Temporomandibular joint dislocation

The jaw sometimes dislocates after enthusiastic laughing, chewing or kissing.

Palpate to check there has not been a fracture.

Types of dislocation

• the mandible usually dislocates anteriorly, and subluxes when the jaw is opened wide
• other dislocations imply the presence of a fracture and require referral to a surgeon

Dislocation is often a chronic problem and associated with temporomandibular joint dysfunction.

If dislocation is not obvious, then consider other conditions, such as:

• fracture
• hemarthrosis
• closed lock of the joint meniscus
• myofascial pain.

Clinical features:

• severe pain at TMJ and over masseter muscle
• the jaw is pushed forward from its normal position
• the patient cannot bite the teeth together
• dislocation on one side only causes asymmetrical deviation of the chin
• bilateral dislocation causes the jaw to protrude
• the patient has difficulty speaking (2)
• severe pain anterior to the ear (2)
• a depression can be seen or felt in the preauricular area (2)

Reference:

• (1) N Lawrence et al, HB Emergencies in Gen Pract 2e, 1997
• (2) Jaw dislocation. National center for emergency medicine informatics.2008