TMJ Disorders Overview Quiz

TMJ Disorders

• TMJ disorders involve the temporomandibular joint, a complex joint connecting the jaw to the skull.
• Classified as intracapsular and extracapsular disorders.

Intracapsular Disorders

• Congenital:
  • Agenesis (absence of one or both condyles).
  • Double condyle.
  • Hyperplasia (overgrowth of the condyle).
  • Hypoplasia (underdevelopment of the condyle).
• Infections:
  • Osteomyelitis (bone infection).
  • Septic arthritis (infection of the joint).
  • Rheumatoid arthritis (inflammatory disease that affects joints, including the TMJ).
• Degenerative:
  • Osteoarthritis (degenerative joint disease).
  • Trauma (to the meniscus or fractured condylar head).
• Functional:
  • Subluxation (partial dislocation).
  • Dislocation.
  • Internal disc derangement.
• Neoplastic:
  • Osteoma.
  • Osteochondroma.

Extracapsular Disorders

• MPDS (Myofascial Pain Dysfunction Syndrome):
  • Muscle spasms supporting the jaw due to overclosure or overextension.
• Iatrogenic factors: Associated with prolonged dental procedures.
• Infections: Osteomyelitis, periostitis.
• Neoplasia: Tumors of the condyle and ramus.

Rheumatological Considerations

• Rheumatoid arthritis (RA) is an inflammatory disease primarily affecting periarticular tissues and secondarily the bone. It begins with synovial membrane vasculitis, round cell infiltration, and subsequent granulation tissue formation.
• This cellular infiltration causes bone erosion and flattening of the convex condylar surface.

Signs and Symptoms

• Unilateral or bilateral pain.
• Decreased mandibular movements.
• Difficulty in chewing.
• Deviation of the mandible towards the affected side.
• Muscle pain.
• Occasional swelling and redness over the joint area.
• Morning stiffness, symptoms relieved by activity.
• Changes in interproximal phalanges.

Diagnosis

• Morning stiffness greater than 1 hour.
• Arthritis affecting three or more joints.
• Arthritis of interphalangeal joints.
• Symmetric arthritis.
• Presence of specific antibodies, like Anti-cyclic citrullinated proteins (anti-CCP) in serum, although not always present.

Imaging

• CT scan of erosion of condyle.
• Coronal section showing flattening of articular surface.
• Osteophyte formation seen as radiopaque projection on CT scan.
• T2-weighted MRI showing joint effusion.
• Coronal CBCT image showing Ely's cyst.

Treatment

• Initial therapy is often methotrexate, which reduces disease activity, joint erosions and provides long-term mortality reduction.
• Prednisolone, and azathioprine can also be used.
• Aspirin was once used but can cause defective platelet aggregation.
• Rest to the joint, soft diet, and occlusal appliances may be helpful.
• Ibuprofen 400mg TDS for 5-10 days.
• Aspiration of fluid, intraarticular steroid injections, exercise to improve mandibular movement.
• Surgical options for severe functional impairment or intractable pain.

Degenerative Joint Disease (DJD)

• Primarily affects articular cartilage and subchondral bone.
• Secondary synovitis (inflammation of the synovial membrane).
• Localized disease without systemic symptoms.
• Initiates with articular cartilage thinning and clefts (fibrillation), progressing towards cartilage breakdown, underlying bone sclerosis, subchondylar cysts, and osteophyte development.

Clinical Features (DJD)

• Unilateral pain directly over the condyle.
• Limitation of mandibular opening.
• Crepitus (grating or crackling sound).
• Stiffness after periods of inactivity.
• Joint tenderness and crepitus upon palpation through the external auditory meatus.
• Deviation of the mandible to the affected side on opening.

Articular Disc Displacement (ADD)

• Abnormal relationship between the articular disc, the mandibular condyle, and the articular eminence.
• Due to stretching or tearing of restraining ligaments.
• Possible result in abnormal joint sounds, decreased range of mandibular motion, and pain during mandibular movement.
• Displaced disc becomes anterior to the mandibular condyle.

Types of ADD

• Anterior disk displacement with reduction (clicking joint).
• Anterior disk displacement with intermittent locking.
• Anterior disk displacement without reduction (closed lock).

Etiology (ADD)

• Direct trauma to the joint from blow to the mandible.
• Chronic low-grade microtrauma from bruxism or teeth clenching.
• Generalized joint laxity(excessive looseness).
• Combination of factors related to join anatomy, facial skeleton, connective tissue chemistry, and chronic loading increases the susceptibility to disc disturbance and ligament displacement.

Clinical Features (ADD)

• Pain directly over the joint during mandibular opening, especially at maximum.
• Limited lateral movement to the side away from the displacement.
• Deviation of mandible towards the affected side during maximal opening.
• Decreased translation of the condyle on the side of the displacement.

Posterior Disc Displacement

• When a part of the disc positioned posterior to the top of the condyle.
• Clinical feature: often unable to bite on both sides unilaterally, and or bilaterally.

Clinical Features (Posterior Disc Displacement)

• Sudden inability to close mouth and or bite together.
• Pain in affected joint when trying to bring teeth together.
• Forward displacement of mandible to the affected side.
• Limited lateral movement on the affected side.
• No restriction in mouth opening.

Management (ADD)

• Conservative treatment: NSAIDs, heat, soft diet, rest, and occlusal splints..
• Intraarticular steroid injections.
• Anti-inflammatory effects of doxycycline therapy reduces symptoms.
• In severe cases, arthroplasty (removal of osteophytes and erosive areas).

Ankylosis

• Greek for 'stiff joint'.
• Hypomobility or immobility of the joint lead to partial or full mouth opening dysfunction.
• Classified as false or true, extra- or intra-articular, fibrous or bony, unilateral or bilateral, and partial or complete.

Etiology (Ankylosis)

• Trauma (congenital traumas, birth injuries with forceps delivery, hemarthrosis, condylar fracture)..
• Infections (otitis media, parotitis, tonsillitis, furuncle, abscesses around joint, osteomyelitis, actinomycosis).
• Inflammation (rheumatoid arthritis, osteoarthritis, septic arthritis).
• Systemic diseases (smallpox, scarlet fever, typhoid, gonoccocal infections, scleroderma).
• Other factors (bifid condyle, prolonged trismus, prolonged immobilization, burns).

Clinical Features (Unilateral Ankylosis)

• Obvious facial asymmetry..
• Deviation of mandible and chin to the affected side.
• Recession of chin and hypoplastic mandible on affected side, with teeth in the ramus.
• Flattening and elongation of unaffected side of the face; roundness and fullness of the face on the affected side.
• Prominent antegonial notch on the affected side.
• Limited or absent mouth opening.
• Unilateral posterior crossbite on ipsilateral side.

Clinical Features (Bilateral Ankylosis)

• Inability to open the mouth (severe reduction in oral opening).
• Bilateral symmetrical mandible, but micrognathia (“bird face”).
• Well-defined bilateral antegonial notch.
• Class II malocclusion.
• Multiple carious teeth with poor oral hygiene.
• Teeth crowding.
• Multiple impacted teeth (appearing within the ramus)..
• (Note possible image of bilateral ankylosis showing "bird face" appearance).

Treatment (Ankylosis)

• Treatment is always surgical. Common methods include:
  • Condylectomy.
  • Gap arthroplasty.
  • Interpositional arthroplasty.

Hypermobility, Subluxation, and Dislocation

• Normal condylar head translation to a position under articular eminence.
• Dislocation: Condylar head excursion beyond the limit. The condyle remains anterior and superior to articular eminence. Closing muscles spasm.
• Subluxation: Repeated dislocation episodes; condylar excursion beyond the articular eminence with return to normal position during manipulation.
  Characteristics of habitual subluxation include incomplete self-reduction.

Subluxation Etiology

• Ligamentous and capsular flaccidity.
• Erosion of articular eminence.
• Flattening and trauma to the TMJ.
• Predicators include: yawning, laughing, severe epilepsy, and Ehlers-Danlos syndrome.

Subluxation Clinical Features

• Mouth remains open due to associated lateral pterygoid muscle spasm.
• Difficulty with mastication and speech.
• Deviation of chin to the contralateral side.
• Inability to palpate the affected condyle.
• Unilateral lateral crossbite and open bite on the contralateral side.
• Bilateral open bite in bilateral subluxation.
• Bilateral or unilateral depression visible in front of the tragus (pre-tragal notch) .

Subluxation Treatment

• Intermaxillary fixation or limiting oral opening with elastics.
• Use of sclerosing agents.
• Surgical procedures (capsule tightening if severe).

Dislocation/Subluxation Differences

• Subluxation: self-correctable by the patient. Posterior articular slope is flat.
• Dislocation: requires medical intervention for correction; Posterior articular slope is steep.

Myofascial Pain Dysfunction Syndrome (MPDS)

• A disease entity, also known as Costen's syndrome, characterized by muscle spasm in the jaw muscles.
• Multiple potential causes including, but not limited to, overclosure or overextension of the muscles.

MPDS Pathogenesis

• Tension, oral habits, and dental irritants.
• Muscle fatigue, overextension, overcontraction.
• Overclosure due to decreased VD.
• MPDS occlusal disharmony and altered chewing function.
• Degenerative arthritis.
• Dental restorations such as full dentures (FPD) or removable partial dentures (RPD) with high points.

MPDS Treatment Considerations

• Multiple therapeutic approaches are recommended, starting with patient education and counseling.
• Pharmacotherapy: NSAIDs, diclofenac gel, pain relievers, hot fomentation, and muscle relaxants/tricyclic antidepressants to reduce anxiety.
• Other therapy approaches include intraoral appliance therapy, trigger point therapy, relaxation therapy, and physiotherapy.

Test your knowledge on TMJ disorders with this informative quiz. Explore the types of TMJ disorders, their treatments, and therapeutic approaches. This quiz will challenge your understanding of both intracapsular and extracapsular issues related to the temporomandibular joint.