The temporomandibular joint (TMJ) allows movement of the mandible for speech and chewing. It is located on each side of the head between the temporal bone and mandible. The TMJ is a complex synovial joint that contains articular surfaces covered by fibrocartilage. An articular disc divides the joint cavity into upper and lower compartments. Various ligaments and muscles work together to enable movements like depression, elevation, protraction, and retraction of the mandible. Disorders of the TMJ can cause conditions like dislocation of the mandible or ankylosis.

1. Lecture By:
Dr. Chitransha
TEMPOROMANDIBULAR
JOINT

2.  On each side of the head, between
temporal bone and mandible, that
allows the movements of the
mandible for speech and
mastication.

3.  It is described as a complex, biaxial,
synovial & bicondylar joint.
 Also known as the craniomandibular
joint or bilateral diarthroidial joint.

4. ARTICULAR SURFACES
The upper articular surface is formed
by:
1. Articular fossa (anterior part of
Mandibular Fossa )and
2. Articular tubercle of the temporal
bone.
 This surface is concavo-convex from
behind forwards.

6.  The inferior articular surface is
formed by:
1. Head (condyle) of the mandible.
 This surface is elliptical in shape.
The articular surfaces are covered
by fibrocartilage and not by hyaline
cartilage, hence TMJ is an atypical
synovial joint.

8. Gross Anatomy of TMJ
 BONY
COMPONENTS
Condylar Head
Articular Fossa
Articular
tubercle
 SOFT TISSUE
COMPONENTS
Articular Disc
Synovial fluid
Ligaments

11.  The cavity of TMJ is divided by an
intra-articular disc of fibrocartilage
(MENISCUS) into
upper menisco-temporal
lower menisco-mandibular
compartments.

12. Articular Disc
 The articular disc is an oval plate of
fibrocartilage.
 The periphery of the disc is attached
firmly to the fibrous capsule.

13.  The ligaments are
1. Fibrous Capsule
2. Temporomandibular
3. Sphenomandibular
4. Stylomandibular Ligaments

14. Fibrous capsule
 It is a fibrous sac to enclose the joint
cavity.
 It is attached above to the articular
tubercle, the circumference of
articular fossa, and the
squamotympanic fissure and below to
the neck of mandible.
 The synovial membrane lines the
inner aspect of the fibrous capsule

16. Lateral (temporomandibular)
ligament
 It is a true ligament and formed as a
result of thickening on the lateral
aspect of the capsular ligament.
 It is attached above to the articular
tubercle and below to the
posterolateral aspect of the neck of
the mandible.
 The lateral ligament strengthens the
lateral aspect of the capsule.

18. Sphenomandibular ligament
 It is attached above to the spine of
the sphenoid and below to the lingula
of the mandible.
 The sphenomandibular ligament
represents the unossified
intermediate part of the sheath of the
Meckel’s cartilage of the first
pharyngeal arch.
 It becomes accentuated and taut
when the mandible is protruded.

19. Stylomandibular ligament
 It is attached above to the lateral
surface of the styloid process and
below to the angle of the mandible.
 The stylomandibular ligament is
formed due to thickening of the
investing layer of deep cervical fascia,
which separates the parotid and
submandibular glands.
 This ligament also becomes taut
when the mandible is protruded.

21. Relations of TMJ

22. Lateral
 Skin and fasciae.
 Parotid gland.
 Temporal branches of the facial
nerve.

23. Medial
 Tympanic plate separating it from
internal carotid artery.
 Spine of sphenoid.
 Auriculotemporal nerve.
 Middle meningeal artery.
 Sphenomandibular ligament.
 Chorda tympani nerve.

25. Anterior
 Lateral pterygoid.
 Masseteric nerve and vessels.

26. Posterior
 Postglenoid part of parotid gland
separating it from external auditory
meatus.
 Superficial temporal vessels.
 Auriculotemporal nerve

27. NERVE SUPPLY
 Auriculotemporal nerve
 Masseteric nerve

28. BLOOD SUPPLY
 Maxillary artery.
 Superficial temporal artery.
Veins follow the arteries.

29. LYMPHATIC DRAINAGE
 The lymph from TMJ is drained into:
 Superficial parotid (preauricular)
nodes.
 Deep parotid nodes.
 Upper deep cervical nodes.

30.  The movements occurring at the
temporomandibular joints are:
1) Depression
2) Elevation
3) Protraction
4) Retraction
5) Side to side (Chewing)
movements

31. Muscles Producing
Movement
 Depression (Opening of Mouth)
It is produced mainly by lateral
Pterygoid helped by gravity.
The digastric, geniohyoid, and
mylohyoid muscles help when the
mouth is opened widely or against
resistance.

32.  Elevation (Closing the Mouth)
It is caused by medial pterygoid,
masseter, and temporalis (vertical
fibres).

33.  Protraction
 Lateral and medial pterygoids and
superficial fibres of masseter.

34.  Retraction
It is done by posterior fibres of
temporalis.
Assisted by middle and deep fibres
of the masseter, the digastric and
geniohyoid muscles.

35.  Side-to-side (Chewing) Movements:
 These movements are performed
by alternate contraction of medial
and lateral pterygoids on each side.

36. APPLIED
 Dislocation of mandible
 Ankylosis
 During surgery of
temporomandibular joints, the facial
nerve should be preserved.