Otological symptoms and audiometric findings in patients with temporomandibular disorders: Costen's syndrome revisited

Objective: Otological symptoms (otalgia, subjective hearing loss, blocked ear sensation, tinnitus and vertigo) associated with temporomandibular disorders are documented features of Costen's syndrome. However, the origin of these symptoms and the causes of hearing loss are unknown. This study aimed to characterise hearing loss in a large number of patients with temporomandibular disorders. The causes of these symptoms were explored in patients with otological symptoms and normal audiometric findings. Methods: A prospective case study and literature review were performed. The audiometric features of 104 temporomandibular disorder patients were compared with those of 110 control participants. Results: A large proportion of temporomandibular disorder patients had several otological symptoms. Twenty-five per cent of unilateral or bilateral temporomandibular disorder patients had either unilateral (ipsilateral) or bilateral hearing loss; respectively, which was usually mild (p = 0.001). Hearing loss was predominantly sensorineural. Conclusion: The main cause of otological symptoms (apart from otalgia) and of audiometric findings in temporomandibular disorder patients is postulated to be an altered middle-ear to inner-ear pressure equilibrium.