USMLE® Step 1 style questions USMLE
A 21-year-old woman comes to the office, two days after attending a week-long music festival, because of intense facial and jaw pain. She says she had taken ecstasy multiple times during the music festival and also that she has had trouble sleeping over the past two days and has been feeling depressed. Physical examination shows no abnormalities. Which of the following is the most likely cause of the patient’s facial pain?
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.
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.