Why TMJ Can Cause Hearing Loss
The temporomandibular joint is very close to your ear. When you find the joint, you’ll see it’s just below and behind your ear. However, the connection is more than just proximity; there are close functional links between the jaw and the ear.
The joint’s name, ‘temporomandibular’, partly comes from the ‘temporal bone’, which surrounds the middle and inner ear. In addition, two tiny bones in the middle ear that help with hearing have evolved from jaw joint bones in reptiles. These bones and associated muscles still retain connections to the jaw joint. Regarding hearing loss, the muscle of most significant concern is the tensor tympani.
What Is the Tensor Tympani?
The tensor tympani is a small muscle in the ear. Its job is to steady the eardrum in response to loud noises. This reduces the vibration of the eardrum, reducing the amount of sound that passes from the eardrum to the hearing mechanism, dampening the sound you hear.
The most common sound of the tensor tympani muffles is your chewing. The tensor tympani also helps to open the eustachian tubes, which allow the ear to equalize pressure.
How TMJ Can Affect the Tensor Tympani
The relationship between TMJ and the tensor tympani muscle in the ear is intricate. Let’s break down the potential effects:
- Muscle Tension: TMJ can lead to tension in the head, neck, and jaw muscles. This tension can sometimes cause the tensor tympani to tense up. For instance, you might notice this when yawning or stretching your neck. This tension can produce a low sound, which you might hear if you focus on it. You might even feel a vibration if you place your hand over your ear, especially when the muscles are contracted.
- Impact on Hearing: When the tensor tympani muscle is tensed, it can make it harder for sounds to reach your middle or inner ear. This can lead to a reduction in hearing. Additionally, chronic tension in this muscle can result in ear pain.
- Trigeminal Nerve Connection: The tensor tympani is controlled by the trigeminal nerve, which also controls the jaw muscles. In people with TMJ, frequent tension in the jaw muscles due to behaviors like clenching or grinding can activate the tensor tympani. This can lead to hearing loss and ear pain.
- Eustachian Tube Function: TMJ might also interfere with the tensor tympani’s ability to open the eustachian tubes. This can lead to a buildup of pressure in the ear, resulting in a feeling of fullness, ear pain, and reduced hearing.