalence of vertigo in the general population is 5% and in the TMD population this percentage escalates from 40% to 70%6. The fullness in the ear and minor hearing loss have not have been adequately studied. Referred otalgia may account for as much as 50% of all ear pain complaints.7 Disc displacement was found to be present in the ipsilateral joint in all 53 patients with unilateral tinnitus.8 In a clinical case report, a 38-year old female with confirmed TMD underwent an arthroscopic procedure; upon awakening she had ear pain, saline in her middle ear, and hearing loss without ear canal perforation.9
An understanding of the relationship between the jaw/neck pathologies and ear requires reviewing today’s anatomical, neuromuscular, and central sensitization science. The anatomical concepts relate the direct connection of the jaw joint and trigeminal structures to the ear. The neuromuscular concept relates referral patterns of specific muscles of the trigeminal and cervical systems to the ear. Central sensitization incorporates how several different sources of pain (undiagnosed pain, ‘piggy-back’ pains, frequent recurrent pains, and chronic pains) induce anatomical, neurochemical, and physiological changes to the nervous system. The chronic pain that evolves from these mechanisms changes the visual diagnostic world of acute pain to the “bio-detective” world of orofacial pain and may confound diagnoses.
The atypical earache patient’s differential diagnostic list should include articular disc disorders (TMJ/TMD), myofascial pain dysfunction (chewing muscle pain), cervical muscle dysfunction, or cancer. Even though the ear is the source of most ear pain, the atypical earache is a fairly common adult occurrence in medical practices. Atypical earaches commonly are in the chronic pain arena with multiple causes and often involve central sensitization. If the physician had some way of knowing it was only a muscle problem the patient could be referred to a dentist for therapy. If the diagnosis is unknown at the time of referral, it may be a better choice to refer to an orofacial pain specialist trained in all the atypical ear pains. The atypical earache poses a management problem. All too often, after ruling out the ear as the source of the pain — an important step in the diagnostic journey — the patient is given no direction on the next step to complete the diagnosis. Some patients report that they have been told that they are “just a stressed-out female” since the pain is aggravated by stress. Occasionally, a physician might just pass it off as TMD without an exam due to the statistics of occurrence. Some refer the patient to an ENT for a second opinion on the ear as the source of the pain. In a busy practice where the typical doctor has about 12.5 minutes with the patient, it is difficult to correctly diagnose or refer the patient to the appropriate specialist.
The following clinical case illustrates the risks in not pursuing a differential diagnosis for an atypical earache:
A patient complained of moderate, deep aching pain in her left ear with one or more of following symptoms: tinnitus, vertigo, fullness in the ear, or minor hearing loss. The patient had little or no inflammation of the tympanic membrane. She complained that chewing, yawning, opening wide, and stress aggravated the pain. Since the pain seemed not to be associated with the ear, the attending physician made a casual comment that it might be TMD. However, a referral to an orofacial pain specialist was not made. The patient, feeling that her complaint was a benign problem, went home instead of seeking the appropriate consultation. The left ear pain worsened and she finally went to an orofacial pain specialist. Months later, this pain was diagnosed as a cancer in the pterygoid fossa.
The anatomical relationship between the jaw/neck and ear is seen by examining the skull and reviewing the close proximity of the two adjacent structures. The “wiring of the skull” is much more complex and convoluted than in the rest of the body, which makes it difficult for the brain to discriminate between the ear and jaw joint. The jaw joint is separated by a thin window of bone to the mid-brain and a thick bone to the adjacent ear canal.10 The retrodiscal tissues of the jaw joint attach up and down the ear bone with the blood and nervous tissues in the lower and middle tissues. The upper compartment of retrodiscal tissue attaches elastin from the tympanic plate bone to the meniscus (disc) of the superior head of the lateral pterygoid. The elastin retracts the disc from the 2 o’clock position on opening back to the 11 o’clock position on closure. Also, the elastin resists condylar dislocation or excessive translation. This elastin opposes the eccentric pull of the superior head of the lateral pterygoid in front of the disc to continually keep the disc directly interposed between the two convex surfaces of bone at maximum vector of force. In 1983, Dr. Parker Mahan found that the Superior lateral pterygoid muscle contracts on closing11 as the condyle moves posteriorly. The disc sits in between the convex surfaces in a bow tie configuration when anatomically correct. The disc is connected to the condyle by two-bucket handle ligaments on the lateral and medial sides of the joint. The medial aspect of the joint is associated with the medial disc ligament, the anterior malleolar ligament, and the sphenomandibular ligament. The medial aspect of the condyle has no capsule, but is a blending of different tissues.12
The second way the jaw joint and ear are connected is through a common nerve distribution, the auriculotemporal nerve. This nerve supplies both the lateral surface of the meatus of the ear and all the innervation of the jaw joint.10 This wiring commonality is one of the ways pain from the joint may be referred to the ear. In the world of acute pain, the site of the pain is the source of the pain, but in the chronic pain world this is not always true. Whether it is known exactly how this referral happens scientifically, it does happen clinically — especially with chronic pain pathologies.