TMJ Temporomandibular Joint

1. Temporomandibular Joint
Dr. Mohammad Amaan

2. Introduction
• The most important functions of the
Temporomandibular joint (TMJ) are:-
Mastication and speech

3. .
• The right and left TMJ form a bicondylar
articulation.
• The features that differentiate and make this joint
unique are its articular surface covered by fibro
cartilage instead of hyaline cartilage.

4. Peculiarity of TMJ
• Bilateral diarthrosis – right & left function together
1. Articular surface covered by fibrocartilage
• instead of hyaline cartilage

5. Type of joint
• Synovial joint
• Condylar variety

6. components
• Articular surfaces of Temporal bone
• Articular disc
• Mandibular condyle
Ligaments

7. Articular surface
• Upper articulating surface
(temporal bone)
• Lower articulating surface
(head of the mandible)
• The articular surface are covered by
FIBROCARTILAGE
• In between the upper and lower articulating
surface is an Intra articulating disc

8. Upper articulating surface
• Formed by the following parts of the Temporal
bone
1. Articular tubercle
2. Anterior part of the mandibular fossa
3. Posterior non articulating part formed by the
tympanic plate

9. Lower articulating surface
• Formed by the head of the mandible

10. LIGAMENTS
1. Fibrous capsule
2. The Lateral ligament
3. The Sphenomandibular ligament
4. The Stylomandibular ligament

11. 1. Fibrous capsule
• It is attached above to :-
1. The Articular tubercle
2. The circumference of the mandibular fossa (in front)
3. The squamotympanic fissure (behind)
• It is attached below to :-
1. The neck of the mandible
• The capsule is :-
-- LOOSE above the intra articular disc
-- TIGHT below the intra articular disc
• The synovial membrane lines the fibrous capsule and the neck of
the mandible

13. 2. The lateral Temporomandibular ligament
• It reinforces and strengthens the lateral part of the
capsular ligament
• It’s fibres are directed downwards and backwards
• Its attached
- Above – to the Articular tubercle
- Below – to the posterolateral aspect of the neck of
the mandible

15. 3. The Sphenomandibular ligament
• It is an Accessory ligament
• Lies on the deep plane away from the fibrous
capsule
• It is attached:-
- Above – to the spine of sphenoid
- Below – to the lingula (mandibular foramen)

16. .
• This ligament is related Laterally to the:-
1. Lateral Pterygoid muscle
2. Auriculotemporal nerve
3. Maxillary artery
• This ligament is related Medially to the:-
1. Chorda tympani nerve
2. Wall of the pharynx

18. 4. The Stylomandibular ligament
• It is an Accessory ligament
• It represents the thickened part of the Deep
Cervical Fascia (deep lamina)
• It separates the parotid gland from the
submandibular gland
• Attached :-
- Above – to the styloid process
- Below – to the angle & post. border of ramus
of mandible

20. ARTICULAR DISC
• Is an oval FIBROUS PLATE
• Present in between the upper and lower
articulating surface
• Divides the joint cavity into upper and lower
compartments
• Upper compartment – permits GLIDING
MOVEMENT
• Lower compartment – permits ROTATORY as
well as GLIDING movements

21. .
• The disc
- superior surface = concavo-convex
- inferior surface = concave
• The periphery of the disc is attached to the
fibrous capsule.
• The DISC is composed of :-
1. Anterior extension
2. Anterior thick band
3. Intermediate zone
4. Posterior thick band
5. Bilaminar region ( containing venous plexus)

23. Function of the articular disc
• It prevents friction between 2 articulating
surface
• Provides cushion like consistency
• Prevents from shock
• Fills the gap and helps in distribution of the
weight across the TMJ
• The proprioceptive fibres present in the disc
help to regulate movements of the joint

24. Relations of TMJ
LATERAL
1. Skin and fascia
2. Parotid gland
3. Temporal branch of facial nerve
Medial
1. The tympanic plate
2. Spine of sphenoid (with upper end of spine of
sphenoid)
3. Auriculotemporal and chorda tympani nerves
4. Middle meningeal artery

25. ANTERIOR
1. Lateral Pterygoid
2. Masseteric nerve and artery
POSTERIOR
1. Parotid gland (separates the TMJ from external
acoustic meatus)
2. Auriculotemporal nerves
SUPERIOR
1. Middle cranial fossa
2. Middle Meningeal vessels
INFERIORLY
1. Maxillary artery and vein

26. .
BLOOD SUPPLY / venous drainage
• Branches from :-
- Superficial temporal & maxillary artery
• Veins follows the artery
NERVE SUPPLY
• Masseteric nerve
(from the main trunk of mandibular)
• Auriculotemporal nerve
(post trunk of mandibular)

27. Movements
1. Depression (opening of mandible)
2. Elevation (closing)
3. Protrusion
4. Retrusion
5. Lateral / side to side movement