Temporomandibular Joint

1. TEMPOROMANDIBULAR
JOINT
Made by:- Dr. Ratna Priya
M.D.S first year
Public Health Dentistry

2. CONTENTS
 Introduction
 Definition
 Peculiarity of Temporomandibular Joint
 Development of Temporomandibular Joint
 Components of Temporomandibular Joint
 Relations of Temporomandibular Joint

3.  Vascular Supply of Temporomandibular Joint
 Nerve Supply of Temporomandibular Joint
 Movements of Temporomandibular Joint
 Age Changes of Temporomandibular Joint
 Applied Aspects
 Summary
 References

4. INTRODUCTION
 The most important functions of the temporomandibular joint (TMJ)
are mastication and speech and are of great interest to dentists,
orthodontists, clinicians, and radiologists.
 The right and left TMJ form a bicondylar articulation and ellipsoid
variety of the synovial joints similar to knee articulation.

5.  The common features of the synovial joints exhibited
by this joint include a disk, bone, fibrous capsule,
fluid, synovial membrane, and ligaments. However,
the features that differentiate and make this joint
unique are its articular surface covered by
fibrocartilage instead of hyaline cartilage.

6. DEFINITION
 The TMJ is a ginglymoarthrodial joint, a term that is
derived from ginglymus, meaning a hinge joint,
allowing motion only backward and forward in one
plane, and arthrodia, meaning a joint of which permits a
gliding motion of the surfaces.

7. Temporomandibular
joint

8. PECULIARITY OF TEMPOROMANDIBULAR JOINT
1. Bilateral diarthrosis — right & left function together
2. Articular surface covered by fibrocartilage instead of
hyaline cartilage
3. Only joint in human body to have a rigid endpoint of
closure that of the teeth making occlusal contact.
4. In contrast to other diarthrodial joints TMJ is last joint to
start develop, in about 7" week in-utero.
5. Develops from two distinct blastema.

9. DEVELOPMENT OF TEMPOROMANDIBULAR
JOINT
There are three stages:
•Blastemic Stage – week 7-8
•Cavitation stage – 9- 11
•Maturation stage – 12 - 17

10.  The first is the blastematic stage (weeks 7-8 of development), which
corresponds with the onset of the organization of the condyle and the
articular disc and capsule. During week 8 intramembranous
ossification of the temporal squamous bone begins.
 The second stage is the cavitation stage (weeks 9-11 of development),
corresponding to the initial formation of the inferior joint cavity (week
9) and the start condylar chondrogenesis. Week 11 marks the initiation
of organization of the superior joint cavity.
 The third stage is the maturation stage (after week 12 of development).

11. COMPONENTS
 Articular Surfaces
 Ligaments
 Articular Disc

12. Articular Surfaces
The upper articular surface is formed by the following parts of the
temporal bone:
a) Articular tubercle
b) Anterior part of mandibular fossa
The inferior articular surface is formed by the head of the
mandible.
The articular surfaces are covered with fibrocartilage.

13. Ligaments
The ligaments are the fibrous capsule, the lateral ligament, the
sphenomandibular and the stylomandibular ligament.
1) The Fibrous Capsule:
It is attached above to the articular tubercle, the circumference of
the mandibular fossa and the squamotympanic and below the
neck of mandible.
2) The Lateral or Temporomandibular ligament:
These fibres are directed downwards and backwards.
Attachment: above to the articular tubercle and below to the
posterolateral aspect of the neck of the mandible.

14. 3) The sphenomandibular ligament:
An Accessory ligament lying on a deep plane away from the fibrous
capsule.
Attachment: Superior to the spine of the spenoid bone, Inferior to the
lingula of mandibular foramen.
It is the remnant of the dorsal part of Meckel’s Cartilage.
The ligament is related laterally to:
• Lateral Pterygoid muscle
• Auriculotemporal nerve
• Maxillary Artery

15. It is related medially to:
 Chorda Tympani nerve
 Wall of pharynx.
4)The Stylomandibular Ligament:
Another accessory ligament. It separates the parotid and
submandibular salivary glands.
Attachment: above to the lateral surfaces of the styloid
process, below to the angle and the adjacent part of the
posterior border of the ramus of mandible.

17. ARTICULAR DISC
 The articular disc is the most important anatomic structure
of the TMJ.
 It is a biconcave fibrocartilaginous structure located
between the mandibular condyle and the temporal bone
component of the joint.
 Its functions to accommodate a hinging action as well as
the gliding actions between the temporal and mandibular
articular bone.

19. RELATIONS OF TEMPOROMANDIBULAR JOINT
Lateral
a) Skin and Fascia
b) Parotid Gland
c) Temporal branches of Facial nerve

20. Medial
a) The tympanic plate
b) Spine of the sphenoid bone
c) Auriculotemporal and chorda tympani nerves
d) Middle meningeal artery

21. Anterior
a) Lateral pterygoid
b) Massetric nerve and artery

22. Posterior
a) Parotid gland separating from external auditory meatus
b) Superficial temporal vessels
c) Auriculotemporal nerve

23. Superior
a) Middle cranial fossa
b) Middle meningeal vessels

24. Inferior
a) Maxillary artery and vein

25. BLOOD SUPPLY
Branches of External Carotid Artery
 Superficial Temporal artery
 Deep auricular artery
 Anterior tympanic artery
 Ascending pharyngeal artery
 Maxillary artery
The Blood supply to TMJ is only Superficial,i.e. there is no blood supply
inside the capsule.
TMJ takes its nourishment from the Synovial Fluid.

26. NERVE SUPPLY
 Auriculotemporal Nerve
 Massetric Nerve

27. MOVEMENTS OF TMJ
The movements of TMJ are:
• Protrusion – Protraction of the chin
• Retraction – Retraction of the chin
• Elevation – Closing of the mouth
• Depression – opening of the mouth
• Lateral / Side to side movement or grinding – Chewing
• Rotational / Hinge movement
• Translational Movement

30. AGE CHANGES IN TMJ
 Condyle: - Becomes more flattened
- Fibrous capsule becomes thicker.
- Osteoporosis of underlying bone.
- Thinning or absence of cartilaginous zone.
 Disk: - Becomes thinner
- Shows hyalinization and chondroid changes.
 Synovial fold: - Become fibrotic with thick basement membrane
 Blood vessels and nerves: - Walls of blood vessels thickened.
- Nerves decrease in number

31. These age changes lead to:
-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

32. APPLIED ASPECTS
1) Ankylosis
2) MPDS – Myofunctional Pain Dysfunction Syndrome
3) Trismus
4) Bruxism
5) Dislocation
6) Subluxation

33. Some common functional problems associated with TMJ include:
 Jaw stiffness with difficulty opening,
 Jaw Deviation with Opening,
 Clicking,
 Crepitus (grinding sound),
 Intermittent Closed Lock
 Closed Lock.

34. Ankylosis
Temporomandibular joint (TMJ) ankylosis is a pathologic condition
where the mandible is fused to the fossa by bony or fibrotic tissues.
This interferes with mastication, speech, oral hygiene, and normal life
activities, and can be potentially life threatening when struggling to
acquire an airway in an emergency.

35. Types of TMJ Ankylosis: (given by Sawhney 1986)
I. Type 1
II. Type 2
III. Type 3
IV. Type 4

36.  Type 1 - non-bony ankylosis of the joint with an almost-normal
joint space and without bony fusion or a radiolucent line.
 Type 2 - lateral bony ankylosis of the joint with lateral bony
fusion and a radiolucent line inside the fusion area
 Type 3 - complete bony ankylosis of the whole joint
 Type 4 - extensive bony ankylosis with no clear definition of the
joint

37. Etiology:
 Trauma
 Infection/ Inflammation
 Iatrogenic
 Arthritis

38. CLINICAL FEATURES:
Unilateral Ankylosis – Restricted mouth opening.
- Deviation of the mandible towards the ankylosed
side.
- Facial Asymmetry
- Roundness of the face on the affected side.
- Flat and elongated face on the unaffected side.
Bilateral Ankylosis - Bird face deformity will be seen.
- Minimum or no movement of the mandible.
- Multiple carious teeth.

39. - Poor oral hygiene.
- Bad Odour
- Obstructive sleep aponea
INVESTIGATION - X- rays like OPG and CT scan can be done
In radiograph, the fibrous or bony mass will appear as radiopaque.
MANAGEMENT - a) Gap Arthroplasty
b) Interpositional arthroplasty
c) KABAN’s protocol

40. a) Gap arthroplasty- It is a surgical procedure to treat TMJ ankylosis. A
gap is created between mandible and temporal bone by removing the
ankylotic mass. There is one drawback of ankylosis might recur.

41. b) Interpositional arthroplasty- It is a standard surgical procedure. In
which a gap is created of around 1 – 1.5 cm between the condyle and
temporal bone by removing the ankylosed mass and then placing an
interpositional material to prevent ankylosis. Temporalis myofascial
flap is a preferable choice for inter-positional gap arthroplasty.
The ankylotic mass has been classified into three classes:
 Class 1: Ankylotic bony mass restricted to the mandibular condyle and
glenoid fossa.
 Class 2: Ankylotic bony mass extends out of the glenoid fossa
 Class 3: Extension into the middle cranial fossa.

42. Steps of Intrapositional Arthroplasty:
 Classical pre-auricular Alkayat Bramely’s incision is made

43.  Ankylotic mass is removed

44.  Gap arthroplasty is done

45.  Temporalis myocutaneous fascia flap is partially cut

46.  Interpostional gap arthroplasty with rotation of temporalis
myocutaneous fascia flap is done.

47.  Primary closure and surgical drain in place is done.

48.  Post-operative maximum mouth opening is then checked

49. c) KABAN’s Protocol- Kaban has given this surgical approach.
Steps:
 Early surgical intervention.
 Aggressive resection: A gap of at least 1 to 1.5 cm should be
created.
 The coronoidectomy on the same side should be carried out and
The temporalis muscle attachments are severed by carrying out
temporalis myotomy

50.  Contralateral coronoidectomy and temporalis myotomy is
carried out, if maximum incisal opening is less than 35 mm.
 Lining of the glenoid fossa region with temporalis fascia.
 Reconstruction of the ramus with a costochondral graft.
 Early mobilization and aggressive physiotherapy for the period of
at least six months postoperatively

52. MPDS (Myofacial Pain Dysfunction
Syndrome (MPDS)
MPDS is a pain disorder, in which unilateral pain is referred from
the trigger points in myofascial structures, to the muscles of the
head and neck. Pain is constant, dull in nature, in contrast to the
sudden sharp, shooting, intermittent pain of neuralgias (chronic
pain). But the pain may range from mild to intolerable.
Clinical Characteristics:
1. A zone of reference
2. Trigger points in muscles
3. Occasional associated symptoms
4. Presence of contributing factors

53. Etiology:
1. Muscular hyperfunction.
2. Physical disorders .
3. Injuries to the tissues.
4. Parafunctional habits.
5. Disuse.
6. Nutritional problems.
7. Physiological stress.
8. Sleep disturbances.

54. Cardinal symptoms of MPDS:
i. Pain or discomfort (unexplained nature), anywhere about the
head or neck.
ii. Limitation of motion of the jaw.
iii. Joint noises—grating, clicking, snapping, etc.
iv. Tenderness to palpation of the muscles of mastication

55. Follow-7 R’s for occlusal rehabilitation
1. Remove—extract
2. Reshape—grind
3. Reposition—orthodontia/orthognathic surgery
4. Restore—conservative dentistry
5. Replace—prosthesis
6. Reconstruct—TMJ surgery
7. Regulate—control habit and symptoms.

56. Treatment of MPDS:
 For TMJ pain, auriculotemporal nerve block is given
 counselling of the patient
 Intake of soft diet and home exercises should be suggested
Medication
1. Aspirin
2. Piroxicam
3. Ibuprofen
4. Pentazocine
5. Valium/Librium
6. Methocarbamol
7. Amitriptyline

57. TRISMUS
Trismus, or lockjaw, is a painful condition in which the jaws do not
open fully. As well as causing pain, trismus can lead to problems
with eating, speaking, and oral hygiene.
Trismus occurs when a person is unable to open their mouth more
than 35 mm.
Most cases of trismus are temporary, typically lasting for less than 2
weeks, but some may be permanent.

58. Causes:
 Trauma
 Inflammation
 Dental Surgery
 Infection
 Cancer or cancer treatment

59. Symptoms:
 jaw not opening fully or opening to 35 mm or less
 jaw pain and cramping
 difficulty biting, chewing, or brushing the teeth
 inability to swallow some foods
 headaches
 earache

60. Risk Factors:
 having head or neck cancer
 undergoing radiation treatment for head or neck cancer
 recent oral surgery to remove a wisdom tooth
 recent trauma to the mouth or jaw
 having certain types of mouth infection

61. Treatment:
 Typically, treating the underlying condition should resolve many
cases of trismus.
 Generally, the earlier a person seeks treatment, the better the
outcome.
Medication:
Common medications for trismus include muscle relaxers
and nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve
pain.

62. Dislocation
Inability to close the mouth due to the complete translocation of the
condyle to the anterior articular eminence.
Causes: Trauma
Weakening of fibrous capsule
Muscle spasm
Abnormal chewing habits
Loosening of the joints ligaments

64. Subluxation
Subluxation is when the joint is still partially attached to the bone.
Causes: -congenital weakness of the capsule
- malformation of the condyles
- joint strained or injured during general anesthesia, yawning
- positional pressures during sleep

65. SUMMARY
 The temporomandibular joint (TMJ), also known as the
mandibular joint, is an ellipsoid variety of the right and left
synovial joints forming a bicondylar articulation.
 The common features of the synovial joints exhibited by
this joint include a fibrous capsule, a disk, synovial
membrane, fluid, and tough adjacent ligaments.

66. REFERENCE
 B. D. Chaurasia 5th edition Volume 3
 Textbook of Oral and Maxillofacial surgery – Neelima
Mallik