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
it has four anatomical parts:
2- articular fossa
3- articular disc
4- articular capsule
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.
1- lubrication by two mechanisms: boundry lubrication
3- clear the tissue debris.
1- masseter: superficial & deep
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.
superficial temporal artery--- post
middle meningeal artery--- ant
internal max.artery---- inf
Ascending pharengeal arteries
-Vertical jaw reflexes:
-horizontal jaw reflexes
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
-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
1- limitation of movement:
6- loose bodies in the TMJ
Intracapsular condyle fracture
Condylar neck fracture
Infection of adjacent tissues
Tmj dysfunction syndrome
Myalgia due bruxism
Haematoma from ID block
Oral submucous fibrosis
Zygomatic & maxillary fracture
Craniofacial anomalies involving the joint
-blow on the jaw
recurrent dislocation is a typical feature of ehler-danlos & marfan’s syndrome or there may be no systemic disorder.
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
Is rare unilateral overgrowth of the condyle.
It causes: facial asymmetry, deviation of the jaw to the unaffected side on opening and crossbite.
-If it is stabilized at the end of puberty --- corrective osteotomies to restore occlusion & facial asymmetry
-If it is still active --- intracapsular condylectomy
due to trauma
1-joint examination: static: palpation
x.rays ( tomography)
dynamic: mobility limitation
2-muscle examination: palpation
pain on movements
3-occlusal examination: study cast
- decreased pain
- decreased loading
- restored function
- restored daily activities
1-Pt.education & palliative home care:yawning
2-Behaviour modifications: habits
3-Drug therapy: e.g: NSAID, analgesics
8-Physical agents: heat,cold,muscle relaxation
9-Other therapy: joint surgery, orthodontics.