USMLE® Step 1 style questions USMLE
USMLE® Step 2 style questions USMLE
A 30-year-old man comes to the office to evaluate right ear pain for the past three months. The pain is constant, dull, and associated with recurrent right-sided jaw pain and headache. The pain worsens throughout the day and with chewing. He hears a “cracking sound” while eating. The patient’s partner says that he grinds his teeth at night. Vital signs are within normal limits. Physical examination shows limited jaw opening and muscle spasms over the lateral right face. Otoscopic examination is within normal limits. Which of the following nerves contributes to this patient’s ear pain?
Content Reviewers:Rishi Desai, MD, MPH, Tanner Marshall, MS
When people are stressed they sometimes clench their jaw and grind their teeth.
This is called bruxism. Bruxism can happen day or night, with episodes sometimes lasting a few days, but other times going on for months.
Usually, it’s long-term teeth-grinding that can really cause problems.
Grinding the top and bottom teeth together can lead to something called dental abfraction.
This loss of tooth structure and general dental attrition occurs as the biting surfaces of each tooth are flattened out.
Over time, this can wear away the protective outer surface of the tooth, called the enamel, revealing the much more sensitive dentin below, leading to tooth hypersensitivity and increased risk of cavities.
In its most severe forms, bruxism can even cause teeth to fracture, loosen, or even fall out, and the constant grinding can also cause damage to existing dental work like crowns and fillings.
Occasionally people with bruxism bite their tongue as well, which can lead to a crenated or scalloped tongue marked by tooth-shaped indentations.
People with bruxism sometimes have canker sores from chewing their lips and inner cheeks, too.
Bruxism can also lead to temporomandibular joint disorder, or TMJ, which involves the temporalis, masseter, and pterygoid muscles; these muscles help with chewing by working together to move the mandible or jawbone.
Clenching these muscles over and over can be tiring and painful, particularly in the preauricular area right in front of the ear, causing headaches around the temples.
Bruxism can also lead to inflammation of the periodontal ligaments, the tiny ligaments that attach each tooth to the bony socket they’re nestled in, which can make chewing quite painful.
Finally the repeated clenching can cause the chewing muscles to hypertrophy or grow, which worsens the grinding action by making it more powerful and therefore more painful.
Bruxism is an unconscious behavior.
When it happens at night it’s called “sleep bruxism” or “nocturnal bruxism”.
Typically, sleep bruxism is first noticed by family or friends who hear the clicking, grating sounds the person makes as they grind their teeth during sleep.