Myofacial Pain Dysfunction Syndrome (MPDS) / TMJ Pain Dysfunction Syndrome

As described in Anil Ghom's Textbook of Oral Medicine (3rd Edition)

Synonyms / Terminology

• Costen's syndrome (historical - James Costen, 1934)
• TMJ pain dysfunction syndrome (Schwartz, 1956)
• Myofacial pain dysfunction syndrome (MPDS) - the currently preferred term
• Also called: craniomandibular dysfunction, TMD (temporomandibular dysfunction)

Definition

Etiology (According to Anil Ghom)

1. Abnormal Occlusion

2. Tooth-Muscle Theory

3. Prosthetics Problems

• Interceptive contacts due to faulty complete/partial dentures
• Over-closure
• Bilateral loss of molar teeth
• Increased/decreased vertical dimension in dentures
• These cause a change in the myotactic stretch reflex, supporting the view that TMJ dysfunction can result from over-closure

4. Orthodontic Problems

5. Emotional / Psychosocial Problems

• Patterns of over-behavior relating to care of teeth and food habits may lead to TMD
• Oral habits (bruxism, clenching) can cause structural damage or persistent pain
• Dysfunction of the autonomic nervous system resulting from anxiety eventually produces structural changes in end organs

6. Psychophysiologic Theory

• Degenerative arthritis (from continued jaw function in myospasm)
• Internal derangements

Pathogenesis / Cycle of Pain

Micro/macro traumatic events or continued muscle contractions → Overactivity of muscles → Muscle fatigue + decreased ATP → Anaerobic muscle environment → Accumulation of noxious metabolic end products (e.g., lactic acid) → Activation of muscle nociceptors → Muscle tone becomes spastic and sore → Muscle tenderness and pain

Clinical Features

Pain

• Sites: jaw, facial muscles, temple, frontal, occipital, preauricular region, ear (otalgia), neck
• Nature: steady dull ache; can range from acute to chronic; duration from hours to days
• Unilateral in most cases (key diagnostic feature)
• Commonly worse on awakening (due to nocturnal bruxism/clenching)

Muscle Tenderness

• Trigger points (TrPs) in muscles of mastication - most commonly in the temporalis, masseter, and pterygoid muscles
• Palpation reproduces/refers pain to distant sites

Restricted/Altered Mandibular Movement

• Limitation of mouth opening (restricted inter-incisal opening)
• Deviation or deflection of mandible on opening (towards the affected side)

Joint Sounds

• Clicking, popping, snapping sounds on mandibular movement
• Rubbing and grinding noises

Referred Symptoms (Ear and Surrounding Structures)

• Tinnitus
• Otalgia (ear pain)
• Toothache
• Partial or total hearing loss
• Deflection of the jaw

Laskin's Diagnostic Criteria for MPDS

• No clinical, radiographic, or biochemical evidence of organic changes in the TMJ
• No tenderness on palpation via the external auditory meatus

Investigations

• Radiographs: Transcranial and transorbital views of TMJ - to rule out organic bony changes (in MPDS, radiographs are typically normal)
• MRI: To assess disc position and soft tissue components
• Electromyography (EMG): Shows increased muscle activity
• Arthroscopy: Diagnostic in refractory cases

Treatment / Management

Conservative (Non-Surgical) - First Line

1. Reassurance and Patient Education

2. Rest and Restricted Jaw Function

• Soft diet
• Avoiding wide mouth opening
• Supported yawning

3. Pharmacological Treatment

• Analgesics/NSAIDs - for pain relief
• Muscle relaxants - to reduce masticatory muscle spasm (Schwartz's recommendation)
• Anxiolytics/Antidepressants - Tricyclic antidepressants (e.g., nortriptyline at night) for chronic/diffuse pain and underlying anxiety
• Benzodiazepines - short-term for acute muscle spasm

4. Occlusal Splint Therapy

• Bite splint/Night guard appliance - plastic appliance provided by the dentist; reduces nocturnal bruxism and redistributes occlusal forces
• Particularly indicated in patients with parafunctional habits (bruxism, clenching)

5. Physical Therapy

• Heat application (moist heat to masticatory muscles)
• Transcutaneous Electrical Nerve Stimulation (TENS)
• Ultrasound therapy
• Jaw exercises and stretching

6. Psychological/Behavioral Therapy

• Biofeedback
• Cognitive behavioral therapy (CBT)
• Stress management

Dental/Occlusal Management

7. Prosthodontic Therapy

8. Orthodontic Therapy

• Indicated in cross bite and traumatic bite
• Night guard appliance for patients with bruxism

9. Orthognathic Therapy

Surgical Treatment (Reserved for Refractory Cases)

• Arthrocentesis - lavage of the upper joint compartment
• Arthroscopy - diagnostic and therapeutic
• Open joint surgery (arthroplasty) - for structural pathology

Points to Remember (Anil Ghom - Summary Box)

• Patient complains of noise on rubbing, grinding, clicking, popping, snapping sounds on mandibular movement
• Tinnitus or otalgia or toothache may be present
• Partial or total hearing loss
• Deflection of jaw
• MPDS can occur due to: abnormal occlusion, emotional problems, tooth loss - all of the above
• The condition is NOT associated with radiographic evidence of organic joint changes (this distinguishes it from true TMJ arthritis)

Classification Within TMJ Disorders (Ghom's Chapter 22 Framework)

• Synovial chondromatosis
• Drug-induced disorders (steroids)

• Inflammatory disorders (Rheumatoid Arthritis, Psoriatic Arthritis, Infective Arthritis, Ankylosing Spondylitis)
• Traumatic disorders (Condylar fracture, Ankylosis, Dislocation, Subluxation, Internal derangement/disc displacement)
• Metabolic disorders (Gout)
• Neoplastic disorders (Benign and Malignant tumors)

• Textbook of Oral Medicine, Anil Ghom & Savita Ghom, 3rd Edition (Jaypee, 2014), Chapter 22: Temporomandibular Joint Disorders - accessed via dokumen.pub
• Scott-Brown's Otorhinolaryngology Head & Neck Surgery - TMD section (library)
• Supporting reference: Open Access Oral & Maxillofacial Surgery - MPDS Overview