TEMPROMANDIBULAR
JOINT
TMJ: is a bilateral joints permits
the mandible to move as a unit
with two functional patterns:
• Hinge (inferior portion)
• Translation (superior portion)
(ginglymoarthroidal joint)
(compound joint)
it has four anatomical parts:
1- condyle
2- articular fossa
3- articular disc
4- articular capsule
The Synovial fluid:
Consist of small amounts of a clear, straw-colored viscus
fluid. It is an infiltrate of the blood diffused out from the
rich capillary network of the synovial membrane.
Function:
1- lubrication by two mechanisms: boundry lubrication
weeping lubrication
2- nutrition.
3- clear the tissue debris.
Ligaments :
1-collateral(discal)
2-capsular
3-tempromandibular
4-sphenomandibular
5-stylomandibular
Muscles of mastication:
1- masseter: superficial & deep
2- temporalis
3- medial pterygoid
4- lateral pterygoid: superior & inferior
- Digastric muscles is not a muscle of
mastication but it play an important role in
mandibular function.
Nerve supply: the mandibular division of the
trigeminal nerve.
Vascular supply:
superficial temporal artery--- post
middle meningeal artery--- ant
internal max.artery---- inf
deep auricular
Anterior tympanic
Ascending pharengeal arteries
Control of TMJ movements:
-Vertical jaw reflexes:
1-jaw jerk
2-jaw opening
3-jaw unloading
-horizontal jaw reflexes
Age changes of theTMJ:
1- Flattened condyle
2- osteoporosis of the condyle bone.
3- Thickning of the fibrous covering of the condyle.
4- Thinning of the cartilagenous zone of condyle.
5- Thinning of the disc
6- Fibrotic synovial folds
7- Thickening of the b.v. walls
8- Decrease the number of nerves
These age changes lead to:
-Decrease in the synovial fluid formation
-Impairment of motion due to decrease in
the disc and capsule extensibility
-Decrease the resilience during mastication
due to chondroid changes into
collagenous elements
-Dysfunction in older people
Disorders
of TMJ
Disorders of the TMJ:
1- limitation of movement:
- temporary
- permanent
2- dislocation
3- pain
4- hyperplasia
5- neoplasm
6- loose bodies in the TMJ
1-limitation of mandibular movement: due to:
a-intracapsular causes:
Infective arthritis
Juvenile arthritis
Traumatic arthritis
Intracapsular condyle fracture
b-pericapsular causes:
Irradiation
Dislocation
Condylar neck fracture
Infection of adjacent tissues
c-muscular:
Tmj dysfunction syndrome
Myalgia due bruxism
Haematoma from ID block
Tetanus
d-Others:
Oral submucous fibrosis
Systemic sclerosis
Zygomatic & maxillary fracture
Drugs
Craniofacial anomalies involving the joint
Limitation of TMJ movements:
Temporary
(trismus)
persistent
(ankylosis)
1-Temporary (trismus): due to:
• infection & inflammation in or near the joint
• Injuries
• tetanus & tetany
• TMJ dysfunction syndrome
• drugs
• hysterical
2-persistent (Ankylosis)
Intracapsular
(true)
Mechanical
Extracapsular
interfere(pseudo)
(false)
1-trauma:condyle
fracture
2-neoplasm:
osteochondroma
3-infection:
osteomylitis
4-arthritis
5-miscellaneous:
Synovial
chondromatosis
1-trauma:zygoma
fracture
2-neoplasm:
osteosarcoma
3-hyperplasia of
the coronoid
4- miscellaneous:
Congenital
anomalies
1-trauma:
Post.dislocation
2-neoplasm:
fibrosarcoma
3-infection:
Periarticular
suppuration
4-miscellaneous:
submucous
fibrosis
2-Dislocation: due to:
-blow on the jaw
-forceful extraction
-while yawning
-epileptic pt
recurrent dislocation is a typical feature of
ehler-danlos & marfan’s syndrome or
there may be no systemic disorder.
Types of displacement:
1-anterior disc displacement with reduction:
Joint noise, pain, clicking and full range of movements
2-acute anterior disc displacement without reduction:
Acute onset of limitation of opening with pain & deviation to
the affected side, history of clicking
3-chronic anterior disc displacement without reduction:
Limitation of opening for variable period,history of clicking
3-Pain in or around the joint: due to:
• injury
• infection & inflammation
• vascular disease e.g: cranial arteritis
• muscle spasm e.g: pain dysfunction syndrome
• rheumatoid & other arthritis
• salivary gland disease e.g: parotid neoplasm
• ear disease e.g: otitis media, externa
4-Hyperplasia:
Is rare unilateral overgrowth of the condyle.
It causes: facial asymmetry, deviation of the jaw to
the unaffected side on opening and crossbite.
Treated by:
-If it is stabilized at the end of puberty --- corrective
osteotomies to restore occlusion & facial
asymmetry
-If it is still active --- intracapsular condylectomy
5-Neoplasms: (rare):
• osteochondroma
• osteoma
• chondroma
6-Loose bodies in the TMJ: (rare):
• osteochondritis disssecans:
due to trauma
• synovial chodromatosis
benign neoplasm
Examination:
1-joint examination: static: palpation
x.rays ( tomography)
dynamic: mobility limitation
sounds
2-muscle examination: palpation
movement limitation
pain on movements
3-occlusal examination: study cast
facebow regestration
Examination of the TMJ
Management:
Goals:
- decreased pain
- decreased loading
- restored function
- restored daily activities
Management options:
1-Pt.education & palliative home care:yawning
2-Behaviour modifications: habits
3-Drug therapy: e.g: NSAID, analgesics
4-Exercise therapy
5-Splint therapy
6-Occlusal therapy
7-mobilization
8-Physical agents: heat,cold,muscle relaxation
9-Other therapy: joint surgery, orthodontics.
Thank you