A 25-year-old woman comes to the office due to right ear pain that has worsened over the past 2 months. The pain is dull and constant and waxes and wanes. It is worse when she chews hard foods such as steak or almonds. In addition to ear pain, her ear feels stuffy and has some ringing. The patient grinds her teeth at night and previously wore a dental guard, but it broke several months ago. Ear examination is normal. Which of the following nerves is most likely responsible for this patient's ear pain?

Question

A 25-year-old woman comes to the office due to right ear pain that has worsened over the past 2 months.  The pain is dull and constant and waxes and wanes.  It is worse when she chews hard foods such as steak or almonds.  In addition to ear pain, her ear feels stuffy and has some ringing.  The patient grinds her teeth at night and previously wore a dental guard, but it broke several months ago.  Ear examination is normal.  Which of the following nerves is most likely responsible for this patient's ear pain?

Quizplus · Accepted Answer

11ec160b_356f_4afa_9249_2f94eb8876a5_MD0001_00 This patient's presentation is most consistent with temporomandibular joint disorder (TMD). The underlying etiology of TMD is multifactorial and includes temporomandibular joint derangement (eg, jaw misalignment, jaw clenching/teeth grinding, trauma) and hypersensitivity of the mandibular nerve (CN V3). In addition to the classic symptoms of dull, waxing-and-waning face/jaw pain (worse with chewing) and clicking/popping noises with jaw movement, TMD can also present with ear-related symptoms (eg, ear pain, ear stuffiness, tinnitus). Many of these clinical findings are due to involvement of the mandibular nerve (CN V3), which is the largest branch of the trigeminal nerve. It supplies sensation to the temporomandibular joint, floor of mouth, anterior tongue, and lower part of the face. In addition, it contributes to the sensory innervation of the external auditory canal; therefore, TMD can present with ear pain that is referred from the jaw joint. Ear stuffiness may be related to hypersensitivity affecting the tensor tympani. Theories regarding tinnitus in TMD include the proximity of the muscles of mastication to the ear and central connections between nerve supply of the temporomandibular joint and the areas of the brain involved in hearing. (Choice A) The sensory component of the glossopharyngeal nerve (CN IX) carries general sensory information from the tonsils, pharynx, middle ear, and posterior third of the tongue; special sensory information (taste) from the posterior third of the tongue; and visceral sensory information from the carotid bodies and carotid sinus. (Choice B) The hypoglossal nerve (CN XII) carries general motor efferent information to the intrinsic and extrinsic muscles of the tongue. (Choice D) The auricular branch of the vagus nerve (CN X) conveys sensory information from the external auditory canal but is not thought to be involved in the pathogenesis of TMD. (Choice E) The vestibulocochlear nerve (CN VIII) carries only special sensory information (auditory and balance) from the inner ear. Educational objective: Temporomandibular joint disorder is associated with derangement of the temporomandibular joint and hypersensitivity of the mandibular nerve (CN V3). __________ References: Temporomandibular disorder: otologic implications and its relationship to sleep bruxism. (http://www.ncbi.nlm.nih.gov/pubmed/28966039) Temporomandibular disorder: an underdiagnosed cause of headache, sinus pain, and ear pain. (http://www.ncbi.nlm.nih.gov/pubmed/28145680)

A 25-Year-Old Woman Comes to the Office Due to Right