TMJD

Question 1

Give differential diagnosis of tmj disorders

Answer 1

Infection/inflammatory - septic athritis, otitis media (leads to ankylosis)
Neoplasia (benign/malignant)
Drugs/degenerative (osteoarthritis)
Iatrogenic (Idiopathic condylar resorption, myofascial pain)
Congenital/developmental (condylar hypoplasia/aplasia, hyperplasia/ hemifacial microsomia)
Autoimmune (Rheumatoid, psoriatic, gout)
Trauma (fracture, effusion, dislocation)
Endocrine/metabolic

Question 2

What are the causes of TMJD

Answer 2

Trauma (direct or indirect - whiplash)
Bruxism
Joint laxity
Stress

Question 3

Important relevant history in arthromyalgia

Answer 3

Type of pain
Location of pain
Severity
Triggering factor
Aggravating factor
Relieving factor
Other comorbids- joint dz? Gout? Migraine? Spine problems? Fibromyalgia?

Question 4

Specific findings

Answer 4

Muscle tenderness involving muscle of mastication
Associated with localized trigger points
Limited mouth opening or range of movement
With or without joint clicking

Question 5

What are characters of internal derangements of tmj

Answer 5

Disc displacement with or without reduction
Perforation of disc/retrodiscal tissues
Degenerative changes in the disc and articulating surface

Question 6

What are the changes that occur intraarticular in tmjd

Answer 6

Disc displacement (anterior>medial>anterolateral>other)
Chondromalacia (softening, furrowing, fibrillation & ulceration, crater formation & subchondral bone exposure)
Synovitis
(acute 1 - minimal vasodilation; no hyperemia
2- moderate vasodilation; early hyperemia
3- considerable vasodilation; moderate hyperemia
4- obliteration of vascular pattern; total hyperemia
Chronic -hyperplasia & tissue folds)

Question 7

Wilkes classification of internal derangement

Answer 7

5 stages based on pain, mouth opening, disc position, anatomy

Question 8

Investigations

Answer 8

OPG - screen for bony condylar changes
TMJ view open and close mouth - assess the position of condylar head in glenoid fossa in motion
MRI - to see internal derangements or the intraarticular soft tissue pathology
Ct scan - osseous pathology
Scintigraphy - bone activity, inflammation

Question 9

Investigation finding

Answer 9

Mri - disc displacement, disc perforation, synovial inflammation,

Question 10

Objectives of tx

Answer 10

Eliminate pain
Improve function
Stable occlusion

Question 11

Treatment algorithm for TMJD or arthromyalgia WITH pain

Answer 11

1. Nonsurgical conservative therapy: soft diet; medications; occlusal appliance; physiotherapy; stress reduction technique
2. Arthrocentesis
3. Arthroscopy
4. Open joint surgery: disc repositioning (discoplasty)

Question 12

What is nonsurgical management of tmjd

Answer 12

1. soft diet
2. medications
   - nsaids - antiinflammatory & analgesia
   - steroids - antiinflammation
   - muscle relaxants - chlorobenzaprine 5mg tds
   - antidepressants - TCA - amitriptyline
   - anxiolytics - diazepam 5mg qid
3. oral appliance
   - stabilization splint - hard acrylic splint of maxilla covering all dentition, flat nonguiding surface - doesnt prevent clenching and grinding
   - repositioning splint - hard acrylic splint of maxilla with an inclined plane to guide the mandible anteriorly thereby recapturing an anteriorly displaced disk
   - modified hawley retainer - hard acrylic splint with an anterior plate where 6 anterior teeth are in contact and producing an open bite at the posterior teeth - prevents grinding and clenching
4. physiotherapy - jaw exercise, heat pack, topical spray and stretch, massage.
5. stress reduction technique

Question 13

Treatment algorithm for TMJD with LOCKING

Answer 13

1. Arthrocentesis
2. Arthroscopy
3. Open joint surgery (discoplasty/discectomy with or without replacement)

Question 14

Arthrocentesis

Answer 14

Lysis and lavage the superior joint space

Question 15

Indications of arthrocentesis

Answer 15

Acute/chronic trismus with anterior disc displacement
Chronic pain with anteriorly disc displacement that doesnt resolve with nonsurgical
Degenrative joint disease

Question 16

Technique of arthrocentesis

Answer 16

Using 2 needles for inflow and outflow
Inflow: 10-2 point anterior to midtragus - inferior to canthotragal line
Outflow: 20-10 point anterior to midtragus - inferior to canthotragal line
Lavage with minimum 100ml Hartmanns/NS
Manipulate mouth opening to break the adhesions
Intraart injection: steroids/ hyalauronic acid/ morphine/ local anesthesia

Question 17

Arthroscopy

Answer 17

Inserting scope for diagnostics or therapeutic purposes.

Diagnostics: anatomical landmarks to look at
Retrodiscal synovium - retrodiscal tissue
Posterior disc attachment
Disc
Articular eminence and glenoid fossa
Synovial drape

Therapeutic: 
Lysis and lavage (arthrocentesis)
Biopsy
Synovectomy
Freeing the adhesions 
Releasing the lateral pterygoid
Disc repositioning
Intra-articular pharmacotherapy

Question 18

Indications of arthroscopy

Answer 18

Disc derangements
Osteoarthritis
Rheumatoid arthritis
Crystal-induced arthritis
Synovial pseudotumors

Question 19

Absolute contraindications of arthroscopy

Answer 19

Ankylosis
Advanced resorption of glenoid fossa (accidental perforation into middle cranial fossa)
Infection and malignant tumors

Relative contraindications
Risk for hemorrhage
Risk of infection
Fibrous ankylosis

Question 20

Postoperative care of arthroscopy

Answer 20

Anaesthetic effect if involved facial nerve should be reassured
Postoperative analgesia
Antibiotic if infection risk is high (immunodeficiency/ prosthetic valves) if normal, no need a/b
Physiotherapy

Question 21

complications of arthrocentesis/arthroscopy

Answer 21

hemoarthrosis - venous in origin (McCain suggested protocol - to position condyle to where the bleeding is for 5mins to act as pressure)

Extravasation (of fluid into surr tissue which may lead to extensive edema of upper airway)

Broken instruments;

Otologic complications: perforation to EAM, tympanic membrane, hemotympanum, partial dislocation of malleus, hearing loss (3 case reports),

Intracranial damage;
Perforation into middle cranial fossa

facial nerve or auriculotemporal nerve injury

Infection (rare and doesn’t necessarily indicates antibiotic)

Question 22

Open joint surgery

Answer 22

Discoplasty - disc repositioning
Discectomy - removal of damaged disc
Disc replacement - interpositional grafts (temporalis fascia, cartilage)

Question 23

preauricular approach to tmj

Answer 23

1. skin along tragal line +/- temporal extension
2. subcut tissue
3. temporoparietal fascia (above ZA) and SMAS (below ZA) - STV and ATN above the fascia/ TB of FN below the fascia
4. dissection of flap for anterior retraction:
   above the ZA - superficial layer of temporalis fascia
   below the ZA - avascular plane along the external auditory cartilage
5. incision above ZA on superficial layer of TF - begins at root of ZA just in front of tragus, extending anterosuperiorly
6. fat tissue
7. deep layer of TF
8. periosteum at root of ZA
9. lateral capsule of TMJ

Question 24

Closure of tmj open surgery

Answer 24

Lateral capsule
Temporalis fascia
Subcut tissue
Skin using subcuticular

Question 25

Which joint disease produces worsening pain with function?

Answer 25

Osteoarthritis

Question 26

Which joint diseases has worse pain in the morning but improves over the day

Answer 26

Rheumatoid arthritis

Question 27

What are clinical presentation of RA?

Answer 27

``` Bilateral involvement (unlike OA, or other gout dz which is usually unilat) Pain with limited range of movement Preauricular swelling Pain which is worse in morning which improves over course of the day Late presentations: - condylar resorption - class 2 malocclusion - AOB - ankylosis ```

Question 28

Radiographic findings of RA

Answer 28

Bilateral involvement of the joint Condylar flattening Cortical erosion Loss of ramus height

Question 29

Presentation of Juvenile RA

Answer 29

``` <12 years Bilateral Flattening and erosion of radiograph Loss of ramus height Aperthognathia (AOB) Skeletal class 2 with bird face deformity Positive RF (20%) and ANA (60-80%) ```

Question 30

What are lab tests for rheumatoid arthritis

Answer 30

Serological markers: ACPAs (anti-citrullinated protein antibodies) RF (rheumatoid factors) ANAs (antinuclear antibodies) HLA Dw5, DRw ESR: to indicate/monitor disease progression or clinical course

Question 31

Features of osteoarthritis

Answer 31

Narrowing of joint space Cortical erosions Osteophyte formation Subchondral cysts

Question 32

What is treatment of RA.

Answer 32

Disease management: NSAIDs, steroids, soft diet, physiotherapy, immunosuppressive drugs - referral to rheumatology Structural defect mx: arthrocentesis/arthroscopy/open joint surgery, ogs

Question 33

What are arthrotic changes in arthritis (OA)

Answer 33

Erosion Sclerosis Flattening Reduced joint space

Question 34

Management of OA

Answer 34

Conservative: soft diet, medications, occlusal splint, physiotherapy. Surgical: removal of osteophytes and smoothening of erosions (Only indicated if conservative mx not effective after 6 months)

Question 35

What is Reiters syndrome

Answer 35

Inflammatory arthritis that develops from an infection else where in the body (cross reactivity) Classic triad: Arthritis (cannot climb) Uveitis (cannot see) Urethritis (cannot pee) Labs: RF negative

Question 36

Is the posterior disc vascularized and innervated?

Answer 36

Yes. | As it continues to retrodiscal tissues that contains vessels and nerves

Question 37

What is Eagle syndrome

Answer 37

Elongation of styloid process that causes pain in the neck

Question 38

What is Idiopathic condylar resorption?

Answer 38

Bilateral symmetric progressive condylar resorption Followed by stabilization without further loss of height down to sigmoid notch Occuring in young teenage females at pubertal growth spurt

Question 39

Presentation of ICR?

Answer 39

``` Mild symptoms of TMJD without restriction in function Thinning and flattening of the condyle Loss of posterior ramus height Anterior open bite Mandibular retrusion Class 2 ```

Question 40

Diagnosis of ICR is made based on

Answer 40

Bone scintigraphy (Technetium 99) to assess activity inflammation, resorption or stabilization of disease

Question 41

Treatment controversy of ICR

Answer 41

Treatment to restore function, stable occlusion and aesthetic - conservative tx with splints, medications and physiotherpay if symptomatic, and to stabilize progress of disease - orthognathic surgery requiring BSSO to advance mandible once disease has been stabilized - associated with an increase risk of relapse due to reactivation of ICR - TMJ reconstruction/replacement is considered gold standard with complete removal of disease - controversial as to be too invasive surgery

Question 42

Methods to ensure stabilization of ICR?

Answer 42

1. Severity of AOB whether increasing or similar 2. Dentals casts to allow comparisons from previous review dates 3. Lateral cephalogram, able to assess the condyle and extension of skeletal discrepancy, able to measure post ramus height 4. Opg to look at changes in the condylar flattening or erosion 5. Bone scan with Technetium to look for activity of inflammation, growth or condylysis (destruction)

Question 43

What are indications for TMJ reconstruction?

Answer 43

``` End stage joint disease of OA or RA (usually presents with severe pain and severe resorption) Adult ankylosis Severe ICR with total loss of condylar Neoplasm of TMJ requiring resection Avascular necrosis of the tmj ```

Question 44

Contraindications of total joint replacement

Answer 44

``` Active infection Inadequate local bone Known allergy to TJR material (nickel, titanium) Pediatric (or still growing) Inability to under rehabilitation ```

Question 45

Complications of Total joint replacement?

Answer 45

Failure of hardware - breakage of component - loosening or displacement of hardware - wearing through of fossa material - prosthesis does not fit - fixation failure Biologic - infection - immune response (allergy or foreign body reaction) Operative related - Nerve injury (facial nerve, ATN) - otologic complications (hemotynpanum, perforation of EAC or tympanic membrane) - bleeding (superficial temporal artery during flap approach; masseteric artery/internal maxillary artery during resection of condyle which is located 20mm below condylar head; pterygoid venous plexus, middle meningeal artery) - intracranial injury (glenoid fossa thickness is 0.9mm) - rarely reported

Question 46

Types of alloplastic joint prosthesis and their differences

Answer 46

1. Prefabricated (stock prosthesis) - allows 1 stage procedure to resect and reconstruct 2. Custom prosthesis - requires 2 stage procedure, resection - ct scan for custom joint fabrication - reconstruction