temporomandibular joint

2. By – Dr. JJ

3.  INTRODUCTION
 PECULIARITY OF TMJ
 COMPONENTS
 VASCULAR SUPPLY
 INNERVATIONS
 RELATIONS
 MOVEMENTS
 AGE CHANGES
 DEVELOPMENT
 CLINICAL SIGNIFICANCE
 TMJ DISORDERS
 CONCLUSION
 REFERENCES

5. CLASSIFICATIONS OF JOINTS
STRUCTURAL CLASSIFICATION:
FIBROUS JOINT
CARTILAGENOUS JOINT
SYNOVIAL JOINT
FUNCTIONAL CLASSIFICATION:
SYNARTHROSIS
AMPHIARTHROSES
DIARTHROSIS

6.  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.
Dorland WA: Medical Dictionary. Philadelphia and London,
Saunders
Co., 1957

7.  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 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.
Williams PL: Gray’s anatomy, in Skeletal System (ed 38).
Churchill. Livingstone, London, 1999, pp 578-582

8. 1. Bilateral diarthrosis – right & left function together
2. Articular surface covered by fibrocartilage
3. Only joint in human body to have a rigid endpoint of
closure that of the teeth making occlusal contact.

9. 4. In contrast to other diarthrodial joints TMJ is last
joint to start develop, in about 7th week in utero.
5. Develops from two distinct blastema.
Peculiarity of TMJ…….

11. COMPONENTS OF THE TMJ
MANDIBULAR CONDYLES
ARTICULAR EMINENCE
MUSCLES OF THE TMJ:
MUSCLES OF MASTICATION
SOFT TISSUE COMPONENTS:
ARTICULAR DISC
JOINT CAPSULE
LIGAMENTS

12.  An ovoid process seated
atop a narrow mandibular
neck. It’s the articulating
surface of the mandible.
 It is convex in all directions
but wider latero-medially
(15 to 20 mm) than antero-
posteriorly (8 to 10mm).

13. It has lateral and medial
poles:
 The medial pole is
directed more posteriorly.
 Thus, if the long axes of
two condyles are extended
medially, they meet at
approximately the basion
on the anterior limit of the
foramen magnum, forming
an angle that opens toward
the front ranging from
145° to 160°

14.  The articular surface of
the temporal bone is
situated on the inferior
aspect of temporal
squama anterior to
tympanic plate.

15.  Articular eminence:
This is the entire
transverse bony bar
that forms the anterior
root of zygoma. This
articular surface is
most heavily traveled
by the condyle and
disk as they ride
forward and backward
in normal jaw function.

16.  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.

17.  The articular disc is a roughly oval, firm, fibrous plate.
• It is shaped like a peaked cap that divides the joint
into a larger upper compartment and a smaller
lower compartment.

18.  Hinging movements take place in the lower
compartment and gliding movements take place in
the upper compartment.

19.  The disc is attached all around the joint capsule
except for the strong straps that fix the disc directly
to the medial and lateral condylar poles, which
ensure that the disc and condyle move together in
protraction and retraction.
Williams PL: Gray’s anatomy, in Skeletal System (ed 38).
ChurchillLivingstone, London, 1999, pp 578-582

20.  Thin sleeve of tissue completely
surrounding the joint.
 Extends from the circumference of the
cranial articular surface to the neck of
the mandible.
Patnaik VVG, Bala S,Singla Rajan K: Anatomy of temporomandibular joint A
review. J Anat Soc India 49(2):191-197, 2010

21.  Anteriorly, the capsule has an orifice through which the
lateral pterygoid tendon passes. This area of relative
weakness in the capsular lining becomes a source of
possible herniation of intra-articular tissues, and this, in
part, may allow forward displacement of the disc.

23.  The ligament on each side of the
jaw is designed in two distinct
layers.
 The wide outer or superficial
layer is usually fan-shaped and
arises from the outer surface of
the articular tubercle and most
of the posterior part of the
zygomatic arch.
 There is often a roughened,
raised bony ridge of attachment
on this area.

24.  Arises from the angular
spine of the sphenoid
and petrotympanic
fissure.
 Runs downward and
outward.
 Insert on the lingula of
the mandible.

25.  The ligament is related –
1. Laterally - lateral pterygoidmuscle.
2. posteriorly - auriculotemporal nerve.
3. anteriorly - maxillary artery.
4. Inferiorly - the inferior alveolar nerve
and vessels a lobule of the parotid
gland.
5. Medially - medial pterygoid with the
chorda tympani nerve and the wall of
the pharynx with fat and the
pharyngeal veins intervening.

26.  The ligament is
pierced by the
myelohyoid nerve and
vessels.

27.  This is a specialized dense, local concentration of deep
cervical fascia extending from the apex and being
adjacent to the anterior aspect of the styloid process and
the stylohyoid ligament to the mandible’s angle and
posterior border.

28.  Oto mandibular ligament
 Disco malleolar ligament
 Mallelo mandibular ligament

29.  The synovial fluid comes from two sources: first, from
plasma by dialysis, and second, by secretion from type
A and B synoviocytes with a volume of not more than
0.05 ml.

30.  It is clear, straw-colored viscous fluid.
 It diffuses out from the rich cappillary network of
the synovial membrane.
Contains:
 Hyaluronic acid which is highly viscous
 May also contain some free cells mostly
macrophages.
Functions:
 Lubricant for articulating surfaces.
 Carry nutrients to the avascular tissue of the joint.
 Clear the tissue debris caused by normal wear and
tear of the articulating surfaces.

31.  The masticatory muscles surrounding the joint are
groups of muscles that contract and relax in harmony so
that the jaws function properly.
 When the muscles are relaxed and flexible and are not
under stress, they work in harmony with the other parts
of the TMJ complex.
 The muscles of mastication produce all the movements
of the jaw.
 These muscles begin and are fixed on the cranium
extending between the cranium and the mandible on
each side of the head to insert on the mandible.

32. Moves mandible - mastication & speech
1.Masseter
2.Temporalis
3.Lateral pterygoid
4.Medial pterygoid

33.  Masseter superficial layer Elevates
middle layer mandible
deep layer
 Temporalis temporal fossa elevates
temporal fascia grinding

34.  Lateral pteryoid upper head depression
lower head protrusion
grinding
 Medial pterygoid superficial head elevates
deep head protrusion

35.  The way the teeth fit together may affect the TMJ
complex.
 A stable occlusion with good tooth contact and
interdigitation provides maximum support to the
muscles and joint, while poor occlusion (bite
relationship) may cause the muscles to malfunction
and ultimately cause damage to the joint itself.
 Instability of the occlusion can increase the pressure on
the joint, causing damage and degeneration.

36.  Branches of External Carotid Artery
 Superficial temporal artery
 Deep auricular artery
 Anterior tympanic artery
 Ascending pharyngeal artery
 Maxillary artery

37.  The Blood supply to TMJ is only
Superficial, i.e. there is no blood supply
inside the capsule.

38.  Sensory innervation of the TMJ is
derived from the auriculotemporal
and masseteric branches of
trigeminal nerve.

39.  LATERAL SURFACE : PREAURICULAR AND
PAROTID NODES
 POSTERIOR AND MEDIAL SURFACE :
SUBMANDIBULAR NODES THROUGH
EXTERNAL
CAROTID ARTERY
 ANTERIOR SURFACE : PAROTID NODES

40. Anteriorly - Mandibular notch
Lateral pterygoid
Masseteric nerve
and
artery

41. Posteriorly - parotid gland
Superficial temporal vessels
Auriculotemporal nerve

42. Laterally –
Skin and fascia
Parotid gland
Temporal branches of facial nerve

43. Medially - Tympanic plate (separates from ICA)
spine of sphenoid
Auriculotemporal & chorda tympani nerve
middle meningeal artery
maxillary artery

44. Superiorly –
middle cranial fossa
middle meningeal vessels

45. Inferiorly –
maxillary
artery
&
vein

47.  Rotational / hinge movement in first 20-25mm
of mouth opening.
 Translational movement after that when the
mouth is excessively opened.

48.  Translatory movement – in the superior part of the
joint as the disc and the condyle traverse anteriorly
along the inclines of the anterior tubercle to provide an
anterior and inferior movement of the mandible.

49. Mouth closed Mouth open
 Hinge movement – the inferior portion of the joint
between the head of the condyle and the lower surface
of the disc to permit opening of the mandible.

51. 1. Depression Of Mandible
 Lateral pterygoid
 Digrastric
 Geniohyoid
 Mylohyoid

52. 2. Elevation of Mandible
 Temporalis
 Masseter
 Medial
Pterygoids

53. 3. Protrusion of Mandible
 Lateral Pterygoids
 Medial Pterygoids

54. 4. Retraction of Mandible
 Posterior fibres of Temporalis

55.  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.

56.  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.

58.  The mandible develops from Meckel’s cartilage,
which provides the basic support for the lower
jaw and terminates dorsally into Malleus.
 The primary joint exists till the 4th month of intra
uterine life.
 At 3 month of gestation the secondary joint
begins to form

60.  Embryologically, the primary jaw joint
between incus & malleus persists in the fetal
period till 4 months of IUL.
 It is then replaced by secondary joint, as
incus & malleus recede into middle ear and
initiate sound conduction.
 It is phylogenetically replaced by secondary
joint, which is the TMJ.

61. BONY STRUCTURES:
Condyle- composed of cancellous bone
covered by a thin compact bone
- trabeculae radiate from neck of condyle
Fossa- roof consists of thin layer of compact
bone
Articular eminence- spongy bone covering thin
layer of compact bone

62. Fibrocartilagenous zone:
- Collagen fibers in bundles forms net work
- resist compressive & lateral forces
Calcified zone:
- deepest zone,chondrocytes & chondroblasts
- active site for remodelling

63.  Examination
 Disorders

65. Examination
 To palpate the joint and its associated muscles
effectively, have the patient go through all the
movements of the mandible in relationship to the
TMJ while bilaterally palpating the joint just
anterior to the external acoustic meatus of each
ear.

66.  This includes asking the patient to open and
close the mouth several times and then to
move the opened jaw to the left, and then to
right, and then forward.
 To further assess the mandible moving at the
TMJ, use digital palpation by gently placing a
finger into the outer part of EAM.

67. TMJ DISORDERS

68. Temporomandibular Joint Disorder
• The disorder and resultant dysfunction can result in
significant pain and impairment
• Because the disorder transcends the boundaries between
several health-care disciplines in particular,
- Dentistry
- Neurology
- Physical therapy
- Psychology

69. 1. Masticatory Muscle Disorders
a. Protective co-contraction
b. Local muscle soreness
c. Myofascial pain
d. Myospasm
e. Centrally mediated myalgia
2. Temporomandibular Joint Disorders
A. Derangement of condyle-disc complex
a. Disc displacements
b. Disc dislocation with reduction
c. Disc dislocation without reduction
B. Structural incompatibility of the articular surfaces
a. Deviation in form - Disc
- Condyle
- Fossa
b. Adhesions - Disc to condyle
- Disc to fossa

70. c. Subluxation ( hypermobility)
d. Spontaneous dislocation
C. Inflammatory Disorders of TMJ
a. Synovitis
b. Retrodiscitis
c. Arthritides
- Osteoarthritis
- Osteoarthrosis
- Polyarthritides
d.. Inflammatory disorders of associated structures
a. Temporal tendonitis
b. Stylomandibular ligament inflammation
3. Chronic mandibular hypomobility
A. Ankylosis
- Fibrous
- Bony
B. Muscle contracture
- Myostatic
- Myofibrotic
C. Coronoid impedance

71. 4. Growth Disorders
A. Congenital and developmental bone disorders
a. Agenesis
b. Hypoplasia
c. Hyperplasia
d. Neoplasia
B. Congenital and developmental muscle disorders
a. Hypotrophy
b. Hypertrophy
c. Neoplasia
.

72. Predisposing Factors
• Modification of chewing surfaces of the teeth through dental
neglect or accidental trauma
• Speech habits resulting in jaw thrusting.
• Excessive gum chewing or nail biting.
• Excessive jaw movements associated with exercise.
• Repetitive subconscious jaw movements
associated with bruxing or clenching.
• Size of foods eaten

73. Signs and Symptoms
• Jaw pain and/or stiffness
• Headaches, usually at the temples and
side of head.
• Vague tooth soreness or toothache which often move around
the mouth.
• Sensitive teeth
• Painful or tender jaw joint
• Difficulty in opening jaw and ear pain.
• Pain and fatigue when eating hard or chewy foods

74. Treatment
TMD treatments are conservative and reversible

75. Treatment
Conservative Treatments
• Conservative treatments are as simple as possible and
are used most often because most patients do not have
severe, degenerative TMD
• Conservative treatments do not invade the tissues of the
face, jaw or joint

76. Treatment
Reversible treatments do not cause permanent, or
irreversible, changes in the structure or position of the jaw or
teeth.

77. TMJ Symptom Relief
• It is important to avoid large movement of the jaw such as
singing
and wide yawning.
• Do not apply pressure with your hand against your jaw for an
extended time period during sleep.

78. TMJ Symptom Relief
Choose soft food and stay away from foods requiring
repetitive chewing or the mouth to open wide. In particular,
avoid chewing gum and raw carrots.

79. TMJ Symptom Relief
Continue to receive dental treatment for any teeth requiring
restoration. Tooth decay may affect the bite, a contributing
factor to TMJ..

80. TMJ Symptom Relief
Medications
• Non-steroidal anti-inflammatory drugs (NSAIDs like
ibuprofen), muscle relaxants, anti-anxiety medications
and in some cases anti-depressants.
• The choice of medication depends on the intensity of
the disorder and the medical history.
• However, the need for medication is greatly reduced
when treatment is received by an experienced TMJ
dental professional.

81. Dental Appliances
TMJ Symptom Relief
• Dentist may prescribe a dental appliance such as a mouth
guard or splint to reduce the effects of tooth grinding and
clenching.
• Such appliances may also help improve your bite and the
ability for the lower jaw to fall properly into the
temporomandibular joint socket.

82.  Myofascial pain and dysfunction
 Internal derangement
 Osteoarthrosis
 Dislocation

83.  Refers to a group of poorly defined muscle disorders
(eg, fibromyalgia) characterized by diffuse facial pain
and episodic limited jaw opening.
 May result from parafunctional habits and significant
relationship to psychophysiologic disorders such as
stress or depression.

84.  Abnormal relationship of the articular disc to the
mandibular condyle, fossa,and articular eminence,
interfering with the smooth action of the joint
(Dolwick 1983).
 Is a localized mechanical fault within the joint.

85.  Is a non- painful, localized degenerative joint disease that
mainly affects bone and articular cartilage.
 It is often idiopathic, but predisposing factors such as old
age, repetitive trauma (bruxism), abnormal joint
posturing, or multiple surgical procedures may be
involved. If painful, then referred to as osteoarthritis.

86.  Fusion of the TMJ is the occasionallate outcome
of trauma or infection.

88.  TMD mostly affects people in the 20 – 40 age
group, and the average age is 33.9 years.
 About 60-70% of the population have features of
TMDs.
 About 20-30% report symptoms of TMDs.
 About 5% of people with TMD symptoms actually
seek treatment.
 The female: male ranges from 3:1• Natl J Maxillofac Surg. 2014 Jan-Jun; 3(1): 25–30.
• Prevalence of Temporo-mandibular Joint Disorders in
Symptomatic and Asymptomatic Patients: Int J Adv Sci
2014; 1(6): 14-20

89.  Indicated for a subset of temporomandibular
disorders:
1.Internal derangment; 2.Degenerative joint
disease; 3. Rheumatoid arthritis; 4.
Infectious arthritis; 5.Mandibular dislocation;
6.Ankylosis; 7.Condylar hyper/hypoplasia

90.  Examples of surgical procedures that are used in
TMD, arthrocentesis, arthroscopy, menisectomy, disc
repositioning, condylotomy or joint replacement.
 Invasive surgical procedures in TMD may cause
symptoms to worsen.
 Menisectomy, also termed discectomy refers to
surgical removal of the articular disc.

91.  Discectomy
 Disc repositioning
 Condylotomy
 Arthrocentesis
 Arthroscopy
 Partial and total joint replacement

92. • TMJ plays important role in chewing ,
speaking, swallowing etc.
• It is one of most important and most poorly
understood of the many joints in the body.
• We are just now beginning to understand it
and give it the respect and careful treatment it
deserves as an integral functioning part of the
dental anatomy.

93. 1. Sicher and Dubrul's Oral Anatomy by E. Lloyd Dubrul
2. The Tmj Book by Andrew S. Kaplan, Jr. Williams Gray
3. B.D. Chaurassia’s human anatomy 4th edition vol. 3 The Head
& Neck.
4. Williams PL: Gray’s anatomy, in Skeletal System (ed 38).
Churchill Livingstone, London, 1999, pp 578-582
5. Fonseca volume 2 by Robert D. Marciani
6. Temporomandibular Disorder, A Problem Based
Approach by Dr Robin J. M. Gray & Dr M. Diad Al – Ani
7. Surgical Approaches To Facial Skeleton By – Edward
Ellis III & Nmichael F. Zide
8. Surgery Of TMJ 2nd ed. by David A. Keith

94. 1. Dorland WA: Medical Dictionary. Philadelphia and London, Saunders Co.,
1957
2. Williams PL: Gray’s anatomy, in Skeletal System (ed 38). Churchill
Livingstone, London, 1999, pp 578-582
3. Yale SH: Radiographic evaluation of the temporomandibular joint. J Am
Dent Assoc 79(1):102-107, 1969
4. Patnaik VVG, Bala S,Singla Rajan K: Anatomy of temporomandibular joint?
A review. J Anat Soc India 49(2):191-197, 2000
5. Harms SE, Wilk RM: Magnetic resonance imaging of the
temporomandibular joint. Radiographics 7(3):521-542, 1987
6. Tallents RH, Katzberg RW, Murphy W, et al: Magnetic resonance imaging
findings in asymptomatic volunteers and symptomatic patients with
temporomandibular disorders. J Prosthet Dent 75(5):529-533, 1996
7. Helms CA, Kaplan P: Diagnostic imaging of the temporomandibular joint:
recommendations for use of the various techniques. AJR Am J Roentgenol
154(2):319-322, 1990
8. Helms CA, Kaban LB, McNeill C, et al: Temporomandibular joint:
morphology and signal intensity characteristics of the disk at MR
imaging. Radiology 172(3):817-820, 1989

95. 9. Kreutziger KL, Mahan PE: Temporomandibular degenerative joint disease.
Part II. Diagnostic procedure and comprehensive management. Oral Surg
Oral Med Oral Pathol 40(3):297-319, 1975
10. Toller PA: Temporomandibular capsular rearrangement. Br J Oral Surg
11(3):207-212, 1974
11. McMinn, RMH: Last’s anatomy regional and applied, in Head and Neck and
Spine. Churchill Livingstone, Edinburgh, London, 1994, p. 523
12. Roberts D, Schenck J, Joseph P, et al: Temporomandibular joint: magnetic
resonance imaging. Radiology 154(3):829-830, 1985
13. Harms SE, Wilk RM, Wolford LM, et al: The temporomandibular joint:
magnetic resonance imaging using surface coils. Radiology 157(1):133- 136,
1985
14. Edelstein WA, Bottomley PA, Hart HR, et al: Signal, noise, and contrast in
nuclear magnetic resonance (NMR) imaging. J Comput Assist Tomogr
7(3):391-401, 1983
15. Westesson PL, Katzberg RW, Tallents RH, et al: Temporomandibular joint:
comparison of MR images with cryosectional anatomy. Radiology 164(1):59-
64, 1987

96.  Muscles of Mastication (RGUHS 2007,20 marks)
 Temporomandibular joint (RGUHS 2005, 10 marks)