II. Definitions

  1. Temporomandibular Joint Dysfunction
    1. Pain and dysfunction of the Temporomandibular Joint or the Muscles of Mastication

III. Epidemiology

  1. Affects 10-15% of adults (but only 5% pursue evaluation and treatment)
  2. Most common ages: 20-40 years old (bimodal peak at 21 and 53 years old)
  3. Gender: Most common in women (3:1 ratio)

IV. Associated Conditions

  1. Comorbid pain syndromes (e.g. Fibromyalgia, chronic Headaches)
  2. Autoimmune disorders
  3. Sleep Apnea
  4. Major Depression
  5. Anxiety Disorder
  6. Posttraumatic Stress Disorder

V. Causes

  1. Malocclusion
  2. Displacement of condylar head
  3. Bruxism
  4. Trauma
  5. Acute synovitis
  6. Arthritis (Osteoarthritis or Rheumatoid Arthritis)
  7. Dental Caries or dental abscess
  8. Herpes Zoster

VI. Symptoms

  1. Pain on opening and closing mouth or chewing
    1. Consider alternative diagnosis if pain is not affected by jaw opening and closing
    2. Pain at TMJ is classically anterior to tragus
    3. Worse in the morning
  2. Pain Radiation
    1. Facial pain (96%)
    2. Ear Pain (82%)
    3. Headache (79%)
    4. Jaw pain (75%)
    5. Cheek pain
    6. Temple pain
    7. Eye Pain
    8. Neck Pain
    9. Shoulder Pain
    10. Cooper (2007) Cranio 25(2): 114-26 [PubMed]
  3. Restricted Jaw function
    1. Jaw movement feels 'Tight'
    2. Sudden 'catching' suggests mechanical dysfunction
  4. Noise, popping, clicking or crepitation at TMJ
    1. Clicking or grating sound (common and not a marker of worsening or improvement)
    2. Exacerbated by chewing
  5. Other symptoms
    1. Tinnitus, Decreased Hearing or sound hyperacuity are reported by one third of patients
    2. Temporal Headache
      1. Associated with TMJ Dysfunction
      2. May be provoked by jaw movement

VII. Signs

  1. Temporomandibular Joint exam technique
    1. Apply index finger on either side of face
      1. Position finger preauricular over pretragal area or inside external meatus
    2. Patient opens mouth widely and closes several times
  2. Observe for
    1. Clicking or popping noises or Sensation
      1. Click on opening and again on closing suggests disc displacement with reduction
      2. Crepitation suggests TMJ Osteoarthritis
    2. Limited range of opening (Normally 4-5cm, abnormal if <3 to 3.5 cm)
      1. Disc displacement may interfere with condyle translation (Closed lock)
    3. Subluxation (locking on opening)
    4. Deviation of jaw during movement (>7 mm lateral movement)
    5. Wearing down of incisal surfaces of teeth
    6. TMJ Joint Pain on palpation
      1. Suggests intra-articular disorder
    7. Temporalis Muscle, masseter Muscle or neck Muscle (e.g. sternocleidomastoid Muscle) tenderness on palpation
      1. Suggests masticatory Muscle disorder or myofacial pain

IX. Classification

  1. TMJ is considered chronic after 3 months of symptoms
  2. TMJ due to articular disorder (intra-articular causes)
    1. Articular disc displacement (most common intra-articular condition)
      1. Jaw movement triggers clicks, snaps and pops
      2. Trismus or locking Sensation
    2. Anklyosis, synovitis, fibrosis, capsulitis or Osteoarthritis of the Temporomandibular Joint
      1. Pain on TMJ palpation
      2. Crepitation on jaw movement
      3. Restricted jaw range of motion may impair speech and chewing
    3. Hypermobile jaw
      1. Joint Laxity or subluxation
    4. Condylar process Fracture
    5. Temporomandibular Joint disclocation
    6. Congenital disorder or tumor of the Mandible or cranial bones
  3. TMJ due to masticatory Muscle disorders (extra-articular causes, 50% of cases)
    1. Myofascial Pain
    2. Myofibrotic contracture
    3. Myositis, Muscle spasm or Tendinitis
    4. Neoplasm

X. Imaging

  1. Imaging Indications (and for dental or maxillofacial surgery Consultation)
    1. Unclear diagnosis
    2. Failed conservative management
    3. Facial Trauma
    4. Jaw Dislocation
    5. Malocclusion
    6. Suspected abscess
    7. Osteoarthritis suspected
    8. Palpable mass
    9. Motor or sensory deficits or other atypical findings
  2. Jaw XRay (Transcranial and transmaxillary or panorex views)
  3. Jaw CT or Maxillofacial CT
    1. Often performed in emergency settings following acute Trauma or suspected abscess
    2. Cone-beam CT is preferred if available (and focus is jaw, and not the remainder of maxillofacial bones)
      1. Less radiation exposure and better spatial resolution than conventional CT
  4. Arthroscopy
  5. Jaw MRI
    1. Preferred imaging for a comprehensive imaging evaluation of the jaw
    2. Detects soft tissue derangement (e.g. TMJ disc displacement)
    3. Indicated in cases refractory to conservative management or with suspected intraarticular cause
    4. Test Sensitivity: 78-95%
    5. Test Specificity: 66-80% (up to a 34% False Positive Rate)
    6. Lamot (2013) Oral Surg Oral Med Oral Pathol Oral Radiol 116(2): 258-63 [PubMed]
  6. Jaw Ultrasound
    1. Consider as an alternative to Jaw MRI to evaluate for disc displacement or effusion
    2. Not commonly used in practice due to the technical difficulty in imaging the joint
    3. Bas (2011) J Oral Maxillofac Surg 69(5): 1304-10 [PubMed]

XI. Differential Diagnosis

XII. Management: General Measures

  1. General measures are effective in 80% of cases
  2. No chewing gum, finger nails, ice, pencils
  3. Avoid tooth grinding and tooth clenching
  4. Avoid excessive jaw opening (e.g. Yawning or on tooth hygiene such as Tooth Brushing)
  5. Very soft diet
  6. Analgesics
    1. NSAIDs are effective for local synovitis or Myositis
      1. Use the lowest effective dose for the shortest duration needed
    2. Avoid Opioids
    3. Avoid Tramadol (ineffective)
    4. Avoid Topical Analgesics (ineffective)
  7. Local massage
  8. Heating pad or local moist heat (or ice packs if patient prefers) as needed
  9. Other measures
    1. Elevate head of bed to 30 degrees or more
    2. Optimize head Posture
    3. Optimize Sleep Hygiene

XIII. Management: Bruxism and Chronic Pain Management (masticatory Muscle or myofacial pain)

  1. Muscle relaxants (e.g. Flexeril)
    1. Haggman (2017) J Oral Rehabil 44(10): 800-26 [PubMed]
  2. Neuropathic Pain Medications
    1. Tricyclic Antidepressants at bedtime
      1. Amitriptyline or Nortriptyline 25-30 mg orally at bedtime
      2. Rizzatti-Barbosa (2003) Cranio 21(3): 221-5 [PubMed]
    2. Gabapentin
      1. Dose: Start 300 mg at bedtime and advance
      2. Kimos (2007) Pain 127(1-2):151-60 [PubMed]
  3. Cognitive Behavioral Therapy or biofeedback (insufficient evidence)
    1. Aggarwal (2011) Cochrane Database Syst Rev (11):CD008456 [PubMed]
  4. Physical therapy (weak support)
    1. McNeely (2006) Phys Ther 86(5): 710-25 [PubMed]
  5. Acupuncture
    1. Protocols of 6-8 sessions of 15-30 min each
    2. Rosted (2001) Oral Dis 7(2): 109-115 [PubMed]
    3. Cho (2010) J Orofac Pain 24(2): 152-62 [PubMed]
  6. Transcutaneous electrical nerve stimulation (TENS unit)
  7. Anxiolytics or Antidepressants
    1. Risk of Bruxism with SSRIs (rare)
    2. SSRIs and SNRIs appear ineffective for Chronic Pain of TMJ Dysfunction
    3. Benzodiazepines have been used for short 2-4 week courses (but risk of dependence)
  8. Temporomandibular Joint Injection
    1. Anesthetic injections may be used diagnostically
      1. See Temporomandibular Joint Diagnostic Injection
    2. Intraarticular Corticosteroids
      1. Unclear benefit, and typically avoided due to risk of articular cartilage damage
    3. Onabotulinumtoxin A (Botox)
      1. Variable evidence
      2. Soares (2014) Cochrane Database Syst Rev (7): CD007533 [PubMed]
    4. Other injections (e.g. hyaluronate, Platelet rich plasma) have not shown consistent benefit
      1. Golato (2016) Int J Oral Maxillofac Surg 45(12): 1531-7 [PubMed]
      2. Li (2020) J Oral Facial Pain Headache 34(2): 149-56 [PubMed]

XIV. Management: Dental Occlusion and intra-articular disorders

  1. Referral to oral and maxillofacial surgery for refractory cases
    1. Also consider referral in Trauma, neoplasm or other atypical cases (see imaging indications above)
  2. Orthodontic appliances
    1. Nonoccluding splint (simple splints)
      1. Prevent teeth clenching and Bruxism by opening the jaw
      2. Inexpensive, pre-fabricated splints are available at pharmacies
    2. Occlusal dental device or night guard (Occluding splints, stabilization splints)
      1. Custom made to assist teeth alignment
      2. Price runs several hundred dollars due to custom fit and adjustment by dentist
      3. Alleviates symptoms in over 70% of TMJ patients
  3. Surgery
    1. Indicated in less than 5% of TMJ patients
    2. Consider in cases of refractory intra-articular disorders (see above)
    3. Procedures include Arthrocentesis, Diskectomy, condyotomy, total joint replacement
    4. Surgery has a high failure rate with risk of pain and dysfunction

XV. Course: Prognosis

  1. Spontaneous resolution of symptoms (without any intervention) in 40% of patients
  2. Improvement in one year: 50%
  3. Improvement completely in 3 years: 85%

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