Temporomandibular joint disorders (TMD) are a group of musculoskeletal conditions that involve the temporomandibular joints, the masticatory muscles and all associated tissues [1]. Common signs and symptoms of TMD include temporomandibular joint or masticatory muscle pain, restricted mouth opening, clicking or crepitus of the temporomandibular joint, headache in the temporal region, otalgia, tinnitus, and hearing loss [2]. Numerous studies have reported a link between the aural symptoms and TMD [3-8]. However, TMD as a potential cause of otologic symptoms, in particular aural fullness, is often neglected in clinical practice by otolaryngologists. As a result, patients with aural fullness as the main or sole complaint could be misdiagnosed, leading to ineffective treatment and prolonged suffering. This study examined the presence of TMD and effectiveness of TMD treatment in 112 Chinese patients, who presented to the otolaryngology clinics for aural fullness and had been diagnosed and treated for otitis media or sensorineural hearing loss without positive results.

Aural fullness is a common aural complaint, the etiology of which is not clearly defined. Previous studies have suggested a link between aural fullness and somatosensory dysregulation [10]. However, many patients complaining of aural fullness cannot correctly define the origin of the symptom [11]. In otolaryngology practice, patients with aural fullness as the main or sole complaint could be misdiagnosed. This study enrolled 112 patients who presented for aural fullness to the Otolaryngology Department, PLA Army General Hospital, Beijing, China, between January 2010 and January 2015. Of the 112 patients, 90 had been diagnosed and treated for otitis media and 23 for sensorineural deafness. This is not surprising given that aural fullness is among the manifestations of these pathologies. However, none of patients showed improvement in aural fullness after receiving corresponding treatments, suggesting a non-otolaryngology origin of the symptom.

Further examination of these patients revealed signs of TMD, which involves the masticatory muscles, the temporomandibular joint and associated structures [2]. Common aural manifestations of TMD include restricted mouth opening, clicking or crepitus of temporomandibular joint, otalgia, tinnitus, hearing loss, etc. [3-7]. Based on the questionnaire results as well as data obtained from X-ray and/or CT scan of the temporomandibular joint, patients were diagnosed and further categorized according to the RDC/TMD [9]. The use of X-ray and CT scan in this study helps to reveal potential pathological changes in temporomandibular joint and associated structures. Interestingly, TMD patients with aural symptoms were reported to often have changes in middle ear impedance as shown by multiple frequency tympanometry [8]. However, all of the 112 patients enrolled in this study showed type A tympanometry, indicative of normal middle ear immittance. Further studies need to determine the relationship between TMD, middle ear immittance and aural fullness.

Patients were subsequently treated for TMD based on the disease category and responsiveness to therapy. Strikingly, 90.2% of the patients showed disappearance of or significant improvement in aural fullness, suggesting TMD as a cause of the aural fullness. TMD treatments are especially effective (94.1%) for improving aural fullness experienced in group I TMD (muscle disorders) patients. Among the different treatments, physiotherapy which includes heat therapy, acupuncture and massage is the most effective. To the author’s knowledge, there has been only one case report showing that ear fullness was successfully managed as a temporomandibular disorder [12]. The present survey represents the first to show with a large patient cohort that TMD treatment could successfully cure/improve aural fullness. Interestingly, TMD treatments are often ineffective of improving aural fullness in patients showing temporomandibular joint structural changes. It is worth noting that one limitation of this retrospective study is the lack of untreated control group. Considering the possible self-resolution of aural fullness in the long term, we cannot conclude on the exact percentage of patients in which TMD drives aural fullness. However, our data clearly suggest a link between aural fullness and TMD. It is not clear how TMD causes aural fullness, although it has been proposed that TMD patients with a clenching habit might have dysfunctional masticatory muscle and tensor tympani muscle, leading to aural fullness [12].

Based on the study, a diagnosis/treatment protocol could be proposed for patients with chief aural fullness complaint. Aural fullness arisen from otologic causes can usually be diagnosed by a holistic review of one’s medical history, symptoms, and results of pure tone audiometry, acoustic immittance screen, X-ray and/or CT scan. For example, Ménière’s disease-induced aural fullness is often associated with fluctuations tinnitus, dizziness and nausea. Earwax embolism can be seen by blocked external auditory canal. Otitis media can be detected by pure tone audiometry, acoustic immittance screen, X-ray and/or CT scan. If the patient has normal external auditory canal, eardrum and mastoid process, and shows type A tympanogram, TMD could underlie the aural fullness and should be further evaluated by commonly associated manifestations such as restricted mouth opening, clicking or crepitus of temporomandibular joint, etc.

In summary, this study establishes TMD as a potential cause of aural fullness and shows that TMD treatments are successful against aural fullness. Patients with aural fullness as the main or sole complaint should be examined for TMD. Once TMD is confirmed, physiotherapy, intra-articular injection of glucocorticoid and sodium hyaluronate, orthodontics and occlusal equilibration could be given in a sequential manner according to individual’s TMD category and responsiveness to therapy.