TMJ arthritis Flashcards
Does the condyle articulate directly with the glenoid fossa?
Glenoid fossa at base of temporal bone
No contact between the condyle and the post glenoid surface even during retrusion
Articular disc forms cap around the head of the condyle
How are the mandibular condyles shaped?
Mandibular condyles are olive shaped and the axis is not straight lined. Lateral pole is anteriorly placed and medial pole is posteriorly placed.
What is the articular disc of the TMJ?
Articular disc is a biconcave fibrous structure that divides upper and lower compartment of the TMJ. It fits around the condyle like a cap and in front of the condyle. Between the 2 bands is an avascular thin area.
Disc is attached to the neck of the condyle on the posterior condyle and elastic tissue fuses with the squamotympanic fissure
Anteriorly some fibers fuse with the capsule and some fibers superior head of the lateral pterygoid muscle.
What movements do the different compartments allow?
Superior compartments allows translatory movements
Inferior compartment allows hinge movements
What are the attachments of the joint capsule of the TMJ?
Medial and lateral poles of the condyle beneath the articular disc as well as laterally along the roots of the zygomatic process and medially along the medial aspect of the glenoid process
What ligaments improve TMJ stability?
Strengthened laterally by a band of fibrous tissue called the lateral ligament preventing lateral dislocation of the joint.
Sphenomandibular ligament and stylomandibular ligament help to stabilize the TMJ
What are the roles of the synovial membrane?
Lubrication
Nutrition
Removal of wastes
protection
What is arthritis?
Inflammation of the articular surfaces of the joint
How common is arthritis in Australia?
> 3.1 million people self-report arthritis
1.6 million affected by osteoarthritis
> 428000 suffer from Rheumatoid arthritis
How does age affect arthritis?
Prevalence of arthritis increases with age most common in people over 45 years of age. Higher in females of older age groups
What are the types of arthritisi that can affect the TMJ?
Degenerative
Traumatic
Infectious
Metabolic
Immune-mediated
What is osteoarthritis?
Inflammatory condition affecting the articular cartilage of synovial joints.
Affected by mechanical loading, physical stress and traumatic injury of the joints
How does osteoarthritis affect the TMJ?
Most common disease affecting the TMJ
May be present in TMJ in absence of other joints
What are the subtypes of osteoarthritis?
Primary of unknown aetiology
Secondary due to macrotrauma or chronic microtrauma
What is osteoarthrosis?
Non-inflammatory condition that produces similar degenerative changes to O. However, this is now a redundant term and is just called osteoarthritis.
What are the symptoms of osteoarthritis of the TMJ?
Pain during chewing and worse in late afternoon or evening.
Masticatory muscles are hyperactive to protect the TMJ
Masticatory muscle fatigue.
Limited mouth opening and decreased range of motion
Crepitation
Other symptoms of referred pain like headaches.
What radiographic imaging should be used for TMJ arthritis?
No general consensus as to which imaging modality should be gold standard.
OPG is often not enough for diagnosis of TMJ arthritis
What is the radiolucency seen in the head of the condyle on CT in arthritis?
Subchondral cyst formation which is a difference in attentuation of the beam in that area not a true cyst
What are the radiological findings of arthritis on CT?
Birds beak appearance of glenoid fossa due to osteophyte appearance
Subchondral cyst
Reduction in joint space
Irregularities of the bone
What is used for diagnosis of osteoarthritis?
Clinical findings + Radiographic features
What are the DDx for OA?
Rheumatoid arthritis
Myofascial pain
Internal derangement
What is the prognosis for OA?
Symptoms most severe for the first 4 - 7 months. Worst at 8 - 9 months and least painful at 10 -12 months
How is TMJ OA managed?
Treat symptomatic OA not radiographic changes
Supportive therapy (education and reassurance, habit reduction, etc)
Medications (Analgesics and NSAIDs)
Intra-articular treatments
Surgery (arthroseptesis, arthroplasty)
Dental treatment indicated if bite has changed.
What is traumatic arthritis?
Secondary to sudden acute macrotrauma
Depends on severity of trauma to the joint. If severe enough can cause haemarthrosis and damage to the synovial membrane with inflammatory response leading to fibrosis contractions and adhesions in the joint space with fibrous ankylosis). Minor trauma can cause dislocation of the disc.
In severe cases can cause degenerative joint disease and joint asymmetry.
What are the clinical symptoms of traumatic arthritis?
Severe pain at rest and with movement
Joint tender to palpation, occassionally swollen
Decreased ROM
Posterior open bite on affected side
What are the clinical and radiographic findings of traumatic arthritis?
Severe pain at rest and with movement
Joint tender to palpation occassionally swollen
Decreased ROM
Posterior open bite on affected side
Radiograph shows oedema and swelling of intracapsular and capsular structures, and late changes such as a degenerative joint disease or bony ankylosis
How is traumatic arthritis managed?
Rule out mandibular fractures
Supoprtive therapy such as education and reassurance, jaw rest, habit reduction, physical therapy, and exercises at home may be useful. Stabilisation appliance is given occassionally.
Analgesia and NSAIDs
What is Rheumatoid arthritis?
Chronic, systemic, slowly progressive inflammatory disease
Predominantly affects the peri-articular tissue such as the synovial membrane
Progressive destruction of articular and periarticular soft tissue.
Extra articular manifestations can form.
Bones and cartilage can slowly erode.
What are the stages of RA?
Stage 1: Synovitis where synovial membrane is thickened and bones + cartilage erode
Stage 2: Pannus formation with extensive cartilage loss and exposed and pitted boney surfaes
Stage 3: Fibrous ankylosis
Stage 4 is bony ankylosis
What causes RA?
Unknown aetiology
Seen in 2.5% of population
F>M
Peak onset at 40 - 60 years of age
How common is TMJ involvement in RA patients?
50 - 70% of patients with RA have TMJ involvement
What are the clinical symptoms ofTMJ RA?
Deep, dull aching pain in preauricular area espeially during chewing
Profile alterations
Limited range of motion
Morning stiffness (can be present)
Crepitus
Otalgia
What labwork can allow diagnosis of RA?
FBC, RF, ANA, anti-CCP, ESR, and CRP
What are the differential diagnoses for RA?
OA
Psoriatic arthritis
Ankylosing spondylitis
Gout
How can RA be seen radiographically?
Joint space loss
Condylar flattening
Synovial proliferation and condylar destruction
How is RA managed?
Medication:
Noncurative but reduce until remission:
NSAIDs
Disease modifying Anti-Rheumatoid Drugs / biologics
Corticosteroids
Dental:
Supportive therapy, monitor for occlusal changes clinically
Other:
Psych support
Surgery
Imaging
What is juvenile idiopathic arthritis?
Clinically heterogeneous inflammatory joint disease of unknown aetiology in children especially female children. Onset is after 16 years of age.
Can be a systemic, polyarticular or oligoarticular disease
How commonly is the TMJ involved in JIA?
80% of cases but asymptomatic in 70% of these cases
What are the clinical manifestations of JIA?
Pain and TMJ tenderness
Stiffness
Decreased ROM
Joint crepitation
Otalgia
Late manifestations
Micrognathia
What imaging modality is commonly used for JIA?
MRI as children would be sensitive to too much radiation from a CT
Better soft tissue resolution in MRI.
What are the radiographic features of JIA?
Pannus formation
No bony change
Thinning of the articular disc
Condylar and articular eminence flattening
Diffuse articular surface flattening
What are the goals of JIA management?
Early recognition
Prevention of damage
Suppressing disease
How is JIA managed?
NSAIDs
DMARDs/Biologics
Corticosteroids
SAME AS RA
Dental management:
Supportive therapy
Monitor for occlusal changes
Stabilisation splint is usually utilized.
Other:
Imaging
Psychological support
Surgery
What is psoriasis? How often does psoriasis affect joints?
Psoriasis is a chronic inflammatory dermatologic disease
Joints are affected in up to 30% of patients. TMJ involvement is uncommon but TMD is common in these patients
What are the clinical features of psoriatic arthritis?
Unilateral sudden onset episodic clinical course
Pain and tenderness of joint and masticatory muscles
Morning stiffness
Jaw fatigue
Crepitus
Occassional painful TMJ capsule swelling
Painful mandibular movements with progressive decrease of opening
In severe cases can cause ankylosis
Who most commonly gets ankylosing spondylitis?
M > F (10:1 ratio)
0.4 - 1.6% prevalence in caucasian population
20 - 30 years old
TMJ can be affected several years after onset reported that 4 - 50% have TMJ involvement
How can infectious arthritis of the TMJ arise?
TB
Syphilis
Gonorrhea
Lyme disease
Actinomycosis
Spread of local odontogenic infection through spread through pterygomandibular space. (Odontogenic infections, osteomyelitis, parotid, ear, nose, throat infections)
Direct infection through trauma or joint surgery
What risk factors increase chance of infectious arthritis?
RA
Diabetes mellitus
IV drug use
HIV
Immunosuppressives
What are the clinical features of infectious arthritis?
Prodromal period of primary systemic disease
Join pain and tenderness
Limited ROM
How is infectious arthritis managed?
Primary = treatment of infection
Secondary = supportive therapy
Important to increase range of motion of TMJ to avoid ankylosis or fibrosis.
What is metabolic arthritis?
Inflammation of joint tissues due to deposition of microcrystals in synovium can be in the form of Gout or pseudogout
Who often gets gout?
Possible genetic inheritance
Usually in men >40 years of age
What is pseudogout?
Common disease seen in individuals with other metabolic problems such as diabetes. Seen in M = F and people >40 years of age.
Does TMJ get affected often by metabolic arthritis?
Yes but rarely.
What are the clinical findings of metabolic arthritis?
Restricted mouth opening
Mild pain
Joint noises
What are the radiographic findings of metabolic arthritis?
Several years after onset leading to joint deposits.
Pseudogout deposits in joint more quickly
What are the lab findings of gout?
Elevated serum uric acid levels
Joint fluid aspirate showing opalescent fluid and polarised light shows monosodium urate crystals on microscopy
