Temporomandibular Pain Syndrome

Temporomandibular pain syndrome is a group of musculoskeletal conditions affecting the masticatory muscles, the temporomandibular joint (TMJ) and associated structures. It is the commonest cause of chronic orofacial pain of non-dental origin.

• Peak age is 20 to 50 years, with women affected 2 to 4 times more than men, and women seeking treatment more often. About 5 to 12% of the adult population has symptoms, and many more have clicking without pain.
• Subtypes:
  • Myofascial pain (masticatory muscle pain) is the commonest, at about 45% of cases.
  • Internal derangement: displacement of the articular disc, with or without reduction (clicking, locking).
  • Degenerative joint disease: osteoarthritis of the joint.
  • Inflammatory arthritis: rheumatoid arthritis, juvenile idiopathic arthritis, psoriatic arthritis, gout.
  • Hypermobility and subluxation, or dislocation.
  • Ankylosis, fibrous or bony, from trauma or infection.
• Risk factors and contributors: bruxism (awake and sleep), jaw clenching, trauma (whiplash, a blow to the jaw, prolonged dental work or intubation), malocclusion (a weak association), joint hypermobility, psychosocial stress, anxiety, depression, poor sleep, other chronic pain conditions (fibromyalgia, irritable bowel syndrome, migraine) and gum chewing.
• The cause is multifactorial. A biopsychosocial model fits best, with local joint and muscle factors, central pain sensitisation and psychological factors.
• Most cases are self-limiting or settle with conservative care. About 10 to 15% develop chronic pain.

• Dull, aching pain in the pre-auricular area, jaw, cheek and temple, worse on chewing, yawning, speaking and at the end of the day, and often worse in the morning (bruxism). Pain may spread to the ear, teeth, neck and head.
• Clicking, popping or grating (crepitus) of the joint on opening and closing, a sensation of the jaw catching or locking (closed lock: limited opening below 35 to 40 mm), and deviation of the jaw to the affected side on opening. Normal maximum opening is 40 to 55 mm, or three finger widths.
• Associated symptoms: tension type headache, earache or fullness without ear disease, tinnitus, dizziness, neck and shoulder pain, tooth sensitivity, and facial fatigue after meals.
• Tenderness of the masseter, temporalis, medial pterygoid and lateral pterygoid muscles, and over the joint. Worn teeth, scalloped tongue edges and cheek ridging suggest bruxism.
• Differential diagnosis: dental disease (caries, pulpitis, abscess, cracked tooth), sinusitis, otitis media or externa, parotitis, salivary gland stones, trigeminal neuralgia, giant cell (temporal) arteritis, migraine, tension type headache, cluster headache, neck disease, ear and throat cancers, myocardial ischaemia (jaw pain on exertion), glossopharyngeal neuralgia, post-herpetic neuralgia, and eagle syndrome (elongated styloid process).
• Red flags: jaw claudication, headache, scalp tenderness, visual symptoms and age over 50 (giant cell arteritis); progressive trismus, fever, swelling or a mass (infection or tumour); jaw pain on exertion with sweating or chest symptoms (cardiac); facial numbness, weight loss or a neck mass; trauma with malocclusion or inability to close the mouth (fracture or dislocation); and a persistently locked jaw.
• Complications: chronic pain, limited diet, sleep disturbance, depression, tooth wear, joint degeneration, chronic dislocation and ankylosis.

• Clinical diagnosis from history and examination. Record the maximum comfortable and maximum assisted mouth opening in millimetres, lateral movements (normal 8 to 10 mm), the path of opening (deviation or deflection), joint sounds, and tenderness of the muscles and the joints with firm palpation (about 1 kg of pressure for muscles, 0.5 kg for joints).
• Examine the teeth, occlusion and bite wear, the cervical spine, the ears and the cranial nerves. Check the temporal arteries in older patients.
• Imaging is not needed for most patients. Indications are trauma, locked joint not responding to treatment, suspected inflammatory or degenerative disease, suspected tumour, failure of conservative treatment, or before surgery.
  • Panoramic radiograph: screening for bone and tooth disease.
  • Cone beam CT or CT: bony changes, osteophytes, erosions, condylar position.
  • MRI: disc position and joint effusion (the best test for internal derangement) and bone marrow oedema.
  • Ultrasound can detect effusion and disc displacement in specialist hands.
• Laboratory tests are needed when inflammatory disease or giant cell arteritis is suspected: erythrocyte sedimentation rate, C-reactive protein, full blood count, rheumatoid factor, anti-cyclic citrullinated peptide antibody and uric acid. In suspected giant cell arteritis, start prednisolone 40 to 60 mg daily immediately and arrange temporal artery biopsy or ultrasound without delay.
• Dental referral for assessment of occlusion, tooth wear and dental pain.
• Screen for depression, anxiety and sleep disorders, because they predict chronic pain.

• Reassurance and self-care (first line, effective in about 70 to 80% of patients):
  • Explain the benign nature of the condition and its tendency to settle.
  • Soft diet for 2 to 4 weeks, with small bites, avoiding hard, chewy foods, gum and wide yawning (limit opening to about 2 fingers in width).
  • Moist heat to the jaw muscles for 15 to 20 minutes 3 times daily, or ice for acute pain, and gentle self-massage of the masseter and temporalis.
  • Jaw exercises: relaxed jaw position (tongue on the roof of the mouth, teeth apart, lips together), controlled opening against a mirror, passive stretching with 2 or 3 stacked fingers or a stack of tongue depressors 3 to 5 times daily, and resisted opening and closing exercises.
  • Reduce clenching and grinding habits (awareness, habit reversal), good sleep hygiene, and relaxation or cognitive behavioural therapy for stress, which gives lasting benefit.
  • Avoid sleeping on the stomach or resting the jaw on the hand.
• Analgesia:
  • Ibuprofen 400 mg orally 8 hourly with food for 2 weeks, or naproxen 500 mg orally 12 hourly with food for 2 weeks, with a proton pump inhibitor in at risk patients. Review at 2 weeks.
  • Paracetamol 1 g orally 6 hourly (maximum 4 g per day) when NSAIDs are unsuitable.
  • Topical diclofenac 1% gel 2 to 4 g over the muscle or joint 3 to 4 times daily.
  • Avoid opioids, which are not effective for long term pain and worsen outcomes.
• Muscle relaxants for acute muscle spasm, short course only: diazepam 2 mg orally at night for 1 to 2 weeks (avoid in elderly people, those with sleep apnoea, and with alcohol or opioids), or cyclobenzaprine 5 to 10 mg orally at night where available.
• Chronic pain and neuropathic or sleep related features: amitriptyline 10 mg orally at night, increased by 10 mg every 1 to 2 weeks to 25 to 50 mg (maximum 75 mg in this indication), for 3 to 6 months, or nortriptyline 10 to 25 mg at night. Gabapentin 100 mg at night, increased to 300 mg 3 times daily over 2 to 3 weeks, or duloxetine 30 to 60 mg daily, may be used for refractory pain. Review at 6 to 8 weeks.
• Occlusal splint (stabilisation appliance): a hard acrylic, custom made splint worn at night for 3 to 6 months for bruxism and myofascial pain. It reduces muscle load, and evidence of benefit is modest. Avoid permanent changes to the bite (irreversible occlusal adjustment, extensive restorations) for TMD alone.
• Physiotherapy: manual therapy, postural correction, cervical spine treatment, ultrasound, laser therapy and transcutaneous electrical nerve stimulation have a modest and short term effect.
• Botulinum toxin type A injection into the masseter (25 to 50 units per side) and temporalis (10 to 25 units per side) every 3 to 6 months for refractory myofascial pain or bruxism, in specialist care. Weakness of chewing and a change in contour are expected effects.
• Joint procedures (specialist):
  • Arthrocentesis (joint lavage) with 100 to 300 mL of sterile saline, with or without hyaluronic acid or corticosteroid, for acute closed lock and persistent joint pain. Success rates are 70 to 90%.
  • Intra articular corticosteroid (triamcinolone 20 mg or methylprednisolone 20 to 40 mg), limited to 1 to 2 injections to avoid damage to the cartilage and bone.
  • Arthroscopy, disc repositioning or repair, and joint replacement for severe structural disease that fails less invasive treatment.
• Acute closed lock (disc displacement without reduction): manual reduction technique by a trained clinician, with analgesia and muscle relaxation, then a soft diet and exercises. Persistent lock needs arthrocentesis.
• Acute dislocation (open lock): reduce with the thumbs on the lower molars (padded with gauze), pressing down and backwards, under analgesia or sedation. Give diazepam 5 mg orally or midazolam 1 to 2 mg IV if needed, and advise avoiding wide opening (bandage the jaw for 1 to 2 weeks). Chronic recurrent dislocation needs specialist care (injection of autologous blood or dextrose into the joint, or eminectomy).
• Inflammatory arthritis: refer to rheumatology for disease modifying treatment.
• Special groups:
  • Pregnancy: use paracetamol, heat, exercises and a soft diet. Avoid NSAIDs from 20 weeks of gestation and avoid tricyclic antidepressants unless necessary.
  • Children and adolescents: give reassurance, exercises, and a splint only when symptoms are severe. Examine for juvenile idiopathic arthritis, and for growth disturbance with limited opening.
  • Elderly: consider giant cell arteritis, osteoarthritis, and dental problems. Use paracetamol and topical agents, and avoid sedatives.
  • Renal impairment and peptic ulcer disease: avoid NSAIDs.
  • Depression or anxiety: treat in parallel, because they prolong pain.
• Follow up: review at 2 to 4 weeks, and at 3 months. Refer to oral and maxillofacial surgery, a TMD specialist or pain medicine for pain beyond 3 months, locking, severe limitation, or suspected arthritis, tumour or infection. Refer urgently for suspected giant cell arteritis.