The temporomandibular joint (TMJ) connects the temporal bone of the skull to the mandible. It contains an articular disc that separates the joint into upper and lower compartments. The condyle of the mandible articulates with the mandibular fossa in the lower compartment and glides forward in the upper compartment. The articular disc allows for this movement and is innervated by the auriculotemporal and masseteric nerves. Disorders of the TMJ can cause sounds, locking, or pain and are sometimes caused by bruxism or arthritis.

1. Temporomandibular Joint
(TMJ)
CHAPTER 22

2. Anatomy
Joint is the joining together of two bones
Temporomandibular joint (TMJ) is articulating
joint between temporal bone (skull) and mandible
(lower jaw)
Bilateral movement of right and left sides
interrelated and function as single unit
The articular disc separates the joint into upper and
lower compartments

3. Anatomy
The condoyle of the mandible articulates with the
mandibular (glenoid) fossa
Location is the posterior slope of the articular
eminence and anterior portion of the mandibular
fossa
Does not fit into the center of the mandibular fossa
but rests near the articular (eminence) tubercle
Articular disc (meniscus) rests between them

4. Anatomy

5. Anatomy
The articular disc is a pad of dense fibrous connective
tissue that is thickest at the posterior ends, thinnest in
the middle, and thicker again at the anterior end.
It separates the TMJ into upper and lower joint
compartments.
Laterally and medially, the disc is attached to the condyle
itself, so that whenever the condyle glides forward and
backward the disc moves with it.

6. Anatomy
The condyle and articular eminence are covered
by dense connective tissue
Contains no blood vessels or nerves
Nourished and lubricated by synovial fluid
Joint is covered by a thick fibrous capsule
The articular disc and capsule are connected by a
retrodiscal pad
A pad of loose connective tissue that allows for
anterior movement of the joint

7. Anatomy

8. Nerve and Blood Supply
Innervation supplied by two nerves
Auriculotemporal and Masseteric
Branches of mandibular nerve (V3)
Blood supply provided by branches of
superficial temporal and maxillary arteries

9. Movement
Two types of movement in TMJ
Hinge motion occurs in lower joint compartment
between the disc and the condoyle
Anterior gliding takes place in the upper joint
compartment between the disc and the temporal
bone
The lateral pterygoid muscle causes the forward
movement

10. Movement
Closing of the mouth is
accomplished by the lateral
pterygoid muscle, which
controls posterior movement
of disc

11. Clinical Considerations
An Internal Derangement occurs when the disc
becomes stuck or displaced.
As the condyle rotates and translates forward down
the slope of the articular eminence, the disc should
stay interposed between these bones.
If it becomes displaced or stuck, sounds of clicking,
popping or crepitus (crunching) may result.

12. Clinical Concerns
Catching or locking of the jaw, subluxation
The condoyle is displaced anteriorly and cannot be
returned voluntarily to normal position
Temporomandibular disorder (TMD), characterized
by muscle soreness
Bruxism (teeth grinding) from stress or tension are
usual causes

13. Clinical Concerns
Inflammation - arthritis may result from
wear or tear within the joint
Can also be a result of systemic disease
like rheumatoid arthritis
Cortisone is used to alleviate the pain of
arthritis

14. Clinical Concerns

15. TMD
https://youtu.be/mB468Jh9aAY
https://youtu.be/Cj3GVRlrgEQ

16. Suggested Homework
Answer the questions on pages 294-
295 in your textbook.
Complete pages 76-81 in your coloring
book