TMJ Disorders (Prof Ayoub)

Question 1

What is the aetiology of TMJD

Answer 1

macrotrauma
microtrauma
occlusal factors
anatomical factors

Question 2

What is macrotrauma

Answer 2

one sudden incident

Question 3

What is microtrauma

Answer 3

chronic joint overloading, secondary to stress related repetitive clenching or bruxism

Question 4

What are occlusal factors

Answer 4

o Deep bite
o Occlusal disharmony e.g high filling
o Lack of teeth

Question 5

What are examples of anatomical factors

Answer 5

class 2 jaw relation (excessive trauma)

Question 6

What are symptoms of TMD

Answer 6

 Pain may be
o Muscular
o Capsular
o Intracapsular ‘disc’
 Reduced mobility
 TMJ clicking/locking

Question 7

What are the 3 parts of the articular disc

Answer 7

anterior part (attached to LP)
posterior part
bilaminar zone

Question 8

What is teh bilaminar zone formed of

Answer 8

collagen fibres, part of which are attached to the posterior part of the condyle and the other parts to the posterior part of the eminence and the elastic fibres are what bring the disc back again

Question 9

What does repeated pulling of the disc result in

Answer 9

loss of recoil elasticity of the collagen fibres of the bilaminar zone

Question 10

What is derangement of the joint

Answer 10

 The lateral pterygoid will move the disc forward but the disc may be unable to go back, this is known as derangement of the joint

Question 11

What type of joint is TMJ

Answer 11

fibrocartilage

Question 12

What movement is the upper compartment involved in

Answer 12

translation

Question 13

What movement is the lower compartment involved in

Answer 13

rotation

Question 14

What help resist the load on the TMJ

Answer 14

Cartilage, synovial fluid, joint shape, muscles and ligaments

Question 15

What deos the articular cartilage consist of

Answer 15

Chondrocyts
Collagen fibres in proteoglycan matrix

Question 16

What does inflammatory disease do

Answer 16

produces proteases which degrade proteoglycans

Question 17

What is the first phaes of clicking

clicking happens in 2 phases

Answer 17

when the bilaminar zone can bring the disc back, the patient says they feel a click/grinding and this is anteriorly dislocated with reduction

Question 18

What is the second phase of clicking

Answer 18

When the patient cannot open their mouth and is known as anterior dislocated without reduction where the bilaminar zone gives up and cannot bring back the disc

Question 19

What are the innervated parts of the TMJ

Answer 19

capsule, synovial tissue and subchondral bone

Question 20

What can compressive forces do to the TMJ

Answer 20

damage proteoglycans which protect collagen

Question 21

What can shearing forces do to the TMJ

Answer 21

break up collagen fibrils

Question 22

What are the degenerative changes

Answer 22

 Cartilage degeneration: chondromalacia/collagen fibrillation/subchondral bone exposure
 Disc perforation
 Multiple adhesions
 Adhesive capsulitis
 Osteophytes
 Flattening of condyle and eminence
 Subchondral cysts

Question 23

What does conservative management consist of

Answer 23

• counselling
• pain management
• joint rest
• muscle relaxation
• physical therapy
• restoration of occlusal ability

Question 24

What are functions of a bite raising appliance

Answer 24

 Eliminates occlusal interferences so acts as a habit breaker (main function)
 Prevents condyle from rotating so far posteriorly (in the area of the bilaminar zone where there is maximum inflammation) in the glenoid fossa
 Reduces loading on TMJ

Question 25

What are the possible investigations for TMJ

Answer 25

arthrogram
MRI
arthroscopy
arthroscopic procedures

Question 26

What is an arthrogram

Answer 26

o Use of contrast medium
o Contrast cannot be injected into the disc

Question 27

What is arthroscopy

Answer 27

o Looking inside joint space with scope into superior compartment
o Can’t go into the inferior compartment as its too narrow
o Can be used to look for perforation

Question 28

What are intra and post operative complications of TMJ surgery

Answer 28

 Iatrogenic scuffing
 Broken instruments
 Middle ear perforation
 Glenoid fossa perforation
 Extravasation
 Haemorrhage
 Hemarthrosis
 Damage to Vn & VIIn
 Infection
 Disocclusion
 Laceration of EAM
 Perforation of tympanic membrane

Question 29

What is post operative management

Answer 29

 Joint rest – soft diet, avoid widely opening
 Pain management
 Physical therapy
 Restoration of occlusal stability

Question 30

What are the possible surgical procedures

Answer 30

disc plication
eminectomy
high condylar shave condlyectomy
meniscectomy
condylectomy
reconstructive procedures

Question 31

What is disc plication

Answer 31

o Restoring normal condyle-disc relationship

Question 32

What is eminectomy

Answer 32

removing the eminence

Question 33

What is high condylar shave condylotomy

Answer 33

o 2mm of condylar head removed/shaved

Question 34

What is meniscectomy

Answer 34

o Remove disc completely

Question 35

What is condylectomy

Answer 35

o Removal of the condyle

Question 36

What are the indications for TMJ reconstruction

Answer 36

joint destruction
ankylosis
developmental deformity
tumours

Question 37

What is type 1 ankylosis

Answer 37

flattening deformity of condyle, little joint space & extensive fibrous adhesions

Question 38

What is type 2 ankylosis

Answer 38

bony fusion at outer edge of articular surface

Question 39

What is type 3 ankylosis

Answer 39

marked fusion bone between upper part of ramus of mandible & zygomatic arch

Question 40

What is type 4 ankylosis

Answer 40

entire joint replacement by mass of bone