The temporomandibular joint is a synovial joint that connects the mandible to the temporal bone. It is a modified hinge joint that allows for depression and elevation of the mandible as well as protrusion, retraction, and side-to-side movements during chewing. The joint is comprised of the articular tubercle of the temporal bone above and the condyle of the mandible below. An articular disc divides the joint cavity into two compartments. Various ligaments and muscles are involved in stabilizing the joint and producing its movements.

1. Temporo-mandibular
Joint
By Dr. Piyush

2. • Introduction
• Classification/ type
• Articulating Bony surfaces
• Ligaments
• Factors which maintain stability of joint
• Associated structures (like bursa, tendinous cuff)
• Relations of joint
• Blood supply
• Nerve supply
• Movements/ Biomechanics
• Applied anatomy
How to write answer for any Joint ?
Headings

3. INTRODUCTION
• ARTICULATION OF
MANDIBLE WITH SKULL.
• PAIRED IN THE FORM OF
BICONDYLAR
ARTICULATION.
• SYNOVIAL JOINT OF
MODIFIED HINGE VARIETY
• *GINGLYMOARTHRODIA
L JOINT.

6. • Articulating Bones
• Above: Temporal bone (Articular tubercle & anterior articular
part of mandibular Fossa.
• Below: Head / Condyles of mandible ( elliptical- axis
perpendicular to the plane of ramus of mandible.)

11. • Articulating surfaces covered by Fibrocartilage
• Joint cavity divided by articular disc into 2 compartments:
• upper menisco-temporal compartment
• lower menisco-mandibular compartment.

13. • Ligaments:
• Capsular ligament
• Articular disc
• Lateral Ligament / temporo-mandibular ligament.
• Acessory ligaments: Sphenomandibular & stylomandibular
Ligament.

15. • Relations:
• Anterior: Lateral pterygoid, Temporalis & Masseteric vessels
& nerve.
• Posterior: Parotid,Superficial temporal vessels,
Auriculotemporal nerve, Ext. Acoustic meatus.
• Lateral: It is Subcutaneous.
• Medial: Lateral pterygoid, Roots of Auriculotemporal nerve
enclosing Middle meningeal Artery, Spine of shenoid and
sphenomandibular ligament , Chorda tympani nerve.

19. masseter

25. • Arterial supply: Branches of Superficial temporal And
Maxillary Arteries
• Nerve Supply: Auriculotemporal nerve & Masseteric nerve.

26. • Movements:
• Protrusion
• Retraction
• Depression
• Elevation
• Side to side chewing movements.

27. • Muscle Producing Movements
• Protrusion: Simultaneous action of Lat. & Med. Pterygoid.
• Retraction: Posterior fibres of Temporalis
• Depression: Lateral pterygoid, Geniohyoid, Mylohyoid,
Digastric; Gravity.
• Elevation: Masseter, Temporalis & Medial Pterygoid.
• Side to side Chewing: Lateral &Medial pterygoid acting
alternately with other side.

31. • Range of Movements:
• Depression/ mouth opening: 5 cm
• Protrusion: 1cm
• lateral displacement: 1cm

32. • Mechanism:
• Meniscotemporal compartment permits gliding for protrusion,
retraction and chewing movements.
• Menisco mandibular compartment permits rotatory movement.
• Axis:
• a) transverse axis for depression and elevation
• b) vertical axis for Side to side movement.

33. • Mechanism of mouth opening:
• Head of mandible And articular disc together glide forward in
menisco temporal compartment by action of Lat pterygoid.
• Simultaneously rotation of head occurs in lower compartment by
suprahyoid muscles.

34. • 3 phase:
• Initial phase (Rotation): rotation of mandibular head in lower
compartment. Axis transverse through neck
• Intermediate phase (Rolling): gliding forward of head as well
as articular disc in upper compartment. Head keeps on rotating
in lower compartment. Axis moves forward. gliding arrested by
posterior fibres of temporalis.
• Final phase (Rotation): Axis fixed and head rotates further in
lower compartment until it reaches summit of articular tubercle.

36. • Mechanism of chewing:
• Mandibular head of one side glides forward in upper
compartment & Rotation occurs in lower compartment.
• Axis being the vertical axis passing posterior border of
opposite ramus.
• Head then returns to its normal position and opposite head
repeats the movement.

38. • Factors of Stability:
• Bones: Forward displacement prevented by Articular tubercle.
• Backward displacement prevented by Post glenoid tubercles.
• Ligaments :temporo mandibular ligament prevents Backward
displacement
• Muscles: Temporalis limits protrusion. Lateral pterygoid limits
retraction.
• Position of mandible: Occlusal position is the Close pack position.

39. Applied
• Dislocation: only Forward dislocation is seen. Head
dislocated to infratemporal fossa
• Reason: Sudden spasm of Lat pterygoid during wide
opening (Yawning)
• Reduction: downward traction with chin elevation.

42. Thank you