Temporomandibular disorder (TMD)

Definition
Temporomandibular disorder refers to a group of conditions affecting the temporomandibular joint (TMJ), the masticatory muscles, and associated structures, leading to pain, limited jaw movement, and joint noises.

---

Causes

• Jaw injury or trauma

• Bruxism (teeth grinding or clenching)

• Arthritis affecting the TMJ (osteoarthritis, rheumatoid arthritis)

• Malocclusion (misalignment of teeth/jaw)

• Stress and muscle tension

• Excessive gum chewing or biting on hard objects

---

Risk Factors

• Female gender (especially 20–40 years old)

• Chronic stress

• Pre-existing arthritis

• Occupations or habits involving repetitive jaw movements

---

Pathophysiology

• Overuse or trauma leads to inflammation and dysfunction of the TMJ and associated muscles

• Displacement of the articular disc within the joint can cause clicking and locking

• Chronic muscle tension contributes to pain and restricted movement

---

Clinical Features

• Jaw pain or tenderness, especially near the ear

• Clicking, popping, or grating sounds when opening/closing the mouth

• Limited ability to open the mouth fully (trismus)

• Facial pain or headache

• Pain when chewing or talking

• Earache without infection

---

Diagnosis

• Clinical history and physical examination

• Palpation of TMJ and masticatory muscles

• Imaging (X-ray, MRI, or CT) for structural assessment in severe or persistent cases

---

Treatment

Self-care and Lifestyle Measures

• Soft diet to reduce jaw strain

• Avoid chewing gum and hard foods

• Apply warm compresses to relax muscles

• Gentle jaw stretching and relaxation exercises

• Stress management techniques

Medications

• NSAIDs for pain and inflammation

• Muscle relaxants for short-term use in muscle spasm

• Low-dose tricyclic antidepressants (e.g., amitriptyline) for chronic pain management

Doses (examples for adults)

• Ibuprofen: 400–600 mg orally every 8 hours as needed (max 2.4 g/day)

• Naproxen: 250–500 mg orally twice daily

• Amitriptyline: 10–25 mg orally at night (for chronic pain, under medical supervision)

Adjunctive Therapies

• Occlusal splints (night guards) to prevent bruxism-related damage

• Physiotherapy for jaw muscle strengthening and mobility

• Cognitive behavioural therapy (CBT) for stress-related bruxism

• Botox injections in refractory muscle spasm cases

Surgical Options

• Arthrocentesis (joint flushing)

• Arthroscopy or open joint surgery for severe structural damage

---

Complications

• Chronic facial pain

• Persistent jaw dysfunction

• Secondary headaches or ear pain

---

Quick-Reference Clinical Chart — Temporomandibular Disorder (TMD)

Feature	Details
Definition	Pain and dysfunction of the TMJ and masticatory muscles
Causes	Bruxism, arthritis, injury, malocclusion, stress
Symptoms	Jaw pain, clicking/popping, restricted mouth opening, earache, headache
Risk factors	Female, 20–40 years, stress, arthritis
Diagnosis	Clinical exam, imaging (X-ray/MRI) if severe
First-line treatment	Soft diet, warm compress, NSAIDs, stress management
Drug therapy (adult dose)	Ibuprofen 400–600 mg PO q8h PRN; Naproxen 250–500 mg PO BID; Amitriptyline 10–25 mg nocte for chronic pain
Adjunctive options	Occlusal splint, physiotherapy, CBT, Botox
Surgery	Arthrocentesis, arthroscopy, open joint surgery for severe cases
Prognosis	Most improve with conservative measures; surgery rarely required