Temporomandibular Joint Disorders (TMD)

Temporomandibular Joint Disorders (TMD)

• Anatomy: The TMJ involves the temporal bone and mandibular condyle, with an articular disc acting as a cushion. Muscles like the temporalis, masseter, and pterygoids are crucial for jaw movement, with nerve supply from the trigeminal nerve. Surrounding structures include the ear canal and paranasal sinuses.

Clinical Features of TMD

• Pain History (SOCRATES): Pain locations include the TMJs, mastication muscles, and sometimes ears, jaw angles, or temples. Onset can be sudden or gradual. Characterized by aching, deep, continuous pain, potentially with acute flares. Pain may radiate to the ears, teeth, or temples. Rest and pain relief often alleviate symptoms. Pain can be continuous or episodic with acute flares worsened by chewing, yawning, or prolonged mouth opening. Severity varies.
• Clinical Presentation (Symptoms):
  • Myalgia: Pain in jaw muscles, worsening with movement or parafunctional habits (e.g., teeth grinding).
  • Arthralgia: TMJ-localized pain, often felt during palpation or jaw movement.
  • Intra-Articular Disorders: Clicking, popping, snapping sounds, limited or locked jaw opening, and crepitus (grinding) during movement.
  • Headaches: Commonly localized in the temples, associated with jaw movement.

Epidemiology

• TMD affects a significant portion of the population (up to 1/3).
• Prevalence varies by age group with higher prevalence in adolescents (2-6%) and adults over 45 (2-7%).
• Slight female predominance.
• Studies (e.g., OPPERA) show that TMD episodes can be single, recurrent, or persistent (12%, 65%, and 19%, respectively).

Aetiology

• Multifactorial: TMD involves complex interactions of:
  • Anatomical factors: Joint and disc dysfunction.
  • Physiological aspects: Muscle hyperactivity, sensory sensitivity.
  • Psychological factors: Stress, anxiety, depression.
  • Associated conditions: Chronic pain syndromes (e.g., fibromyalgia).

Red Flag Symptoms

• Giant Cell Arteritis: Age >50, unilateral jaw pain (claudication) during chewing, temporal artery tenderness. Potential for blindness; immediate referral and high-dose steroids are necessary.
• Trigeminal Neuralgia: Severe, episodic, unilateral pain in the trigeminal nerve area.
• Malignancy: Cancer history, facial asymmetry, lymph node swelling, difficulty opening the jaw, sensory/motor changes.
• Infections: Persistent swelling, redness, fever (e.g., infection of the jaw).

Differential Diagnosis

• Dental issues (caries, cracked teeth).
• Paranasal sinusitis.
• Salivary gland problems (e.g., duct blockage).
• Vascular conditions (e.g., giant cell arteritis, migraine).
• Neuropathic conditions (e.g., trigeminal neuralgia).
• Referenced pain from ear infections or sinus problems.
• Cancers affecting the head, neck, or skull base.

Diagnostic Pathway

• History and Examination: Examining TMJs for tenderness or noise production. Assessing jaw movement for limitations. Evaluating mastication muscles for tenderness or hypertrophy.
• Red Flag Exclusion: Ruling out any potentially serious medical conditions.
• Diagnostics: Imaging (MRI or CT) only when indicated based on history and examination.

Management of TMD

• First-Line (Conservative): Patient education, self-management techniques (avoid parafunctional habits, soft diet, warm/cold compresses, exercises), relaxation techniques.
• Pharmacological: Paracetamol, NSAIDs for acute pain. Short-term benzodiazepines in severe cases. Tricyclic antidepressants for chronic pain.
• Supportive Therapies: Physical therapy to improve joint and muscle function. Acupuncture for pain relief. Cognitive behavioral therapy (CBT) to address psychological aspects. Occlusal splints (night guards).
• Avoid Irreversible Treatments: Treatments like surgery, occlusal adjustments, prothodontics, and orthodontics, except in specific, severe cases.

Referral Pathway

• Primarily primary care for conservative management.
• Specialist referral: Persistent problems, red-flag symptoms, or complicated cases to oral & maxillofacial surgeons, oral medicine specialists, or orthodontists.

Key Takeaways

• TMD is a common, treatable condition often manageable conservatively.
• Proper diagnosis involves thorough history, physical examination, and appropriate investigations.
• Management focuses on patient education and implementing reversible, conservative treatment.