TMJ Dislocation

Overview

What is TMJ Dislocation?

TMJ dislocation occurs when the mandibular condyle moves out of its normal position in the glenoid fossa and becomes locked anterior to the articular eminence. This results in the inability to close the mouth. Dislocation can be unilateral or bilateral and may become recurrent in some individuals.

• Jaw becomes stuck in open position
• Can be unilateral or bilateral
• More common in women
• May become recurrent in susceptible individuals
• Requires prompt reduction

Overview of the Condition

Dislocation typically occurs when the mouth is opened wide, and the condyle slips forward past the articular eminence. Muscle spasm then prevents it from returning to position. This is different from disc displacement and requires manual reduction. Chronic or recurrent dislocations may need surgical intervention.

References

• NCBI - TMJ Dislocation
• AAOMS - TMJ Resources

Symptoms and Causes

Symptoms

• Inability to close the mouth
• Lower jaw stuck forward
• Severe pain in front of ears
• Drooling (unable to swallow properly)
• Difficulty speaking
• Visible or palpable depression in preauricular area
• Anxiety and distress
• Unilateral dislocation causes deviation to opposite side

Causes

• Wide yawning
• Prolonged dental procedures
• Intubation for anesthesia
• Seizures
• Vomiting
• Trauma to the jaw
• Dystonic reactions to medications
• Joint hypermobility
• Previous dislocations (predisposes to recurrence)

Diagnosis and Treatment Options

Diagnosis

• Clinical presentation is usually diagnostic
• Inability to close mouth with jaw protruding
• Palpation of empty glenoid fossa
• Radiograph to confirm and rule out fracture
• CT if fracture suspected or reduction difficult
• Assessment for recurrence history

Treatment Options

• Manual reduction (primary treatment)
• Muscle relaxants or sedation if needed
• Local anesthesia to relax muscles
• Barton bandage after reduction
• Surgical intervention for recurrent cases
• Botulinum toxin for recurrent dislocation

Non-Surgical Care

Manual Reduction

The primary treatment is manual reduction, which should be performed as soon as possible. Delay increases muscle spasm and makes reduction more difficult. Various techniques exist, with the traditional method involving downward and backward pressure on the lower molars.

Post-Reduction Care

1. Apply Barton bandage to limit opening
2. Soft diet for 1-2 weeks
3. Avoid wide yawning
4. NSAIDs for pain and inflammation
5. Apply ice to reduce swelling
6. Limit mouth opening
7. Follow up if recurrence occurs

Surgical Care

When is Surgery Needed?

Surgery is considered for recurrent dislocations that significantly impact quality of life and fail conservative management. Surgical options aim to either limit condylar movement or enhance the barrier to dislocation.

Surgical Options

• Eminectomy (removal of articular eminence)
• Augmentation of articular eminence
• Capsular plication (tightening)
• Myotomy of lateral pterygoid
• Botulinum toxin injection to lateral pterygoid
• Glenotemporal osteotomy

Anatomy and Affected Areas

Anatomy Overview

During normal opening, the condyle rotates and translates forward. In dislocation, the condyle moves completely anterior to the articular eminence and becomes trapped there. Muscle spasm, particularly of the masseter and lateral pterygoid, prevents spontaneous reduction.

Affected Structures

• Mandibular condyle
• Articular eminence
• Glenoid fossa
• Joint capsule and ligaments
• Muscles of mastication
• Articular disc

Frequently Asked Questions

Frequently Asked Questions

QuestionAnswerIs TMJ dislocation an emergency?It requires prompt treatment but is not life-threatening.Can I reduce it myself?Not recommended; improper attempts can cause injury.Why does my jaw keep dislocating?Joint laxity, previous injury, or anatomy may predispose to recurrence.Will it happen again?Recurrence is possible, especially with joint hypermobility.How do I prevent it?Avoid wide yawning, support jaw when opening wide.Does it damage the joint?Repeated dislocations may cause joint damage over time.

Prevention Tips

Prevention Strategies

• Avoid extreme wide mouth opening
• Support jaw when yawning
• Inform dentist of history before procedures
• Request breaks during long dental work
• Consider prophylactic measures if history of recurrence
• Be cautious during activities that require wide opening

Related Conditions

Related Conditions

• Joint hypermobility syndrome
• Ehlers-Danlos syndrome
• TMJ disc displacement
• TMJ subluxation
• Jaw fracture (must be ruled out)

Prognosis

Acute TMJ dislocation has an excellent prognosis with prompt reduction. Most patients recover fully with conservative management. Those with recurrent dislocations may need more aggressive treatment but can usually achieve good outcomes with appropriate intervention.