Jaw dislocation

Disease Description (Causes and Symptoms)

• Definition: Luxation of the mandible is a condition in which the condyle (articular disc or articular process) of the mandible (lower jawbone) moves anteriorly (or, rarely, laterally) beyond the articular eminence, making normal mouth closure impossible.
• Causes/Pathophysiology: Predisposing factors include laxity of the joint capsule and ligaments, anatomical features of the joint structure (such as a shallow mandibular fossa), transverse-force trauma, and excessive mouth opening (yawning, laughing widely, or prolonged opening during dental treatment, endoscopy, etc.). Recurrent dislocation may develop into habitual (recurrent) dislocation when there is repetitive stress or connective tissue abnormality.
• Main symptoms: Sudden difficulty opening or closing the mouth (inability to close the mouth), severe pain, malocclusion (abnormal bite), difficulty swallowing and speaking, drooling, facial asymmetry (in chronic cases), headache, and difficulty chewing.

Treatment Methods

• Acute treatment (initial management)

  • Manual reduction: This is the first method attempted. When possible, the doctor pushes the lower jaw back into its original position after administering analgesics and muscle relaxants. If necessary, it is performed under sedation or general anesthesia.
  • Pain control: NSAIDs, short-term muscle relaxants (e.g., sedative medications), and local anesthesia as an adjunct.
  • Concurrent imaging: Before and after reduction, X-rays (panoramic radiography and plain X-rays) or CT may be used to assess bone structures and complications.

• Conservative treatment (after reduction)

  • For a short period (2–3 days or as directed by the doctor), immobilization of the jaw (with a lightly applied elastic bandage or jaw support), soft foods, and limitation of mouth opening.
  • Gradual range-of-motion exercises and physical therapy (joint stabilization and muscle strengthening).
  • If the risk of recurrence is high, conservative methods (intraoral devices [splints]) may be considered.

• Treatment for recurrent (habitual) dislocation

  • Conservative attempts: Intraoral devices (orthodontic appliances), physical therapy, and behavior modification (avoiding wide mouth opening).
  • Nonsurgical procedures: Autologous blood injection around the joint (to induce adhesion) and botulinum toxin injection (to relieve hypertonicity of the temporomandibular muscles) may be used in some patients.
  • Surgical treatment (for recurrent dislocation or failure of conservative treatment): Eminectomy, articular fossa surgery (eminence augmentation/eminoplasty), joint capsule and ligament suturing (capsulorrhaphy/ligament repair), joint replacement, joint corrective surgery, and others. The choice of surgical method is determined by an oral and maxillofacial surgery department or oral and maxillofacial surgeon based on the cause, anatomical findings, and the patient’s condition.

• Precautions (during/after treatment)

  • Do not attempt forceful reduction (risk of muscle or joint injury). Check for bleeding disorders and use of anticoagulants.
  • Immediately after reduction, avoid excessive mouth opening and chewing, and maintain immobilization and a soft-food diet for the instructed period.
  • If dislocation recurs, seek early referral to a specialist (to prevent recurrence and permanent deformity).

• Complications

  • Chronic joint problems (arthritis and joint dysfunction), facial asymmetry and malocclusion, and, rarely, direct or indirect injury to the joint space (articular cartilage rupture) and nerve injury during surgery.

Checklist Before an Outpatient Visit (Including Example Questions)

• Items and information to prepare

  • A list of currently used medications (especially anticoagulants, antiplatelet agents, sedatives, and muscle relaxants)
  • A history and number of previous jaw dislocations and the mechanism of occurrence (yawning, trauma, during treatment, etc.)
  • Recent photographs (the appearance of the face during dislocation) or videos taken when symptoms occurred, if available
  • Copies of previous test results (panoramic radiography, CT, MRI, etc.)
  • Records of when symptoms began, their duration, pain severity (pain score), and changes in eating, speaking, and swallowing
  • Allergies (including anesthetics), whether there is a bleeding disorder, and the possibility of pregnancy

• Items to check at the outpatient visit (self-check by the person seeking consultation)

  • Whether you can currently close your mouth (possible/impossible)
  • Whether dislocation recurs frequently and whether any action was taken during the most recent dislocation
  • The location and intensity of pain and whether there are signs suggestive of fever or infection
  • A history of prolonged mouth opening during recent dental treatment, endoscopy, surgery, or other procedures

Examples of General Questions to Ask the Doctor

• "What do you think caused this dislocation?"
• "How high is the risk of recurrence after reduction?"
• "What are the side effects or precautions for the medications (analgesics and muscle relaxants)?"
• "If surgery is necessary, which surgery would you recommend, and approximately how long would the recovery period be?"
• "What restrictions should I follow in daily life, eating, and exercise?"

Examples of Tailored Questions by Disease

• "If I have recurrent dislocation, which nonsurgical treatment (splint, autologous blood injection, or botulinum toxin) is appropriate for me? What are the effects and risks of each?"
• "If I need dental treatment or surgery (tooth extraction, endoscopy, etc.), what preparations (anesthesia, protective devices, etc.) should be made to prevent recurrent dislocation?"